Posted at www.hardwareasylum.com. Here's the thread. Have fun!:)
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Posted at www.hardwareasylum.com. Here's the thread. Have fun!:)
Details? Why is this better than just changing it through the BIOS? Thanks! :)
Just giving ppl another way to up vdimm using 3.3v rail. It's just the old and trustworthy vdimm mod. With a modded PSU, you can get stable vdimm over the default in BIOS when using 3.3v rail.
There is the jumper trick to make more options available in the BIOS. But what if you forget about that and select a vdimm that's higher than your rail? You can kiss your board goodbye
You can setup the board to use 5v rail, but you get a hot FET that just brings instability.
A few members reported having issues when using the 5v rail. User or not user error, I don't care. Here's the mod and I hope it helps ppl out there.
IMO, the vdimm mod using 3.3v rail will give you cleaner voltage.
Good work on the Vmod bro :toast:
Malves and myself have been thinking, this mod could possibly help people who are experiencing cold boot problems. The problem with cold boots has been found to be the fact that the board feeds the RAM with ~2.6v before the BIOS is loaded. By doing this mod, it should be possible to set the Vdimm that the board boots with, using the variable resistor, so that the voltage the Vdimm regulator gives out is set by the user, and not what the BIOS is being told to give out. You will need to set the voltage in BIOS to the minimum possible (so that the voltage doesn't suddenly rise when the BIOS is loaded), and use the variable resistor to raise the voltage to the required level.
Does anyone want to test this theory?
lmfaoQuote:
Originally Posted by persivore
http://www.xtremesystems.org/forums/...293#post916293
i still say the utt-ch just sucks for high voltage long-term
Please elaborate on this vdimm modification..
1. say you only have 3.3 volts on your 3.3 volt line. This mod will allow you to get up to say – 4.0 volts from that 3.3 source?
2. I just did a sense line mod to my 3.3 I set it to 3.5, and have bios set at 3.3 – this actually gives me a DMM measured 3.38 on the memory. Are you saying that if I set my bios to say 3.6, with only 3.5 set on my 3.3 line, this would fry mobo components? Seems this would simply peak out at 3.5, no matter what you set the bios to above that? Note, that setting it to 3.4 may exceed that actual 3.5 volts that are currently set (i.e. .08 higher than 3.3 setting).
Sounds good. :)Quote:
Originally Posted by Malves
I'm going to stick with the 5V jumper method, but I'm glad someone gave people who want really stable VDIMM a mod, finally. :toast:
1. No.Quote:
Originally Posted by timpanogos
2. I read it would damage the board.
wow, thanks for the safety tip there Malves! I'll be sure and watch that closely if I ever go to set my bios to 3.4. Any idea what a "safe" rail voltage would be above your current/desired vdimm?
p.s.
Also wondering then, if one did have like say 3.7 volts on the rail, and wanted to run at say 3.5 vdimm, with the mobo mod, you may want to set your bios to say 3.6 and then adjust the mod's pot for the desired 3.5 exact?
Like even now, the overvolting of my rail seems to cause .08 volts more than the bios setting of 3.3 to actually be applied. Your mod would/could limit this further to the exact 3.3 -- is this right?
The above assumes the bios controls that chip you are further moding.
No, you always select less than the value you want, and then trim to it.
Yes, with a vdimm mod you have total control over the voltage.
but ... that is what you read could blow the board right ?? (rail less than bios setting) .. For example, say I want 3.4 volts .. so safety says, set your rail to 3.3, set your bios to 3.4 and then tweak the rail until you have 3.4 on your memory.Quote:
No, you always select less than the value you want, and then trim to it.
Sorry for all the bother, just saw your name on the hellfire sense mod thread (and ensuing mess) .. and know by that read, that you know what the heck is up.
Thanks!!
Chad
Malves, will this mod work when on the 5V VDIMM jumper?
I would use this in tandem with the 5V jumper, to fine-tune VDIMM.
