SLI Problem same card = no SLI?

[ridgeback]

Hi,

Recently built a PC aorund the DFI SLI board with a 256MB Leadtek WinFast PX6800TDH (vanilla 6800 in otherwords). In the manual for the DFI it states that to use SLI you need change the jumpers on the board, plus use two identical brand/model cards. This week I picked up another Leadtek card, exact same model and spec, inserted card but ...no-SLI.

Pulled the cards out and scanned all over them. both appear to work and id in the O/S, but no SLI. The PCB's have the same codes, LR2A04 PCB Rev: A, the same stickers: WinFast 256MB PX6800 TDH, warranty stickers both begin L412010.

There are only two differences. One, on the PCIe connector, one card has the letters H / F on it (top/bottom), the other card has U/W.

Then what must be the big difference. atop the PCB's the only other difference is the revision number. The original card is Rev. A1, the new card, Rev. A2.

Surely SLI cannot be That strict???? I mean, I've ordered two of the same card before from the same store when building PC's (not SLI) and noticed they are not the same revision. I am simply astounded if this is the case ...that and gutted!

Anybody else heard/encountered this? Is there a work-around anyone can suggest? I am seriously wishing that I'd had the funds to have gone for the GT, but the costs were much more at the time and I was trying to 'be good and budget'. Alone, the 6800 vanilla doesn't bench that much better than my 9800Pro in my old rig and that's despite having an A64 and 1GB PC4000 rather than the XP2500 and 512MB PC3200. Very depressing.

 

[d2arcturus]

Did you connect the cards with the little SLI connector that came with the board?

http://www.overclockzone.com/spin9/review/mainboard/msi/k8n_diamond/IMG_8336.JPG

 

[Topweasel]

Your problem is different Bios on each card. You can use a tool (don't know ask someone else) to rip the newer bios from the new card and flash the other one to its level. Nvidia stated that their next driver revision is going to included support for different bioses and different manufacturers.

 

[ridgeback]

Thanks.

Sorry yes, I did use the SLI bridge PCB that came with the board. I looked at this in detail too, as it seems it may require correct orientation (inside of the PCB has labels J1 and J2) which is not mentioned in the Manual. Either way, shut down and re-started having tried both ways.

I gathered there must be a different BIOS issue there. However, I tried running the info section on 3DMark05 to see and it didn't highlight any differences. Must be a tool that does, maybe download RivaTuner. I guessed their must be a BIOS tool somewhere, just a question of where to find it??? Hopefully they will either fix this issue, or I'll find a tool. This build has been nothing but problems ...though I guess we are all due one every now and again.

 

[bob4432]

a friend of mine had this same problem, 2 "identical" cards, but no sli. upon close examination, 1 card was missing 1 part on the pcb that the othe card had. he took it back and found a card that had the "missing" part and it worked fine. sli seems to be very picky...

 

[ridgeback]

Right have it all sorted! Thought I'd share the process but be warned it is a long one!

Fix - Matching non-identical 'identical' PCIe cards to run SLI

* Set mainboard jumpers to SLI and insert both cards but with the SLI bridge Removed.

* Windows should still boot with display, just no SLI.

* Make a DOS Bootdisk in Windows on a Floppy, or if you have ability to boot to memorystick etc. create a bootable media as appropriate.

* Onto this media, copy the files for nvflash 5.13. These are "CWSDPMI.EXE" and "NVFLASH.EXE" respectively.

* Restart the machine and change the BIOs boot order to only boot from this media you have created.

* Re-boot.

Note: For this example I have two identical Leadtek WinFast PX6800TDH cards that are identical according to the PCB's except for the revision stamp on the top side of the card at the opposite end to the SLI connector. These two cards are RevA1 and RevA2 respectively.

* At the prompt, type "nvflash -b a:\reva1.rom" where "reva1.rom" is the rom name for this card's backup and a:\ is pointing to in this case a floppy.

* As both cards are installed, the utility will run and ask which card you wish to backup, on a DFI SLI board, the choices are Adaptor 0 and adaptor 1. 0 is primary, 1 secondary.

* nvflash will right a rom image of whichever card you chose.

* Now type "nvflash -k a:\reva1.rom" to compare the BIOS backup with the backed-up cards active BIOS.

* Again you will be prompted for which card, select the same card. If the backup is both identical and intact, it should match and furnush you with the details of the BIOS, e.g. "Current - 05.41.02.17.00", "compare with - 05.41.02.17.00"

* Repeat these steps to back-up (reva2.rom) and then check for the next adaptor, in this case adaptor 1.

* To test, you can now run the compare commands against the wrong adaptors without issue, it will simply inform of:

"ERROR: Mismatch at offset 2" this is where the SLI is not working in Windows. E.g. compare the A1 revision card to the A2 revision card's BIOS produces the error with these details:

"Current - 05.41.02.17.00", "compare with - 05.41.02.17.68".

You can see that they are almost identical apart from the '00' now being '68'.

* Shut down the PC, and re-set the Jumpers to non-SLI mode (a pain!).

* Then, remove the newer card.

* Re-start, and boot to DOS again. Run the compare code "nvflash -k a:\reva2.rom" against the revA1 card logged as Adaptor 0, it should obviously fail again ...unnecessary step really but just to be sure!

Note: If you've backed-up both BIOS's you have fall-backs to restore either card to its original state, or to try SLI working with both cards running each BIOS (Old/new).

I haven't tried this as it worked first time, but I presume you may be able to take two "identical" cards from different manufacturers that use the reference design, and flash them with the same BIOS so they have not only the same version but also manufacturer ID assigned. This is at your own risk though and probably best not tried with makes like Asus, Gainward etc. that tend to employ proprietry designs! In short, you can override the
protection, accept the warnings then 'suck it and see'

* Now, overwrite the older BIOS with the new one (or new with old if you want). Type "nvflash -5 -6 -g a:\reva2.rom" and follow the prompts. These switches preserve the softstraps but over-write the PCIe ID safeguards (allow firmware and adaptor PCI device ID mismatch and allow subsystem ID mismatch)

* Shut down, replace the Jumpers to SLI and install the SLI Bridge this time with the second card

* Re-boot then type "nvflash -a" to list all adaptors

* If anything has gone wrong, flash back to orig.rom using the steps outlined to make the changes, only referring back to the backup "reva1.rom".

* Re-boot without the bootable nvflash media, re-set BIOS boot order and load windows.

* You may either need to re-install the video driver, or encounter Windows re-detecting the 'new hardware' which will entail a re-boot.

* Re-boot one last time, check the display properties then SLI multi-GPU should be enabled!

 

[ryanv12]

wow...you figured that out...hardcore, man.

 

[d2arcturus]

Good job man :thumbsup:, enjoy the SLI goodness to come.