PCI-E Gen 2.0 Bug X38/ X48/X58

Hi guys

In collaboration with a number of users on the nVidia forums and ASUS forums I am trying to collect data as to what boards are effected by the notorious PCI-E Gen 2.0 bug which appears to be effecting Dual PCI-E 16 Intel Boards and nVidia cards.

The symptoms of the PCI-E Gen 2.0 bug are that your graphics card only operates at PCI-E Gen 1.1 mode.
For example

http://img13.imageshack.us/img13/4130/pcie201stslot.jpg

This GTX 285 is only operating @ PCI-E 1.1 x16 on an X38 based motherboard (ASUS P5E3).

On gigabyte boards the symptoms are slightly different.
http://img215.imageshack.us/img215/4...en11bug.th.jpg

Where here the board does present itself as a Gen 2.0 board, the card only runs at Gen 1.1

I and a few other users have been constantly trying to get this issue resolved, but motherboard vendors are not very helpful.

The information we have is

1) PCI-E Gen 2.0 has been disabled on X38/x48/X58 boards with a certain undisclosed, yet confirmed by nVidia SMBIOS bug in Intel BIOSes as of April 2009.

2) Intel DX38BT motherboard with BIOS 2006 is NOT effected by the PCI-E Gen 2.0 bug, apparently this contains a fix.

3) DMI information on ASUS X38 boards is odd, says our PCI-E16 slots are empty?!

4) Intel resolved a Slot mismatch issue on their boards in July 2009 stating it resolved a PCI-E Gen 2.0 issue.

5) Most X48 boards are unaffected, and even fewer X58 boards have this bug.

6) nVidia 9800GX2 and GTX295 do not appear to show this bug as their NF200 chips report the PCI-E link speed direct to the GPU's

Please if you have the time could you take a screenshot of GPU-Z showing your card's PCI-E transfer rate and put this alongside a CPU-Z screenshot showing what motherboard and what BIOS revision you are running.

Many thanks

John

Hi John, so you're saying that even though GPU-Z shows the bus interface at x16, it only runs at PCI-E 1.1 x16 but not PCI-E 2.0 x16? I have some screenshots and hopefully they help. Does it only affect to Nvidia card but not ATI?

My board is a Maximus Formula X38 that flash to a Rampage Formula. I have the GTX 275, GTX 285, GTX 295 as shown below:

http://img144.imageshack.us/img144/9...01035358pm.jpg

http://img39.imageshack.us/img39/4319/47201035503pm.jpg

http://img192.imageshack.us/img192/1...01040232pm.jpg

http://img88.imageshack.us/img88/4761/47201040257pm.jpg

Quote:

---

Originally Posted by iTravis

Hi John, so you're saying that even though GPU-Z shows the bus interface at x16, it only runs at PCI-E 1.1 x16 but not PCI-E 2.0 x16? I have some screenshots and hopefully they help. Does it only affect to Nvidia card but not ATI?

My board is a Maximus Formula X38 that flash to a Rampage Formula. I have the GTX 275, GTX 285, GTX 295 as shown below:

http://img144.imageshack.us/img144/9...01035358pm.jpg

http://img39.imageshack.us/img39/4319/47201035503pm.jpg

http://img192.imageshack.us/img192/1...01040232pm.jpg

http://img88.imageshack.us/img88/4761/47201040257pm.jpg

---

Thanks for the information iTravis
What we see here is that your GTX 275 and GTX 285 are running in PCI-E 1.1 mode. The GTX 295 corresponds with tests performed on 9800GX and GTX 295 Single PCB whereby the NF200 reports PCI-E 2.0 to the GPU's and the driver.

ATi cards appear unaffected, unless you use HWinfo32 (or some other program that measures PCI-E Bandwidth). For some reason ATi cards do not report information like nVidia cards (such as memory usage, etc)

Thanks for the information, what is concerning is that Rampage Formula does not have this issue, yet you flashed your BIOS to a Rampage Formula and you still have this issue :(
John

Well if that's the case the bug is also in P35 chipset as well, here's my 9800GTX+ on an Asus P5K Pro.

http://img101.imageshack.us/img101/3051/evga9800gtx.jpg

Quote:

---

Originally Posted by iTravis

Well if that's the case the bug is also in P35 chipset as well, here's my 9800GTX+ on an Asus P5K Pro.

[IMG]http://img101.imageshack.us/img101/3051/evga9800gtx.jpg[IMG]

---

I thought PCI-E 2.0 was released with the x38 chipset :confused:

Quote:

---

Originally Posted by stardust8750

I thought PCI-E 2.0 was released with the x38 chipset :confused:

---

Correct, The X38 was Intel's first PCI-E Gen 2.0 motherboard. The P35 is a PCI-E 1.1 motherboard.

P35 Chipset Features

X38 Chipset Features

Thanks for your help.

John

So how about this? I have this 8800GT before I changed to the 9800GTX+, run on same motherboard.

http://img46.imageshack.us/img46/502...10111459pm.jpg

Quote:

---

Originally Posted by iTravis

So how about this? I have this 8800GT before I changed to the 9800GTX+, run on same motherboard.

http://img46.imageshack.us/img46/502...10111459pm.jpg

---

Those are really old drivers :shakes:
What you see there is a detection of a PCI-E Gen 2.0 capable slot, but not a PCI-E 2.0 capable card.