As it is, my board overvolts VDIMM by ~0.8V-0.9V, so 3.78V and 3.89V are the only two higher VDIMM selections I can make. I want to test between 3.8-3.85V :p
I didn't test it with 5v rail. I'll do that tomorrow and let you know.:)
so if your 3.3v line is at 3.6, you can select up to 3.5?Quote:
Originally Posted by Malves
Trying to find where I read about board being damaged if selecting vdimm in BIOS > 3.3v rail. Can't find it, thou.:(
Please, you guys have to understand this vdimm mod works just like any other vdimm mod for boards that use a 3.3v rail for RAM. All you have to do is to use the board set at 3.3v and a modded PSU. Just like we used to do.:)
You can use the jumper trick posted in the AMD section with a modded psu. But a vdimm mod will give you total control over voltage adjustments.
Tomorrow I'll be checking the mod with the 5v rail to see if vdimm over 4v is possible for the kamikazes out there.:)
You may have to add a pot to the 1st stage control Malves to get much over 4V... opposite side of the dual amp ;)
Peace :toast:
Interestingly enough, it seems to be the exact same voltage regulation circuit like on the DFI LP NF3. :)
how can I measure vcore and vchipset in that board?
Malves have you or anyone seen the NF3 939 DFI? I want a vio mod for it also.
Nope, haven't seen that board yet, bro. I don't like vio mods, sorry.
Just to add, VTT tracks just fine on this board. VTT check is the top leg on that same mosfet (where you check vdimm) in that pic.:)
Barr3l --- Look here for all V measurement points
Depends... put in 2x512 with >250Mhz Memclock and run Memtest T8 with VTT instrumented bro ;)Quote:
Originally Posted by Malves
Peace :toast:
Hmmm...didn't know that. I don't have a cpu to run that test.:(
"just to add, VTT tracks just fine on this board. Vtt check ..."
"depends ... put in 2x512 with ..."
what language are you guys speaking?
Can you tanslate to gumbie?
what is Vtt? and what does it have to do with vdimm and chipset voltage, and 250memclock with 2X512 and some processor needed?
boy am I lost or what?
Chad
vtt is half of vdimm. its very important and if it gets too high or too low of the vdimm then stuff wount work right. some boards need a vmod to make the vtt right while the dfi nf4 seems to keep it okay by itself. what EMC2 is saying is that if you run 2x512mb ram at >250mhz and then run memtest #8 then the vtt might go off a bit. i think thats what he is sayingQuote:
Originally Posted by timpanogos
Interesting, and I assume the bios has some effect on this tcc as well as vdimm control .. in as much as I have heard some saying that the 5-15/18/23 bios has left them super-pi unstable at previous oc's etc.
What are some of the symptoms that are seen on "other boards" that lead to the vmods? Are there certain ras/cas/drive strength etc. types of settings that corrolated with vtt problems (i.e. some vtt mod allowed for setting x to be tightened to y)
Thanks!!
Chad
"might go off a bit" is putting it mildly :lol:
--- Chad --- Vtt is used by the memory and the CPU as a reference signal to tell when a signal is high or low. It's also used in the termination networks for the signals on the MB to...errrmmm...in "gumbie" as you put it... to make the signals better. What I was telling Malves is that under certain conditions the Vtt fluctuates a lot causing errors. What he was saying is he doesn't have a CPU to put in the MB to check out what I told him.
--- Malves --- Vtt is rock solid stable until certain burst data patterns are used... then it fluctuates quite a bit... enough to cause ~25Mhz OC difference :( It appears to be a load issue, as it's relatively long term fluctuations (you can see them with a DMM). You can run T5 (pretty much T1->T7) and it's rock stable... T8 and it's all over the place during the course of the test. You can pretty much predict when errors will pop up by monitoring where Vtt is. Same thing happens when in Windows... and when running most benchies. Note that both the input rail and the reference to the VTT regulator remain rock solid... it's only the VTT output of the regulator that fluctuates.
Peace :toast:
Interesting. So, maybe a VTT mod could help?:)
Also, I haven't mentioned before, but I knew the LM328 just uses 2nd stage for both 3.3v and 5v. The switch between both should be via jumper, not the stages. So, with that said, I got vdimm up to 4.5v via trimmer, using JP17 @ 2-3.:D
Those that want more control over their vdimm and those that are brave enough for 4+vdimm, this is the mod.:D
wow cool stuff
so malves, think you could make up a vtt mod?
so all we do is put the jp-17 in and we can get higher than 4v with the trimmer in the same place right?
