Sapphire HD3870X2 Low performance

[gOtVoltage]

Im pretty shure i know what your talking about ...I just dont know how to explain A better example about what im talking about..

Example:If i were too..

SLI two GTS512mb's or even GTS1big's you will only get 512mb(57.7) of bandwidth because of 256bit controler and SLI...It defaults to ONE cards memory for both cards regardless...Fact


I dont think this is the case with the 3870x2... Crossfire( I may be wrong) uses all the vram on the x2. unlike SLI. Both cores do not have to share 512mb....Each core uses its own 512mb...GPU1 uses 512mb and GPU2 uses the other 512mb. Both GPU's dont use the same 512mb shared like the GTS in SLI.


This means means the 3870x2 2x256bit should have 57.7 per 512mb..Per GPU..?

3870x2 GPU's use a total of 1gig with (2x256bit controlers )this means 512mb for each core...I Know that i said there is a total of 114gb/s when in crossfire mode at 100% This will hold true if the card uses all 1gig..Im trying to find this out..Ive always thought Unlike the GTS in SLI the 3870x2 uses a seperate 512mb for each GPU .Each GPU always has 512mb at hand...This is where Nvidia would lack in SLI. You can (Only use the Memory from ONE GTS/card) for both Cards/GPU's in SLI .You will not be able to use the Vram on the secondary card..Which means you will only have 57.7 for both GTS cards!...

Well Bandwidth wise Nvidia's Ultra which has 106Gb/s with 768mb would be higher if it had 1gig..On second thought if the 3870x2 used 512mb for Both GPU's =28.8gb/s there is no way it could Run HIGH res and beat the GTX/Ultra . I know GTS 256bit bus can push 1gig but at 57.7. With that inmind the 3870x2 would have to run 512mb per core or all 1gig is combined on one 256bit contoler somehow..It has 2x256bit though!

I really hope im wrong,But i know for fact 2 GTS512mb total in SLI only use 512mb, despite there being 1gig total between two cards..I pretty shure that Crossfire will use the Vram that is on its own card for its own GPU.Crossfire alternates between both cards using the Vram dedicated for each GPU.

Yes we all know GPU-Z is suppose to read 57.7 for each GPU when selected on the 3870x2....Ive been searching for the Info on 3870x2 Crossfire and 1gig vram . I cant believe No one has even brought this point up before..

All ive found is that SLI/CROSSFIRE uses the max Vram of the highest card...
What bugs me is the 3870x2 is ONE CARD with 1gig of ram and 2x256bit controlers.I really need to know if this single card uses the Max ram(all of it) Or only half of it..On a side note Even a GT/GTS with 1gig runs at 57gb/s with a 256bit bus/controler. Rember There are (two 256bit buses on 3870x2) Each GPU' uses thier own 256bit and 512mb ,57.gb/s for each core instead of both using the same 256bit controler...I cant find any documentation that says the 3870x2 only uses 512mb of its 1gig for Crossfire..

It wouldnt make sense to have 1gig on a 3870x2 if you only use 512mb and one 256bit controler to get only 57GB/s now would it.

Thanks

[MadDias]

the hd3870x2 is not a "single" card. it´s in fact two cards on one pcb. it´s the same as if u would have two hd3870 cards in crossfire. that´s why it doesn´t have 1gb vram. the gpus on the card can only take advantage of their 512mb vram connected thru a 256bit mem interface.
ur right that each gpu uses it´s full 512mb on it´s own. they don´t share their vram. that´s why cf-modes like "scissor" are possible, which should be one of the advantages over nvidia´s sli. but it still has to load the same textures to both 512mb framebuffers on each "card".
i don´t see why u want to believe that the memory interfaces add to each other. the 28.8gb/s u saw on one of the screenshots is the bandwidth in 2d-mode with lower clocks than in 3d-full-screen-mode.
i say it again.. bandwidth doesn´t increase with more vram. a 8800ultra wouldn´t have a higher bandwidth with 1gb. my hd2900 has more memory bandwidth and is only a 512mb vram card.

[drunkenmaster]

Just gotta say, thanks for that great flashing guide jpercel!

Did this with my Powercolor X2 last night and it worked a treat!

One thing I did notice though is that both my cards had 64kb BIOS's (according to ATiFlash) but GPU-Z gave me a 44 + 64 BIOS files...

Eitherway, they flashed fine and now my Crysis and UT3 fps problems are gone

Did anyone else have the same issue? from gpu-z i get two files, 43 and 62kb's(i assume thats just space on hdd being slightly different right?) but in dos using atiflash both cores show up as 64kb. Do you just flash the 43kb one to the slave, and the bigger bios to the master core? might try ripping the bios's through dos and see if i get a different result, maybe vista +gpu-z + getting bios isn't the best method.

[C-N]

Did anyone else have the same issue? from gpu-z i get two files, 43 and 62kb's(i assume thats just space on hdd being slightly different right?) but in dos using atiflash both cores show up as 64kb. Do you just flash the 43kb one to the slave, and the bigger bios to the master core? might try ripping the bios's through dos and see if i get a different result, maybe vista +gpu-z + getting bios isn't the best method.