If you run HWinfo32 it will give you more detailed information

I am awaiting more information from ASUS R&D department, but what I can tell you is that genuine Rampage Forumla's do not exhibit this issue, yet Maximum Formula's and Maximum Formula's flashed to Rampage Forumula's do have this problem :confused:

http://img209.imageshack.us/img209/7056/pcie.jpg

No laughing at my GPU clocks. I get PSOD even with minor overclocks. :(

Thank you very much for your contribution YukonTrooper :)
It appears your motherboard is not effected by this annoying bug.
We are still no closer to finding a fix, what we have noticed is that the DMI slot structure is all wrong!? This information has been passed onto ASUS, so who knows....fingers crossed a fix is in sight.
John

eVGA 790i Ultra:




http://img651.imageshack.us/img651/1204/vgaxfgn.jpg
By chispy at 2010-04-02

Quote:

---

Originally Posted by JohnZS

Those are really old drivers :shakes:
What you see there is a detection of a PCI-E Gen 2.0 capable slot, but not a PCI-E 2.0 capable card.

---

The strange thing is... his 8800gt shot was when it was in the same P35 board ( PCIe 1.1 as mentioned ) yet it reports PCIE 2.0 ( by the way the 8800gt is PCIE 2.0, it was Nvidias first If I recall ) Rather bizarre...

EDIT : I looked into it and some people seem to believe that a newer revision of the P35 chipset supports PCIE2.0 but unofficially... Wether this is true or not is beyond me. Just thought this was interesting.

my EVGA P55 FTW does this when running 2 cards, it reports the pci-e 2.0 X16 slot but only runs it at pci-e X16@ X8 the X8 is normal but it should say X8 2.0 it doesnt, but with one card it shows pci-e 2.0X16@ X16 2.0

Thanks for taking the time to test and reply guys :up:

chispy

I have noticed that your card is running @ x4 Gen 2.0. Have you by any chance got dirt on the slots or the card? Or are you running Tri SLi or something?!?

It is unusual to see an nForce 790 based motherboard exhibit such a strange problem.

Chickenfeed
Ahh thanks for that, this would explain the card and slot mismatch on your GPU-Z screenshot. A PCI-E 2.0 card running on a PCI-E 1.1 slot. I have not heard about some boards being PCI-E 2.0, however what you say would make sense if they were very late production models out at the same time as the X38 and X48 boards, but just before the P45 was released?!

Thanks for the information overclocking101
Similar behaviour has been noticed on a ASUS Maximus III Extreme, however that was running PCI-E Gen 1.1 with just one card in the system (@ x16) and then x8 with two cards in the system. Perhaps your eVGA board is half fixed? ;)

I would keep an eye out for BIOS updates.

As far as I am aware P45 boards are immune to this issue, however if any P45 readers are out there, please do provide screenshots confirming or contradicting what we have found so far with P45 boards. Anymore X38 and X48 users will be most welcome..

Thanks

John

hi all ive fixed the prob and its simple to do but ide rather not post it so john if u get the time pm me ill tell u how to fix this and get u pci e to 2.0

Quote:

---

Originally Posted by death

hi all ive fixed the prob and its simple to do but ide rather not post it so john if u get the time pm me ill tell u how to fix this and get u pci e to 2.0

---

I'm not affected by this bug, but why would you decide not to post the fix for those that could use it? Unless the fix involves messing around with high voltages, I'm a little bewildered. :shrug:

ok ill post it
well ide been doing alot of reading about this prob that i have and loads of other have and then found out about the sli patch that nv drivers see u board as a x58 and

well we all no about the sli patch that lets none sli board do sli long as they have 2 x 16 pcie lanes well what it does it make the nv drivers think u got an x58 board well ive got a p5e x38 board and before i did this like 10 mins ago my pcie was at v1.1 after installing the patch to make the drivers think i have a x58 i now have v2.0 pcie

before
http://i274.photobucket.com/albums/j...1976/oyess.jpg

after
http://i274.photobucket.com/albums/j...976/wicked.jpg

the difference is amazing over 2k more from v1.1 to v2.0 i hope this is going to make lots happy
the prog is here

what it is is amazing it really is that simple to do cant post it on nv forums as it bet it will get deleted as soon as its read but there u go ever one i can say ive fixed a prob that been about for years


and i no but i do feel veryy happppppyyy

What I found with my Asus Crosshair 3 motherboard and the GTX480 I'm using, that when I run GPUz it will show PCI-E 2.0 x16 @ x16 2.0 but only for like 30 seconds and then it will change to PCI-E x16 @ x16.

Brillian plan death. I just don't think it will work on my motherboard....... or will it?

EDIT.... OOPS I just saw that my board is on the list of those the pacth were tested on. GREAT. Thanks, I will try it out.

well the patch was ment to let just about ever board with 2x 16 pcie slots have sli but in the same way it made it it has allso fixed the bug that nvidia put in there drivers to stop x38 board haveing the right specs

THERE IS NO BUG!

GPU-Z STOPS DISPLAYING 2.0 WHEN GPU DOWNCLOCKS, AS VoodooProphetII NOTICED.