Why don't you like Vio mods?Quote:
Originally Posted by Malves
-sorry for more OT ;)
Malves - ygpm :)
Thanx for the heads up, bro.;)
Well, EMC2 mentioned in his PM, it looks like under load the 1st stage of LM358 limits the 2nd stage to ~4.2v. So, under load, vdimm @ 4.5v may not be possible.
Unfortunately, I don't have the right equipment and not enough of it, too, to test all of this, but I guess EMC2 has been there.
Vio mods don't give you any control over vdimm, that's why.
It's info like this that has me now watching this site/forum closely ... thanks all great info
Why a vdimm mod if you can use the bigtoe mod? the only thing is to fake the 5v jumper. no soldering. Why should i still prefer this mod?
I believe the "bigtoe mod" is to slide the block connector down one row, put it on the 3.3v side and single jumper the exposed top pins from the center to 5V side.
This is the jumper that allows the bios to set voltages over 3.2. However, you are now on teh 3.3 volt rail, and being able to set actual voltages above 3.2 will be based on if that voltage is available on the 3.3v rail. With supplies like the OCZ the supply allows you to tweak this, on others, you'll need to vmod.
However, Malves has warned me that setting the bios higher than what is available on the rail could damage the mobo. So you might want to be careful with the BigToe mod, making sure your rail is over what the bios is going to try and put on your memory. Also be aware that my bios/mobo/etc. seems to overvolt the mem by about 0.08, so I assume you best have your rail overvolted by at least that same amount from what you plan on setting in your bios
I remember reading something about this, but I can't remember where. :mad: So, don't take my word for it. :)Quote:
Originally Posted by timpanogos
the bios will only go up to 3.3v and then you just adjust the rail and nothing more in the bios. there isnt an option for a higher voltage so unless you 3.3v rail is less than 3.3v then there will not be any problems
It really works great on my board. setting my ocz to 3.8v and i gain a stable 3.7vdimm. Works truly great!
are there more mods for the nf4 ultra-d?
Which one? Bigotes'? There's vcore mod, but i don't think anyone will need it.:)Quote:
Originally Posted by Waus-mod
And the vtt?
wow vtt does suck. specs in my sig, i was running 275*8 at 3.6v (bios) and the actualy vdimm was 3.7v the vtt was all over the place. it jumped from 1.83v up to 1.87v! ouch! it was anything but close to stable but the 3.7v was satble although i did see it jump to 3.71v for a second a time or two.
anyway, can we fix the vtt atleast somehow?
I've recorded fluctuations of ~80mV when nominal VTT was 1.455... most of it in the negative (lower V) direction... about 3x what it should be.
Here's some pics from an o'scope... sorry for the graininess... frames from a video capture with a digi-cam :lol: These are taking running T8 of memtest, the large steps are when the test pattern changes between mostly 0 patterns to mostly 1 patterns:
http://xtremesystems.org/forums/atta...id=33199&stc=1
http://xtremesystems.org/forums/atta...id=33200&stc=1
http://xtremesystems.org/forums/atta...id=33201&stc=1
http://xtremesystems.org/forums/atta...id=33202&stc=1
http://xtremesystems.org/forums/atta...id=33203&stc=1
Peace :toast:
EMC2, do you think replacing/adding the "VTT caps" would help with the fluctuations?
quick explination of vio please ... I know you said you did not like/use it, just wondering what it is ..
Thanks
Chad
vio = 3.3v rail of your PSU
Malves... slightly, for helping some with the relatively shorter term fluctuations like the small bumps in the 3rd scope pic that occur before the step change... but not for the longer term changes that start/end at the step points. Note the scale on those pics is 5ms/div... and the larger step changes last for upwards of seconds (as long as the offending pattern is being burst). Basically the VTT is drooping due to the current demand and the internal FETs RdsOn. Can think of 3 fixes... 1 that positively would work... 1 that has a 90%+ chance... and one that is 50/50 (which I'm not willing to sacrifice my MB for).