I have a Powercolor 3870x2 & I have flashed it many times. GPU-Z captures the cards BIOS as 43/62k but if you type (atiflash -ai 0) to display the slave cards info it shows as 62k.

I just ignored it first time out & now I just go straight to prompt change path to the bios folder & type in the command & don't worry about it.

CN

[barfastic]

i had the same problem but when i downloaded the 8.3 my card worked GREAT. crysis at 40+FPS at 1680x1050 and 2xAA.

if you ahvent downloaded the newest cat, go get it, and make sure u actually HAVE deleted your previous drivers.

other than that, digg around a bit, the solution is out there.

[zlojack]

Kotz!

Follow these steps to fix the powerplay issue: I wish ati would fix this though because doing this is a pain in the *** and it MAY void your warrenty.

First download GPU-z 1.7
http://downloads.guru3d.com/GPU-Z-0.....html#download

This tool will allow you to extract your video card bioses..That's right your 3870x2 has two bios files!

When you open Gpu-z it will display your cards info. Next to the bios version number is an arrow. Click it and it will extract the first bios file. Save it to your desktop and rename it "backup0" or whatever. At the bottom of the tool it will give you the option of selecting the second card. Click the down arrow and select the second card then extract that bios to the desktop and name it "backup1" or whatever. Double check the two files: one should be like 44kb and the other should be 64kb. Which ever one is the 44kb file is the (slave) card which we will get into later.

Now that you have those files download the atibios editor
http://www.computerbase.de/downloads...i_bios-editor/

Open each file and change the low power 3d clocks. Make them the same as the high power 3d clocks. Also make the voltage the same. Do not change the 2d or startup clocks unless you want to for some reason. Also make sure your changes are the same for each bios ex. dont make one bios file have a low power 3d frequency clock 300mhz and the other have 400mhz. Save both files under different names like "card0" and "card1" because you want to keep your original bios files in case you screw up your flash. Remember "card0" should be like 44kb because its the slave card.

The bios editor you downloaded should contain the ATI Flash utility.
Next you need to make a windows boot disk in order to get into dos. After your boot disk is created make a folder called "boot" and place the "atiflash" application file in that folder along with the backup bios files and the modded bios files.

Get a pen and paper and write down all your file names from the "boot" folder including their sizes.
card0 = 44kb
card1 = 64kb
backup0 = 44kb
backup1 = 64kb
something to that effect.

Write down the following commands in sequence because you may have to reference them in a "blind flash" This occurs when you flash your bios incorrectly and upon a boot the screen goes blank but everything boots normal. Blind flashing involves booting from your boot disk and typing the commands without being able to see them. That is why you need to write everything down and have your backup files.

Next restart the comp and hopefully your boot disk should take you to the dos prompt.

You should see "A:"
(write down the following commands)

Type "cd\boot" then hit "enter"

Type "atiflash -ai 0" then "enter"
(this command will display the info of your slave card. Make sure file size is about 44kb)

Next type "dir" then hit "enter"
(this will list all the files from your floppy disk. Verify that the file names and extensions match what you have written down. Dos my have displayed the file "backup1" as "b~1". If you blind flash you will use "b~1". Also extensions are files that have like .rom or .bin attached to the name. Ex "card0.rom". If you have extensions then use them when flashing.

Type "atiflash -p 0 card0" or "atiflash -p 0 card0.rom" if you have extensions.
(remember card0 is the name of your bios file)

If the flash was done properly you should see at the end something like "10000kb writen" "10000kb verified".

Now for the master card:
Type "atiflash -p 1 card1"

If the flash was done properly you should see at the end something like "10000kb writen" "10000kb verified".

Thats it your done now just reboot and hope you dont need to do a blind flash.

If you have any doubts or if something is different from what I have written, do not proceed, rather write everything down and post it.

Is doing this still necessary? I did it with my first card (great little tutorial BTW), and now that I've got a second, I'm wondering whether to flash the second one too.

Would the procedure be the same? Is it necessary? Or with Cat 8.3 should I just flash back to the stock bios?

[ElAguila]

Thanks for the instructions on the bios flashing. I am getting ready top do mine. I have a question about the gpuz reading though. Is there an issue with gpuz and vista64? Gpuz shows my bandwidth to be 28.8GB/s but everest shows each gpu to have a bandwidth of 56.3GB/s. Which one is correct?

[Nunzi]

Thanks for the instructions on the bios flashing. I am getting ready top do mine. I have a question about the gpuz reading though. Is there an issue with gpuz and vista64? Gpuz shows my bandwidth to be 28.8GB/s but everest shows each gpu to have a bandwidth of 56.3GB/s. Which one is correct?

me 2.......... just checked it out

[MadDias]

when u read the first few posts of this thread u see a screenshot of gpu-z showing exactly those 28.8gb/s. it´s because of the 2d-clocks.
everest is reporting the bandwidth at 3d-clocks.
both is correct.