Quote:

---

Originally Posted by VoodooProphetII

What I found with my Asus Crosshair 3 motherboard and the GTX480 I'm using, that when I run GPUz it will show PCI-E 2.0 x16 @ x16 2.0 but only for like 30 seconds and then it will change to PCI-E x16 @ x16.

---

HERE ARE THE PICTURES:

Immediately after start:
http://img576.imageshack.us/img576/9115/pcie201.jpg

Few seconds later - downclock and no 2.0:
http://img576.imageshack.us/img576/2111/pcie202.jpg

Again few soconds later - more downclock, stays the same:
http://img52.imageshack.us/img52/1743/pcie203.jpg

Just to clarify things, it is not a bug that nVidia put into the drivers, but an intentional block. Apparently (and this is from nVidia themselves when I asked them about this Gen 1 issue) it is intentional to avoid a potential system hang!

Quote:

---

Hi John,
I am sorry however there is nothing we can do in this case. The Intel x38 chipset was Intel's first generation PCI-E 2.0 implementation and unfortunately has some PCI-E 2.0 bugs, one that causes the graphics card to hang when changing P states. The only Intel PCI-E 2.0 chipset which shows these bugs is the Intel x38 chipset. If you see any other Intel chipset reporting PCI-E 1.0 speeds with our GPUs, please let me know. The best way to check is to run a 3D program in the background as this will change the P state of the graphics card from PCI-E 1.0 to PCI-E 2.0. This throttling is done to conserve power when the user is running basic Windows tasks

---

However, once again well done death :)
It is about time PCI-E 2.0 was re-enabled properly

EDIT
For those of you doubting the presence of this bug, you are confusing things. Basically by design the cards GT200 or newer (with forceware 190+) should revert back to PCI-E 1.1 in the 2d mode i.e. 300Mhz (or whatever your lowest Pstate clocks are). HOWEVER when you run a 3d application it should change to Gen 2.0 full link width! This change does not happen on motherboards/systems effected by the Gen 1.1 bug. They ALWAYS remain in Gen 1.1 mode, regardless of how long you run furmark/3dmark/*insert game name here*

John

Apparently it's still an issue with Nvidia cards on X38 chipset, from GTX 275, 285, not 295 though, to GTX 470 and GTX 480. I run FurMark and it still doesn't show PCI-E 2.0 x16.

I do not know the full ins and outs, but apparently the whole issue is a form of crash prevention by nVidia. They believe that when switching to an L1 ADSPM state the X38 chipset has a bug/glitch which can cause a hard freeze. FYI The 9800GX2 and GTX 295, only stay in the L0 state (something to do with their design). Therefore all GPU's with multiple P states (G200 and newer) are effected by this lock on the X38 chipset. Apparently the X48 is NOT effected so in theory Gen 2.0 should work correctly on those boards.
I am still waiting to hear from ASUS about this as Gen 2.0 is broken on X38, therefore they need to fix it, or at least replace with equivalent X48 based board.
It would be interesting to know if the work around posted causes any stability issues :)
John

donmarkoni thank you.... I've just tested my mobo and graphics card and it looks like you are correct with your assessment. GPUz would show 1.1 after a few seconds and then when I run OCCT to stress the GPU and the test starts it would switch back to 2.0

Thanks a lot.

Sadly this patch does not work on the ASUS P5E3 which has a 1MBit BIOS ROM compared to other ASUS X38/X48 boards which have a 2MBit BIOS ROM.
I tried the patch posted, but I keep getting stuck in an endless loop of "Windows Startup Repair".
This is Windows 7 x64.
John

hmm should work since it dont touch u bios all it does its place files on u pc that at the start tell windows u running an x58 but hmm

I have a 'problem' with SLI 480GTX on a X58 motherboard - P6X58D Premium.
GPU-Z shows one of the 2 working in 'full' PCIE 2.0 X16, but the other stays in PCIE 2.0 X8.
HWINFO32 shows v2.0 X8 for both, in 'idle mode' 2.5Gb/s and during (windowed) Furmark still X8 but at 5.0Gb/s.

Would be interesting to know if they really are running in v2.0 X16...

And yes, I have the MB BIOS set to 'x16-x16-x1' for the 3 PCIE x16 slots.

Quote:

---

Originally Posted by nusihb

I have a 'problem' with SLI 480GTX on a X58 motherboard - P6X58D Premium.
GPU-Z shows one of the 2 working in 'full' PCIE 2.0 X16, but the other stays in PCIE 2.0 X8.
HWINFO32 shows v2.0 X8 for both, in 'idle mode' 2.5Gb/s and during (windowed) Furmark still X8 but at 5.0Gb/s.

Would be interesting to know if they really are running in v2.0 X16...

And yes, I have the MB BIOS set to 'x16-x16-x1' for the 3 PCIE x16 slots.

---

Check the details of the lanes for cards in Everest.
It'll tell you exactly where the stuff is connected, perhaps GPU-Z/HWInfo may have issues when cards downclock/upclock on your system.

Hm, where in Everest (v550_2100) do I find info about current PCIE mode?
Can't find it anywhere...

Quote:

---

Originally Posted by nusihb

Hm, where in Everest (v550_2100) do I find info about current PCIE mode?
Can't find it anywhere...

---

Motherboard --> Chipset --> PCI Express Controllers

You'll have a list here of all the available lanes, devices on it and modes the devices are in.