Peace :toast:
sounds like I did the sio mod that you do not care for. I am interesting in going ahead and doing the op-amp mod that was shown as the topic of this thread. However, I'm still confused, without the sio mod, how can the opamp mod help, on my vx that want 3.3+ volts?
I would be interested in your "droop" mod also .. any info is appreciated ...
Chad
p.s. can you elaborate on why you do not like the sio mod
Just a little update on the Vtt side of things... was looking at it and a few other things with better equipment and got a nice capture of a Vtt step. Did a rough calc on the capacitance needed for this... can't get there from here, it comes out several farads worth :lol: However, I did find that drive strength has an effect on the magnitude of the step, gained some Mhz, along with enough info to base fixes on :D Now to find time and parts ;)
Capture of Vtt step on DFI nF4 - this one occured during transition from an FFFFFFFF to 00000000 based modulo:
[IMG]http://img8.echo.cx/img8/6034/vttvme...notated7hz.png[/IMG]
Peace :toast:
wow, I feel stupid now :(
time to go off to get my 3rd degree, this time as EE so I can understand this stuff.
Maybe I speak in medicalease so I can feel smart.
definatly a big problem. hope you can help us EMC2!
How much does a fancy scope like that run?
Hmm, back on topic, I would love to perform any mods required to fix this problem. Unfortunately the only thing I know how to do is look up chip specs and reduce resistance on the sense leg, which is probably where pretty much everyone else here also hits there limit too; we are all betting on you EMC.
It's easy to understand John... just imagine that Vtt is your blood pressure and an equivalent event would be your BP dropping to 70/40 for a few moments when you first see a really fine bikini bendover due to increased blood demand ;)Quote:
Originally Posted by JNav89GT
--- Craig --- More than I would spend for personal use...
Coming up with fixes is easy... doing one that is affordable and can be done by most is a bikini of a different color :lol: Until then, my suggestion is to use Memtest T8 to fine tune your drive strengths ;)
Peace :toast:
I'm currently running on a sio mod, 3.5 volts. But still planning on doing the op-amp mod.
emc2, am I reading your last scope right ...1.38V *2 = 2.76 vdimm - so it looks like you are using tccd (or other lower voltage mem).
1. Would you expect that vx, at 3.38 vdimm types of voltages will also show as dramatic of load dips?
2. were you lowering or raising drive/data strength to reduce the fluctionations. Any suggestions for vx types of voltages I've been running 8/3 just reduced to 7/2 and running test 8 for the night to see how it acts.
Thanks for the information/work on this
Chad
p.s.
3. when analyzing voltages at this level of detail ... do orange/yellow slots make any difference?
4. exactly what brand/model of memory are you using for this test?
yeh i am kinda wondering too... TCCD pulls more amps. thats why it uses less volts. what ya think?
--- Chad --- Ummm... look at what C2 is labelled as ;) Nominal Vtt is 1.455 for that test run... and yes, for that test I was using TCCD.
1) Yes
2) This weekend I'll be back on high volt mem, let you know then regarding #s. From what I've seen to date, lower drive strength (based on info about which way the numbers run on DFI) lessens magnitude of the drop... but too far of a drop and you loose Mhz from edge rates slowing down... it's a balancing act with stock Vtt config. Oh... and think about what kind of memory needs higher drive strength ;)
--- Malves --- based on some other info I uncovered today, this board definitely could benefit from better high frequency decoupling on Vmem and Vtt...
Peace :toast:
ps :p:
3) Not as far as this Vtt issue goes...
4) I'll post that elsewhere later ;)
Does anyone want me to try to design a fix for the Vtt droop problem?
Your 100% right.. I cant find where I read it either..Quote:
Originally Posted by Malves
But I think it was one of the OCZ guys that said if your using the BigToe mod and raise the vdimm past what your 3.3v rail is set to it will cause major problems and might damage the mobo..
on vx, drive=7, data=2 tested well over night - #8 no errors (I was 8/3 and was getting about 5 #8 errors in a 6 hour period)
Waiting your PM with more details.:DQuote:
Originally Posted by EMC2
Plz do.Quote:
Originally Posted by persivore
What more mods are there for this board, if any at all ?
but the highest option in the bios is 3.3v when using the bigtoe mod :stick:Quote:
Originally Posted by THunDA
Nope, I have 4V avalible. I have also used the 4V option while running off of the 3.3 line just to figure out how much voltage is lost from the 3.3 line to the memory, my board is undamaged and my 3.3 line was only at 3.8V. (Just if you are wondering, it's about .2V less than the 3.3 line)
Well... after another round of the Java dance I found that the Vtt issue is a bit more Xtreme than I thought...