[Waymon3X6]

what do u guys always have with pcie bandwidth all the time?
his card doesn´t exchange data beween the gpus through pcie.
on the other hand, the card that is bottlenecked by a 8x pcie-lane has yet to be build.
his problem with 3dmark06 is his cpu. @2.6ghz he gets the same cpu score as u intel guys would have with a 1.8ghz c2d.
his score seems right to me.

Thats a low score even for a single 3870, never mind 2. With a C2D he should be hitting around 11k if he had 1 3870 - but he has basically 2.

[ElAguila]

when u read the first few posts of this thread u see a screenshot of gpu-z showing exactly those 28.8gb/s. it´s because of the 2d-clocks.
everest is reporting the bandwidth at 3d-clocks.
both is correct.

Thanks for clearing that up for me.

[mr2sw21]

I just bought the 3870x2 and I got the same issue. Can anyone post how it suppose to looks like in GPU-Z? Please.

[gOtVoltage]

With the newest GPU-Z it will read 28.8gb/s = Normal in 2D mode and the core will be half the normal clocks for GPU 0..and GPU 1 will show full speed...

The Ram should always say 512mb when you click each Core...


The problem is when the card is STUCK/locked in 2d MODE and Not switching it for 3D mode..

256mb of ram and 400mhz cpu on one core or even on both is all youll get..When you have a card stuck in 2D mode(low power state) its like having a single 3870 when this happens...Although it shows Both cores enabled(crossfire)

There is a Known Powerplay Switching problem that has made it happen...The PowerPlay funtion frying and staying in 2dmode or disabling One GPU and memory bank..


3Dmark06 ,,ORB results show...

@2400mhz the 3870x2 should run at 13500+ and thats with a Phenom
@3000mhz it will be 15700/16000+ and that with a Phenom

a Q6600 @2400mhz/3000mhz has a very simalar score!

Most recent GPU-Z...Clicking the lowest/second 3870x2 box,,will show you that secondary GPU is at full speed...gb/s should change when in 3Dmode while enabling AMD GPU tool or gaming.

[mr2sw21]

that's what I have but the second GPU is showing default clock is 411 and memory is 450. I guess I need to use Rivtune to tune it up. but some how when I use 3850 on 3dmark06 my CPU score is 2xxx and once I use 3870x2 my CPU score is 15xx with same stock setting. Strange?

[polar bear]

When I first ran 3DMark06 with my single 3870X2 i got 19284 (Q6600 @ 3.6GHz, DRAM @ 1800 MHz).

Then, after I removed the card and replaced stock heatsink/fan with an EK block, I got only 11416 in 3DMark - with Q6600 OC'd to 4050MHz ?!!

I have no idea whats going on here. Btw I have a 1200W PSU and both 6- and 8-pin plugs connected to the card. Also using latest catalyst 8.3.



Why is there a difference in default and memory clocks between the 2 cores?

EDIT: removed 3DMark06 screenie as I was using different drivers. Thanx cadaveca for pointing this out.

[cadaveca]

different drivers cannot be used as compares. Your problem lies here.

[mr2sw21]

that exactly that I have but I never see my 3dmark06 score get that high highest I got is 10500 something like that with the 3870x2 also the heat came out is very hot but at least keeps the GPU in around 50c I guess that's ok right? So will one rather buy 2 3870 or buy one 3870x2 since 2 3870 is still cheaper and I think will be faster than 1 3870x2? Any suggestion?

[cadaveca]

Yeah i got a suggestion, and don't take this the wrong way...start another thread for your issues. You cannot post so little information about your system and expect an answer. We'd love to help, but cannot with so little info.

[mr2sw21]

good idea

[polar bear]

Auch, didnt notice that, well spotted! Will rerun with both at 8.2 then repost screenshot.

[polar bear]

[polar bear]

ie now using exactly the same settings - same cpu OC, same memory clock, same ATI driver... ie no discernible difference. And still a HUGE disparity between the results.

In particular the SM 2.0 and 3.0 scores are nearly twice as much in one compared to the other.

In comparison, I'm getting 15223 with 2x 8800GTX in SLI with E6600 at 3.6. I would think the 3870X2 should score even higher than this. Something is up with the 11k score

[cadaveca]

E8400 @ 3.6ghz, one 3870x2:

16676

http://service.futuremark.com/compare?3dm06=6023631

E8400 @ 3.6ghz, two 3870x2:

18236

http://service.futuremark.com/compare?3dm06=6023585



Yeah, I'd say something was wrong there...can you try 8.3 hotfix driver for comparison?

[polar bear]

Solved! Turns out I had catalyst AI disabled which resulted in the low score. I had been experimenting with FSX and forgot to turn it back on. Have not completed 3DMark06 yet just realized its already better cause opening of return to proxicon got 120 fps. Will post screenshot and link when it's complete.

So maybe a note to OP to check if his catalyst AI is disabled too...

[polar bear]

http://service.futuremark.com/compare?3dm06=6023743