Thanks!
Blind as usual... anyways, Everest is showing the following for the PCIE 2.0 bus:
#1 x1 Marvell SATA 6Gb/s controller
#2 x1 NEC SUB 3.0 controller
#3 x8 GTX480
#7 x16 GTX480

Seems like GTX480 in the first slot (closest to CPU) is 'stuck' in x8??
Bad card or bad m/b?

Will switch the 480s later this week to see if things changes.

Quote:

---

Originally Posted by nusihb

Thanks!
Blind as usual... anyways, Everest is showing the following for the PCIE 2.0 bus:
#1 x1 Marvell SATA 6Gb/s controller
#2 x1 NEC SUB 3.0 controller
#3 x8 GTX480
#7 x16 GTX480

Seems like GTX480 in the first slot (closest to CPU) is 'stuck' in x8??
Bad card or bad m/b?

Will switch the 480s later this week to see if things changes.

---

I have the same set up and mine are fine
Try loading default settings in the bios.


http://img28.imageshack.us/img28/156/64641818.jpg

I just wanted the OP to know that this thread saved me at least $400. I was going to buy a new video card for my rig to stop the slide show when I play BFBC2. Now, I play with 4XAA and 4X AF at 1680 x 1050 on my water cooled and moderately overclocked GTX 260. The patchworks perfectly. (Win 7 64bit)

Props to you, and all that contributed to this excellent thread! :up:

No problem at all MoreGooder
Thank David/Death for finding that the patch resolved the issue.
However there is still more the motherboard manufacturers and nVidia need to do for us. To cut a long story short ASUS have "closed the case" and will not resolve this bug.
I have requested nVidia add a feature to the forceware drives to add PCI-E Gen 2.0 support to be forced by the control panel as an option. (for Gen 2.0 cards on Gen 2.0 boards), I have also asked them to fix this bug.
In the meantime I am going to send another e-mail to ASUS asking why my GTX 295 runs slow compared to a GTX 295 on a Rampage Formula (X48). They are BOTH running at PCI-E Gen 2.0, however the transfer speed is crippled on my P5E3 to 4600MB/s yet on the Rampage Forumla it is happy @ 5300MB/s (this can cause a very minor performance issue with stuttering in games which are bandwidth sensitive and also reduce CUDA performance).
John

GTX460 has similar PCIE issues, the customised Quadro drivers I'm now using stopped that though. Didn't solve my biggest problem however, on my M2F for absolutely no reason on bootup / restarts my monitor signal just goes. Theres nothing wrong with the GTX460 itself I verified that by putting it in a M3N78.

Well the good news (and I hope it is good news) Ket, is that the nVidia driver team are now looking at ways of either resolving this issue, or getting the wheels put into motion to fix this issue.
I personally submitted a bug report AND an nVidia technical representative has posted into my thread on the nVidia forums saying that he has informed the driver team of this issue.
Fingers crossed and all that ;)
John

I don't think its a driver problem or the same issue would happen with the M3N78, I do think its a vBIOS problem though ;)

It is sort of a combination of driver Bug and chipset bug. The last official wording from nVidia back in June was that it could not be fixed.

Quote:

---

Hi John,
I am sorry however there is nothing we can do in this case. The Intel x38 chipset was Intel's first generation PCI-E 2.0 implementation and unfortunately has some PCI-E 2.0 bugs, one that causes the graphics card to hang when changing P states. The only Intel PCI-E 2.0 chipset which shows these bugs is the Intel x38 chipset. If you see any other Intel chipset reporting PCI-E 1.0 speeds with our GPUs, please let me know. The best way to check is to run a 3D program in the background as this will change the P state of the graphics card from PCI-E 1.0 to PCI-E 2.0. This throttling is done to conserve power when the user is running basic Windows tasks.

---

But after running ASUS into the ground with queries asking them to fix this "X38 Bug", they keep pointing me back towards nVidia. nVidia are now going to look into this again....

All an X38 board manufacturer has to do to fix the issue is modify a bios to hold the P-state at L0.

All nVidia has to do is modify their driver to never lower the P-state for the PCI-E link.

ACPI tables in the bios of the motherboard are what to change to "fix" the P-state.

A lot of manufacturers of GTX460s have removed a P-State in their vBIOS. Galaxy haven't, but Gigabyte have, as have Gainward, and Palit. A possible workaround for the problem is to set GPU voltage in the vBIOS @ 1v.

Thanks for the information STEvil and Ket.
I have passed on your suggestion to ASUS STEvil. Hopefully nVidia will resolve this by the driver as it makes more sense to check for X38 and then never lower the P State as opposed to check for X38 and then revert to legacy PCI-E Gen 1,0 mode.
Am I right in assuming Single PCB GTX 295's do not have support for P-State in their vBIOS? or is it just some quirk that the only nVidia cards running happily @ Gen 2.0 on my P5E3 is a GTX 295. 280 and 285 cards only run @ Gen 1.

By the way, Gen 1 does have a detrimental effect on the GTX 295's performance. (On occasional cold boots it reports Gen 2.0 but actually transfers @ Gen 1 speeds). FYI when a GTX 295 is running @ Gen 1 I lose 1000 Vantage points, 1000 3dmark 06 points, 0.2 WEI on the Graphics card.... and GTA IV is horrifically stuttering and laggy.