Ran a little Spi1M and saw this:
http://img146.imageshack.us/img146/9...gspi32m4cr.png
Then during the initial ramp-up of OCCT, I saw this, about same magnitude as the Memtest T8 drops, but shorter duration (like the Spi1M dips too):
http://img8.imageshack.us/img8/7164/...cctdips5lo.png
Then this is what showed up just as OCCT failed:
http://img146.imageshack.us/img146/7984/occtdip18sn.png
After giving it another go I got this "beauty" after about 5 mins:
http://img146.imageshack.us/img146/4841/occtdip21ek.png
Funny part... this was at sub-standard clocks speeds :lol:
Notice the captures regarding Vtt during OCCT failures are much worse than the MemTest8 ones. Those are about a 17% deviation from what Vtt should be. The part used is rated for 3% regulation. Hmmmmmmmm.......
Those "OC's like a formula 1 car today, won't run at stock next day" comments are starting to make sense...
Oh well, it's Java time :toast:
opps i guess there is a higher option, sorry my bad :rolleyes:Quote:
Originally Posted by craig588
i tried having my 3.3v rail at 3.87v and set the bios to 3.7v and i got 3.7v but the fluctation was HORRIBLE. the vdimm went down to 3.56v in memtest #5 :( this is on a OCZ Powerstream 600watt...it didnt fluctuate though when i have it at 3.8v and set in bios to 3.6v. i saw .1v fluctuation but thats about standard with the crappy circuitry
-----------
@ EMC2
-----------
WOW! its sad that the vtt sucks that bad. thats just amazing how much it drops in OCCT! hmmmm and a cure would be------ :slapass:
Great findings, actually, not so great findings.
A question, Vtt where is it connected to on the CPU and RAM (a pin number would be nice)? I want to read on it.
I'm guessing it is pin 1 of the DIMM, otherwise known as Vref (not to be confused with your Vref indicated in your measuring points). Am I correct?
Well, if someone could point me in the right direction...
What I don't understand, if it is 'just a reference' for the CPU/RAM to 'know' what is a logic 0 or 1, what is loading it so heavily? What is the expected current draw from the VTT source?
You can pick either leg circled in yellow, for VTT reading.
pic doesnt show up....no access permissionQuote:
Originally Posted by Malves
did some intense re-tunes the last few days running on the 623-2 bios.
I'm superpi, memtest, 3dmark05, 3dmark03, 3dmark2001, aquamark3d, S&M (long), OCCT and Prime95 stable --- at stock 200*13 1.5.2.2.5 (all others tight)-- I've also got an alternate set of loose timings which also pass all benches -- 200*13 2.3.3.10 (all others loose)
I'm 240*12 1.5.2.2.5 stable for all of the above -- except OCCT/Prime95 and S&M (cpu ok, mem fails 2nd test)
Same for 240*12 2.3.3.10, 250*11 1.5.2.2.5 and 250*11 2.3.3.10
I tried many things to get prime95 stable at the OC's to no avail!!
After seeing your OCCT scoped vtt - I'll bet prime95 does the same thing!!
If you experts get/have any mod's please pm me, I will try a mod.
Chad
p.s.
you can see my exact settings for these benches here
http://www.dfi-street.com/forum/show...&postcount=116
p.s.s sorry about the dumb comment on the pm me ... just willing to try something, even if it's not ready to publish.... like everyone else here ...
lol we all want a mod. havent you read the thread? if they pm you one, we cant see it :p
Good catch bunky.
Not great news, but a good reason why higher than 3.4V makes not improvemnt beyond 250Mhz on my 2 DFI SLI boards with either UTT-CH or UTT-BH or OLD-BH5. If vtt is falling apart above a certain point, sheesh.
Esp points out why the New-BH (ValueVX) were having Test #8 errors with 1T _and_ bankinterleave enabled.
Simple experiment to generate further data. Anyone with a OCZ booster...which drives Vtt/Vref as well as Vdimm and might take up the slack and provide stable Vtt. Checking the voltages/stability with the booster installed would give as more data points.
Guess we'll have to collaberate on a DFI NF4 Vtt project, like we did for the NF7-S last year.
THINKING CAPS ON :cool:
I have a new booster, but no o-scope - willing to mail it off to emc2 for this test
p.s. I'll go tear down my beautiful overclock and stick the booster in to see if I can get a ottc pass at 250*11 -- report back later
Chad
VTT does not need a mod. It needs a fix. It tracks vdimm, but really bad.
Picture in my previous post above has been fixed.
Thats what I mean Malves. The booster will over-ride the Vtt from the NF4 regulator as it is also a regulator. So hopefully it will provide enough extra current to keep Vtt stable. The result should be a high stable overclock.
So Vdimm stays rock solid through all this, just Vtt gets the shaft?
EDIT: Never mind about below, found it in the AMD datasheet - I should've looked before asking ;-)
Malves, I would like to know what VTT is connecting to, i.e. to which pin on the processor, to which pin on the DIMM slot. Got the pin, I got the details to look things up on.
From a technical point of view I want to read about how and where VTT is used, and looking at datasheets without knowing that, well, is like looking for a needle in a haystack.
Thanks
what about changing out the vtt regulation ic with a better quality one? or adding caps to help stabilize the signal.
EMC said it would take a few farads of capacitence to fix the fluxuations so extra capacitors are a no.
560pF if I remember right. Should give you an extra 5mhz in o/c. Too much hassle for so little gain.
What is the Vtt regulator using for gate drive? If it's 3.3V (with the jumper in standard position) and 3.3 gets pulled down momentarily or gets noisy, it could drop below Vin briefly. The Vdimm reg might ignore it - this one might not. Just a maybe.
sluggo
this problem possible cold be caused by autooscilation in the integrated circuit,wath about trying adicional eletrolitic capacitors in the input and the output from the regulator.
something like this, or am I way off?Quote:
Originally Posted by Malves
http://www.mouser.com/index.cfm?hand..._pcodeid=58114
I'm a bit busy atm to work on a fix for Vtt atm. I should be able to get it done by the end of next week. If anyone wants to work on it instead of me doing it, feel free to do so :).
What I have in mind is to use an opamp between the reference voltage pin on the Vtt regulator and the voltage divider which is used to make Vtt follow Vdimm, and use the opamp to provide feedback to correct the voltage. This will involve lifting one of the pins of the Vtt regulator off the board, however.
Piece of cake.:D:p:;)Quote:
Originally Posted by persivore
Quote:
Originally Posted by dippyskoodlez
Yup, but size 0603. According to EMC2. :)
Lifting a leg is easy, lifting the whole thing would be hard.
Another thing, that seems like a very small capacitance, I have caps rated for thousands of microfarads in a drawer right next to me. Why can't I just use them? I thought I saw multiple farads somewhere which would have been pointless to try to reach, but 560 picofarads is really easy to reach.
can someone post an image with the exat points to soldering the 560pf capacitor?
Normally pf caps are used to filter noise.
Maybe this has been posted before, nice software I came across:
http://www.kemet.com/page/spicesoft
It shows a graph of impedance vs frequency for your selected capacitor.
Select your Chip Type/dielectric for your capacitor and it will show you a graph of impedance vs frequency, a 560pf COG 0603 has its lowest impedance at approx 166MHz. It's a nice toy if you want to pick a cap for a specific frequency. And an 0805 of the same part shows the lowest impedance at 190MHz.
--- stealth17 ---
Go read the 2nd page of my post on the Zippy/PCPnC fix thread for why you see the fluctuations you do with those settings ;)
--- OzSnoal ---
Vtt and Vref are two different signals, depending on where you look at them.
Vref - used for what it's name implies, a reference signal to determine the mid-point of the memory signals. It's an input to the Vtt regulator and is shown in the scope pics.