I have also spoken with someone called Chris who is heavily into CUDA and he says that Gen 1.0 cripples CUDA Performance on his GTX 480 (even in Linux as nVidia have put the lock on those drivers too).
So this IS an issue which needs resolving ;)
John

I should clarify what I said in my last post a bit. When I say set GPU voltage to 1v I mean for bootup / 2D clocks, 3D voltage is fine as is. As I said though, this is only a possible workaround. The problem is primarily with compatibility issues with GTX460s on a fair few boards. Both mobo manufacturers and nVidia should issue a new BIOS resolving the bootup issue. The driver for GTX460s doesn't really have anything to do with these bootup issues as the driver hasn't even had chance to initiate at that stage ;)

i ran the sli patch and i''m back to pci 2.0 now thanks alot. gained about 500 points in 3d06

I'm still testing my fix for the inexplicable signal loss on reboots with some systems and GTX460 cards so I won't go into too much detail but I believe I've nailed the problem. After some more testing I'll post further details.

I wonder how much this ACPI bug (thats what it is mostly) is responsible for stuttering in SLI and Crossfire?

If its a ACPI bug some boards you can disabled ACPI, anybody tried that?

Thanks Ket

Which one of these options would you suggest for disabling ACPI?
http://a.imageshack.us/img153/7833/acpi.jpg

STEvil
You have a very good point there, perhaps this is the cause of Microstutter?
Anyway with a GTX 295 (Single PCB), this issue manifests itself slightly differently. The card always reports as working @ PCI-E Gen 2.0.

However on cold boots and sometimes (on rare occasions) a reboot the card seems to lock itself into a crippled PCI-E transfer mode.
Take this screenshot here
http://a.imageshack.us/img153/9233/g...pciep5e3pg.jpg

That is ~20% of the transfer to BUS speed that it should be using, when a GTX 295 is in this state games stutter and performance is not very good at all. (WEI also drops by 0.2 on the Graphics card).

But when those transfer values are at 48xx MB/s everything is smooth and fine :)

Is this a symptom of the ACPI bug?
John

Try disabling each of them one at a time and see what happens, then try both :D

Well, I ended up getting a Blue Screen crash disabling ACPI 2.0 Support.
The annoying thing is everything was going well and very fluid in gaming, and then bham, the game froze (but sound continued), then the monitor went into an out of sync black screen, and then a BSOD popped up.

Quote:

---

BCCode: 117
BCP1: FFFFFA800746F4E0
BCP2: FFFFF880101A3CF8
BCP3: 0000000000000000
BCP4: 0000000000000000
OS Version: 6_1_7600
Service Pack: 0_0
Product: 256_1
Bucket ID: X64_0x117_Tdr:2_IMAGE_nvlddmkm.sys
Server information: 3940acc5-e624-406e-b30b-a893a96905bb

---

Never had that happen before :(
John

Looks like you would need to do a clean install with those BIOS settings and try then.

doubt a clean install will fix it. Non-ACPI HAL's are slower anyways. Remember the "Ricky Tweak" for single core CPU's on WinXP?

When you enable/disable some ACPI settings in the BIOS they are directly linked to some OS things and a format is the only way to set things up "correctly". Eitherway, these GTX issues are chipset specific. They can be fixed with a BIOS update but through lack of a better term most BIOS writers are dumb. They don't know how to fix problems that occur outside of normal chipset paramaters, even if their easy things to fix.

I am still awaiting a reply from ASUS, but in my previous correspondence from them in July they did say they spent a month working on the issue and could find no way to resolve it :(

Quote:

---

Hi John,



Our BIOS RD and BIOS RD leader have tried many ways to solve this problem by BIOS for more than one month

---

But that was on the 26/7. Hopefully your and StEvil's insight will sway their way of thinking.
I have also reported the issue to nVidia too so hopefully (fingers crossed) this will be resolved for everyone :)

John

Well, to solve the bootup issues some GTX460s have you can tell Asus all they have to do is get the BIOS to force the graphics cards P8 state at boot instead of the P12 state ;)

Thanks Ket :)
What constitutes a bootup issue? The card not being found on POST so leaving you with a lovely beep code? Or system booting with crippled performance (like with the GTX 295 on rare cold boots).
John

ASUS are not helping at all, in fact I am still waiting a response from the 8-8-2010 :(
John

nVidia have responded...

Quote:

---

There is a possibility that our software team can create a backdoor method where the graphics card won't change P states and then can always run at full speed but the downside of this is the graphics card will consume more power. Is this an ok alternative for everyone? I am still not 100% certain they will go ahead with this yet.

---

What would your opinions be guys?

John

My opinion is use software to control clock speeds, but leave p.state at full perf.

Quote:

---

Originally Posted by JohnZS

Thanks for the information STEvil and Ket.
I have passed on your suggestion to ASUS STEvil. Hopefully nVidia will resolve this by the driver as it makes more sense to check for X38 and then never lower the P State as opposed to check for X38 and then revert to legacy PCI-E Gen 1,0 mode.
Am I right in assuming Single PCB GTX 295's do not have support for P-State in their vBIOS? or is it just some quirk that the only nVidia cards running happily @ Gen 2.0 on my P5E3 is a GTX 295. 280 and 285 cards only run @ Gen 1.