Vtt - this is the signal termination voltage used to supply the termination networks on the signal lines to/from the memory. If you look at your MB, you'll see nice long rows of termination networks. The loading occurs as a result of the current through these termination networks to the memory signals.
If you want to read information on what it's all about, go look at design guides from memory manufacturer's...
For where to look at the signals in general, they are shown in this post of mine: http://xtremesystems.org/forums/show...1&postcount=10
--- uwackme ---
bunky? :rofl: Yes peaches :p: Vdimm stays rock stable... look at the scope pics again, it's all there ;)
--- Malves (and all) ---
The 560pF caps are for the main frequency components of the noise that is prevalent on Vtt and Vmem - they are NOT for the problem shown above in the scope pics and being discussed. And just one won't help ...
--- sluggo ---
The regulator is using Vmem for both it's input source and it's gate drive... the point instrumented in the pics for all 3 signals is at the Vtt regulator. It is not an input signal droop issue.
--- Portugal ---
One possibility... and it may be being set off by transients... work in progress ;)
--- persivore ---
That is actually one of the possibilities I mentioned to Malves... but to be done right need a small PCB or protoboard. All connections can be made at the Vtt regulator btw ;)
If it is a pure load issue, you could possibly parallel another regulator... would require a small HS and good soldering...
Or another alternative is replacing the existing regulator with a different circuit :hehe:
--- everyone ---
Patience :p:
Peace :toast:
ps. Oz - set it to NPO dielectric and 25V rating... it's 300Mhz centered for an 0603... an 0805 will have a lower frequency center than an 0603 due to the packages higher inductance ;) And I use AVX caps... hate kemet :p:
what thread?Quote:
Originally Posted by EMC2
http://www.xtremesystems.org/forums/...earchid=662302
The sticky... Zippy and 850SSI ;)
it didnt help :(Quote:
Originally Posted by EMC2
vtt is still everywhere
Okay, so assuming this part (the 9173A) is used successfully on other motherboards, then this is either a bad lot of parts or a bad implementation/layout on the DFI boards. If it's a bad lot of parts then mod results may be unpredictable. If it's a bad layout (my choice), it's usually because they've got the bypass caps too far from the part. Wish I could help but I can''t put my board on the bench right now :(
sluggo
*edit* Sorry - I'm jumping to conclusions here. Obviously, there's many more things that it COULD be, and I'm just shooting from the hip.
i know this is a tiny bit off topic but not really.
http://img67.imageshack.us/img67/494...k7fv4io.th.png
look at the position of the jumpers i put in that pic. they are the big black squares. notice there isnt one on row B. here is my thinking:
i was doing some testing with no dimms and power ac off, then switch it on and measure the dimm voltage. with rob B jumper on 1->2 i get 2.4v something. with it in 2->3 i get 2.75v, higher than in the other side. if the vdimm controll is messed up, its obvious you will have voltage to the dimms as both pins (1,3) feed from the 5vsb rail. so i was thinking, what if you dont put a jumper there at all and connect the regular 5v rail to B2 (the blue block)? it wouldnt get voltage untill the mobo is acutally on, thus bypass caps are not charged.
i tried the cold boot find steps with no jumper on the B block and i didnt get any voltage to the dimms with the ac power on.
what do you guys think?
memtest #8 loop , fx-57 , 300 * 9 , gskill 512mb tccd * 2 , 2.87V mem , 1T
Scope Channel 1 : Pin5 in RT9173A VTT regulator
Scope Channel 2 : VTT rail behind DRAM slot
Scope Bandwidth 20mhz
http://oskarwu.myweb.hinet.net/1.mpg
http://oskarwu.myweb.hinet.net/TEK00000.gif
http://oskarwu.myweb.hinet.net/TEK00001.gif
http://oskarwu.myweb.hinet.net/TEK00002.gif
http://oskarwu.myweb.hinet.net/TEK00003.gif
God just entered the building.
Oskar, I've always been able to tweak memtest #5 and #8 to pass ok ... it's OCCT and Prime95 that I could never get to pass.
Please test/provide shots with OCCT running so we are looking at the same thing as emc2.
I'd also be very interested in seeing prime95 shots.
try right off with like 250*11 @2-2-2-8 on some vx type memory for your run, and capture the time frame right were it fails.
Chad
p.s.
I've been working hard to make the dfi oc database, I was stuck at stock (could not prime) until I put the ocz booster in - you can look here for detailed settings/benchmark screens.
going for a Johnnylee 24 hour run to to be able to post here ....
http://www.dfi-street.com/forum/show...782#post152782
Hi Oskar :D
Winnie @ 9x295
Memory TCCD on BP0815 PCB, 512MB per stick,
running @ 295Mhz, 2.5-3-6-3-9-12-2-2-2-3-4708, 1T, 2.91V
BIOS 510-3fixed, DDS=3 ,DS=7 ,Tref=4708, Interleave ON, 256 Idle cycle count
Scope Channel 1 : Pin5, RT9173A VTT regulator
Scope Channel 2 : Pin3, RT9173A VTT regulator
Scope Bandwidth Limit set to 20mhz
Here's MemTest8 with ONE 512MB DIMM - Vtt as it should be ;)
http://img301.imageshack.us/img301/3...by512mb8jw.png
Here's MemTest8 with 2x512MB DIMM, TCCD, BP0815 PCB - considerable change due to load (>6x) :( I see higher than you... RT9173A lot difs or CPU?
http://img301.imageshack.us/img301/4...by512mb8pt.png
Here's what you get from a dynamic load change in windows, Windows MemTest, much worse:
http://img301.imageshack.us/img301/2...eststop0hi.png
Here's one from during OCCT, again, bad stuff:
http://img301.imageshack.us/img301/2875/occtstop1ew.png
I have more pics from the session (including equipment) and AVI videos of the captures (low quality, but hey). However, I need either 150MB of web space or an FTP site at DFI to upload them to if you want to see them.
Peace :toast:
--- Stealth ---
You only have voltage on the DIMMs with AC ON and MB OFF until you boot up one time. After that, when you shut down (MB OFF) the power is removed from the DIMM circuits. The moral is, don't change DIMMs with the Vmem power LED on ;) Oh... and I think this would be better discussed in the PCPnC/Zippy Fix thread :D
Back to the topic at hand...
Ooooooops... forgot another case/data point from Friday...
Same setup as above, but during windows boot-up...
W2K, just after initial screen with scrolling bar at bottom, when the video gets switched over to the desktop resolution (going from VGA to 1280x1024) and video memory loaded (video is momentarily blanked during the switch) you get something a tad worse than the OCCT and Memtest screens above.
The worst case will be all 0/all 1/transitient from all 0/1 to all 1/0 ... The minimal RTT total equivalent resistance in dual channel mode will be around 0.7 OHM ... If the VTT is set as 1.45V , maximum IL in both sink/source mode will be around 2A ... Still within the range of the spec of RT9173A ... RT9173A can control the VTT output within 2% of variation if the IL from -3A to 3A or so ... What you measured should not be a typical result from the design spec ...
I agree... based on the spec for the RT9173A it should not change that much if max load current is 2A. If it is 2A then... bad batch of RT9173A's? Or maybe because VCtrl = Vin instead of VCtrl > Vin. The spec'd output variation is with Vctrl=3.3V, Vin=2.5V.
Note: Not a temp issue either... 120mm fan over DIMMs and covering Vtt/Vmem regulator area... Vtt regulator is cool to the touch.
hey, i just found this thread. Whow...
I am having the same issue that i can run memtest #5 and #8 for hours.....but i cr*p out with OCCT in Windows in 10 seconds at a certain, given dimm.
I used to run my TCCD at 2.9V....and (dont ask me why)....there is an issue with either )the board )PSU )memory ...that my sticks now need MORE and mroe voltage otherwise i cant be stable in OCCT at all.
2.9V is now a total no go so is 3.0V ...i need to push my TCCD (week 37) with 3.1V so i can get stable in OCCT ! (yes, TCCD !!!)
It looks you guys are sitting on the source of MOST instability problems in windows/OCCT....looking at that readings makes me shudder !
I hope you can come up with a solution ! Great reads and insights here !!!