By the way, Gen 1 does have a detrimental effect on the GTX 295's performance. (On occasional cold boots it reports Gen 2.0 but actually transfers @ Gen 1 speeds). FYI when a GTX 295 is running @ Gen 1 I lose 1000 Vantage points, 1000 3dmark 06 points, 0.2 WEI on the Graphics card.... and GTA IV is horrifically stuttering and laggy.

I have also spoken with someone called Chris who is heavily into CUDA and he says that Gen 1.0 cripples CUDA Performance on his GTX 480 (even in Linux as nVidia have put the lock on those drivers too).
So this IS an issue which needs resolving ;)
John

---

problem is only in idle mode and you don`t loose performance
http://a.imageshack.us/img837/9293/idleo.jpg

when you run 3D mode PCI-E returns to PCI-E 2.0
http://a.imageshack.us/img638/4821/stressg.jpg

same on 9800GT,GTX480/470 on X58

Quote:

---

Originally Posted by Maxforces

problem is only in idle mode and you don`t loose performance
-snip-
when you run 3D mode PCI-E returns to PCI-E 2.0
-snip-

same on 9800GT,GTX480/470 on X58

---

try reading the rest of the thread.

Thanks STEvil

By design Maxforces nVidia cards with variable pStates are supposed to run @ PCI-E Gen 1.x when the card is idle and then switch into PCI-E Gen 2.0 mode when any load is put onto the card, sadly on the X38 chipset there is some sort of "bug" which causes alleged stability issues when a card switches from Gen 1.x to Gen 2.0 mode. So nVidia chose to lock the cards @ Gen 1.x mode regardless of how much load was put onto a card.
If you are not convinced I can post a picture of a GTX 480 running Furmark for more than 5mins yet still locked @ PCI-E 1.x (this was kindly posted by someone who suffers from this bug on a ASUS P5E3 WS Pro (X38) motherboard).
John

Quote:

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Originally Posted by JohnZS

Thanks STEvil


If you are not convinced I can post a picture of a GTX 480 running Furmark for more than 5mins yet still locked @ PCI-E 1.x (this was kindly posted by someone who suffers from this bug on a ASUS P5E3 WS Pro (X38) motherboard).
John

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I am not convinced I chacked 10 games and every time PCI-E changed to 2.0 even with a small load.
This is one of the smallest loads 30% of GPU use
http://a.imageshack.us/img535/3650/crysh.jpg
pci-e change in P3-games do not use this mode
http://a.imageshack.us/img840/5936/pstate.jpg
PCI-E change to 1.0 in P -state 12 idle mode
http://a.imageshack.us/img819/4527/pstate2.jpg

you do not loose performance in games, only i p3 mode--when you play movies and for this you do not need PCI-E 2.0

So show me furmark or any game with pci-e 1.0 on x38/x48/x58, I do not see, only idle and p3 state which in no way interferes of any performance .

The Bug does not occur on X58 and X48, apparently those chipsets are now fully ratified to work by nVidia (I believe there was a driver version which did lock those chipsets out at one point, or some early X58 BIOSes had an issue). Anyway what motherboard are you using?
Here is the proof for you..
http://a.imageshack.us/img840/5519/gtx480fur3k.th.jpg
Thanks to MikeS on the nVidia forums for performing this test :)
John

Intel DX58SO and I never had a problem with PCI-E in 3D mode.

Quote:

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Originally Posted by JohnZS

Thanks Ket :)
What constitutes a bootup issue? The card not being found on POST so leaving you with a lovely beep code? Or system booting with crippled performance (like with the GTX 295 on rare cold boots).
John

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The problem is the monitor signal being dead for no reason at some bootups and on most restarts. Theres no reason why this should happen, it just does in some systems. Best I can figure out is force the mobo BIOS to only use P8 state on boot / restarts, should fix the issue 100%.

Quote:

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Originally Posted by JohnZS

nVidia have responded...



What would your opinions be guys?

John

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Instead of nV doing that get them to simplify things. They need to can the P12 state. Modify the P8 state to run GPU/mem clocks of say 200/300, unlink the P3 state and use it for UVD/DVD/Blueray playback, clocks of 400/1000 should be plenty. Finally use P0 as its always been used - for 3D clocks.

Quote:

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Originally Posted by Maxforces

Intel DX58SO and I never had a problem with PCI-E in 3D mode.

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I bet that the Intel board has an ACPI table in the bios that conforms to the "standard" for ACPI a lot better than many others tend to.

edit

102c is pretty toasty there JohnZS

Thanks Ket
I have relayed this onto nVidia (and credited you for your expertise and knowledge).

Indeed STEvil, I must admit I was concerned when I saw 102C and informed Mike that his GTX 480 was running extremely toasty. For comparisons sake a GTX 295 (Single PCB) in my system runs upto 86-88C after one whole hour of Furmark @ 1920*1200 16XFSAA. I think that is "safe" as during heavy gaming the card never goes over 70C (according to eVGA precision tool).

You are right, I think the DX58BSO had this issue fixed in a BIOS update.

Quote:

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Fixed issue where SMBIOS System Slot structures mismatch for PCIe Express Gen2 slots

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Listed as a fix for July 2009?

Also in May 2009

Quote:

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Set Slot Power to 300W for PCI Express x16 slot

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But then again I know nothing ;)
John

Oh, so its clear for the nV boys aside from the P12 state causing havok in some systems the clock going as low as 50/135 cause problems in Windows as well sometimes. Depending what you are doing, when the card goes as low as 50/135 a Windows message pops up saying aero performance is really bad do you want to disable it etc. Its generally very annoying. Incredibly, performance even on the BIOS setup menu is terrible as well. Never in my life have I had to put up with such slow scrolling and screen lag.

Quote:

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Originally Posted by Ket

Oh, so its clear for the nV boys aside from the P12 state causing havok in some systems the clock going as low as 50/135 cause problems in Windows as well sometimes. Depending what you are doing, when the card goes as low as 50/135 a Windows message pops up saying aero performance is really bad do you want to disable it etc. Its generally very annoying. Incredibly, performance even on the BIOS setup menu is terrible as well. Never in my life have I had to put up with such slow scrolling and screen lag.

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Please post screenshots of it happening.
Do you really think that NF100/104 based VGA can't process text mode @ 50/135MHz?

Quote:

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Originally Posted by JohnZS

The Bug does not occur on X58 and X48, apparently those chipsets are now fully ratified to work by nVidia (I believe there was a driver version which did lock those chipsets out at one point, or some early X58 BIOSes had an issue). Anyway what motherboard are you using?
Here is the proof for you..
http://img840.imageshack.us/i/gtx480fur3k.jpg
Thanks to MikeS on the nVidia forums for performing this test :)
John

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Why the thread still says "PCI-E Gen 2.0 Bug X38/ X48/X58"?

1. Screenshots won't capture the lag :p:
2. In the BIOS setup menu the card isn't running 50/135, if it was, there wouldn't be a problem. The card apparently dynamically downclocks to as low as 13MHz when not in Windows, that certainly would cause lag, even in a BIOS setup menu.

Quote:

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Originally Posted by Ket

1. Screenshots won't capture the lag :p:
2. In the BIOS setup menu the card isn't running 50/135, if it was, there wouldn't be a problem. The card apparently dynamically downclocks to as low as 13MHz when not in Windows, that certainly would cause lag, even in a BIOS setup menu.

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Not lag, balloon tip in Win.
13MHz? There is no performance level with 13MHz core speed.
BTW, my VGA regularly downclocks to 50/135 and runs 2D/flash/movies no problem.

I don't know how to reproduce the win popup so I'll try to remember to get a screenshot with what I'm doing when it next happens. As I said, there doesn't need to be a P-State with those values, they are part of the P12 state where the GPU/memory can adjust themselves it would seem from anywhere between 13/34 and 50/135.

Quote:

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Originally Posted by Ket

I don't know how to reproduce the win popup so I'll try to remember to get a screenshot with what I'm doing when it next happens. As I said, there doesn't need to be a P-State with those values, they are part of the P12 state where the GPU/memory can adjust themselves it would seem from anywhere between 13/34 and 50/135.

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OK, you do that.
You are saying that VGA can set clocks other then preset performance levels? And how do you prove that?
If you prove it, I'll stand corrected, but otherwise it's just a nonsense, as I never seen it happen to anyone else, or had similar experience(s).

Just run nvidia inspector and select the P12 state from the OC side. You will see the apparent clock ranges. You can also use Fermi BIOS Editor to see how some values are actually set to 0MHz. Don't call nonsence on things when you don't have access to all the tools to look at things properly yourself :shakes:

Quote:

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Originally Posted by Ket

Just run nvidia inspector and select the P12 state from the OC side. You will see the apparent clock ranges. You can also use Fermi BIOS Editor to see how some values are actually set to 0MHz. Don't call nonsence on things when you don't have access to all the tools to look at things properly yourself :shakes:

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I have both tools.
When you select P12 and see range from 13 to 101 it doesn't mean that VGA will change clocks by itself. Just click Unlock Min and Unlock Max and you will see range from 0 to 3000MHz for everything. It doesn't mean it will work and for sure doesn't mean that VGA will change speed to anything that is not preset.
And all the boxes in FeBiTor are just BIOS registers to be changed or not, and doesn't represent actual clocks. Newer ATI VGA's might have 0MHz performance level, as it is known that they can go to sleep, but NVidia's can't.

Hi,

Do i have this Nvidia bug???

I am using 182.08 Nvidia driver.

thanks
NBK

If i use the 258.96 Nvidia drive, i appear to be running 1.0 PCI-E.

Quote:

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Originally Posted by NBK

If i use the 258.96 Nvidia drive, i appear to be running 1.0 PCI-E.

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Is it like that right after start, or it drops couple of seconds later?
Check this example on first page, post 21.

Quote:

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Why the thread still says "PCI-E Gen 2.0 Bug X38/ X48/X58"?

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Good question donmarkoni
At the time this thread was posted there was an issue (perhaps related or not?) which meant PCI-E Gen 2.0 did not work on ANY non nForce based motherboard, however this WAS resolved and it may have only been an issue in one, perhaps two 190 series Forceware drivers. This is confirmed with PCI-E Gen 2.0 NOT working on a P5E3 Premium (X48) using a GTX 285 graphics card. And also not working on a Biostar X58A motherboard. However 195 Forcewares and newer appear to not have this bug/issue/lock on the X48/X58 platform, but the X38 is confirmed locked out of Gen 2.0 by nVidia t the moment due to a PCI-E Link pState "bug"
nVidia are considering making changes to their driver code to accommodate for PCI-E Gen 2.0 on X38 based systems and would like our opinions on the matter.
John

Quote:

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Originally Posted by JohnZS

Indeed STEvil, I must admit I was concerned when I saw 102C and informed Mike that his GTX 480 was running extremely toasty. For comparisons sake a GTX 295 (Single PCB) in my system runs upto 86-88C after one whole hour of Furmark @ 1920*1200 16XFSAA. I think that is "safe" as during heavy gaming the card never goes over 70C (according to eVGA precision tool).

You are right, I think the DX58BSO had this issue fixed in a BIOS update.


Listed as a fix for July 2009?

Also in May 2009


But then again I know nothing ;)
John

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If Intel can fix the bug with an ACPI table update then all that needs to be done is to club some engineers at assus/msi/etc and get them to properly validate their ACPI tables...

edit - For the record, ACPI tables have a long history of being horrible quality, just look how badly they're broken under *nix most of the time lol.

Quote:

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Originally Posted by donmarkoni

Is it like that right after start, or it drops couple of seconds later?
Check this example on first page, post 21.

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It does not drop to 1.0 after a couple of minutes...

I have nForce 790i drivers 196.21

GPU Z reports 2.0
CPU Z reports just PCI Express X16

nvidia control panel also reports PCI Express X16 GEN 2.0, so anything wrong here?

is CPU Z suppose to report 2.0 or GEN 2.0 or something like that too?

CPU-Z does not differentiate between PCi-E 1.x or 2.x.... nobody can tell anything is wrong without testing during GPU usage while monitoring. Also the 790i chipset is not an X series chipset, though I guess there is a possibility the problem could exist if nVidia didnt bother to do qualification testing in their own labs with their own chipset..

Quote:

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Originally Posted by JohnZS

Good question donmarkoni
At the time this thread was posted there was an issue (perhaps related or not?) which meant PCI-E Gen 2.0 did not work on ANY non nForce based motherboard, however this WAS resolved and it may have only been an issue in one, perhaps two 190 series Forceware drivers. This is confirmed with PCI-E Gen 2.0 NOT working on a P5E3 Premium (X48) using a GTX 285 graphics card. And also not working on a Biostar X58A motherboard. However 195 Forcewares and newer appear to not have this bug/issue/lock on the X48/X58 platform, but the X38 is confirmed locked out of Gen 2.0 by nVidia t the moment due to a PCI-E Link pState "bug"
nVidia are considering making changes to their driver code to accommodate for PCI-E Gen 2.0 on X38 based systems and would like our opinions on the matter.
John

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As I can't say with certainty, I won't contradict you, but I'm pretty sure I would notice it when I bought DFI X58. It was about a 2-3 months after release and I was using all BIOS'es from the first one on...
I do understand possibility of bug not being fixed for long time on X38/X48, but X58 was (SLI) certified by NVidia... :shrug:
Anyway, it's nice that NVidia is helping solve problem with older chipset.

Quote:

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Originally Posted by NBK

It does not drop to 1.0 after a couple of minutes...

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I'm not sure I understand you... Please take the screenshot right after starting GPU-Z (within the first 15 seconds) and post it.

Quote:

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Originally Posted by donmarkoni

As I can't say with certainty, I won't contradict you, but I'm pretty sure I would notice it when I bought DFI X58. It was about a 2-3 months after release and I was using all BIOS'es from the first one on...
I do understand possibility of bug not being fixed for long time on X38/X48, but X58 was (SLI) certified by NVidia... :shrug:
Anyway, it's nice that NVidia is helping solve problem with older chipset.



I'm not sure I understand you... Please take the screenshot right after starting GPU-Z (within the first 15 seconds) and post it.

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@donmarkoni: Here is the screenshot GPU-Z after about 15 seconds...

Quote:

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Originally Posted by NBK

@donmarkoni: Here is the screenshot GPU-Z after about 15 seconds...

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No problems for you then! :up: As you see, there is remark 2.0 besides 16x. Could be that the BIOS fixes it. It is X38 board with X48's board BIOS, right?

Quote:

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Originally Posted by donmarkoni

No problems for you then! :up: As you see, there is remark 2.0 besides 16x. Could be that the BIOS fixes it. It is X38 board with X48's board BIOS, right?

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Yes, I am using 1001 BIOS for Rampage Formula X48. I am also using an oldl Nvidia driver. IIRC, i think when i was using Maximus Formula's BIOS, i had that PCI-E 1.1 bug.

I tried the most recent Nvidia driver. The PCI-E was reset to 1.x in GPU-Z.

Whew! At least i do not have this issue!

I am also not going to upgrade my video card to the GeForce GTX470 until this issue is resolved...

NBK

FYI Forceware driver 186.18 or older does not have this issue as it does not have the pState feature and X38 chipset block coded into the driver.
I recall Rampage Formula itself does not suffer from the PCI-E Gen 2.0 bug, BUT Maximus Formula flashed to Rampage Formula DOES suffer from the bug/lock.
Install any 190+ series or newer forceware to see for yourself...
John