Topic: 7xGPU + Windows // modding AMD video driver is the answer - page 13. (Read 71731 times)

I can use the 4x7990 without lbr mod on several motherboards.

But I cannot use 6x390 on the Asrock H61 Probtc boards. Anybody with any luck on that MB?

Win8.1 and  AMD 16.3 drivers ? or is it a must the 15.7 drivers ? in order to work 4x 7990 Gpus

It is very ordinary riser cable. Two with molex +12V power, two without. The 7990 draw very little from the PCIE and I undervolt and underclock them.

@Zitdadast what kind of pcie risers do you use ?
Any link ?

Yes. I have the Win8.1 and  AMD 15.7 driver and I have 4x7990 on the Asus P8Z77-M Pro motherboard, no mod is required.

Because Windows 10 works with 8x290 out of the box.
On 7/8/8.1 only 7x290 worked with the mod applied.

Thanks for your help, I will try your tips
Btw why Windows 10 ? In Windows 8.1 do i have any chance to have 4x7990= 8GPUs ?

4x7990 max. afaik. That is 8xGPU. Use Windows 10.

As for x16_x16 vs x16_x1.. well.. I dunno. I've tried x16_x16 risers also and they did work. However I've never used x16_x16 in production, that is running rigs 24/365. Only x16_x1.

Anyway, your issues.. seem weird. Technically there is no difference between usb risers and common x16_x1 powered risers.
However, I've seen vide cards which just refuse to work with any riser.

And.. since I can't get hands on your system.. sadly I can't help.. But do try setting pcie to 1.1 speed(I can't find it in the manual.. maybe it does not exist?), setting primary GPU to one of the x16 slots and plug GPU there. Only one GPU.

Play with those -

Manual, page 47
Init Display First
Specifies the first initiation of the monitor display from the PCI Express or PCI graphics cards .
PCIe 1 Slot Sets the graphics card on the PCIEX16_1 slot as the first display. (Default)
PCIe 2 Slot Sets the graphics card on the PCIEX16_2 slot as the first display.
PCIe 3 Slot Sets the graphics card on the PCIEX4_1slot as the first display.
PCIe 4 Slot Sets the graphics card on the PCIEX4_2 slot as the first display.

Manual, page 45
Full Screen LOGO Show
Allows you to determine whether to display the GIGABYTE Logo at system startup. Disabled skips the
GIGABYTE Logo when the system starts up. (Default: Enabled)

Manual, page 45
Display Boot Option Control
Allows you to select whether to enable the UEFI or legacy option ROM for the graphics controller.
Disabled Disables option ROM.
Legacy Only Enables legacy option ROM only. (Default)
UEFI Only Enables UEFI option ROM only.
Legacy First Enables legacy option ROM first.
UEFI First Enables UEFI option ROM first.

Hm. Looks that way. Or m$ screwed somewhere ; )
Also, you can find driver version using GPU-Z.
GPU-Z "driver version" corresponds to m$ "Version" and to "DriverVer" in .inf file.

I searched the "AMD R9 390", there is no Win 8.1 drivers. Does it mean we cannot get auto update for 390 in Win 8.1?

http://catalog.update.microsoft.com/v7/site/Search.aspx?q=amd%20r9%20390

@Lbr thanks for the help,,,
Mine is revision 5 the mobo ....
I am waiting some x16_x16 powered risers(flat) from ebay the ones with the blue tape ..

-Do you think they will work or i will have to order the ones that you say (x16_x1 powered risers(flat)) ?
- I want to attach 5 or 6  HD7990 i don't know if i can put so many ...

http://catalog.update.microsoft.com/v7/site/Search.aspx?q=amd%20r9%20290

I'm running 1x7950+5x290 on 990fxa-ud3 R3 right now. I was running 6x290 on it also.
Using x16_x1 powered risers(flat). Without PCIe precence short(A1, B17).
Motherboard is picky about primary GPU - the monitor must be attached to the GPU selected in BIOS.
Also to run headless "full screen logo show" must be enabled in BIOS.

And try setting PCIe to 1.1 speed in BIOS.

In the Windows 8/8.1, the auto update driver, which version is that? Is that version good for Ethereum mining?

I have a gigabyte GA-990FXA-UD3 R5 and is running 2 graphic cards on the board in the pcies x16
The mobo has 4 pcies 16x and 2 pcies x1 ...

When i try to add a usb x1 pcie riser the pc does not work ,,, Windows 8.1 recognize the usb X1 to X16 pcie riser but when you plug a gpu on the riser is not working ,,,, also i tried the trick with the cable A1, B17 ... https://bitcointalk.org/index.php?topic=36061.120 and it got stuck the bios and i had to remove the mobo battery for a while ..

Also when I place the usb X1 riser in a motherboard X16 pcie slot again is not working .....
should i try risers with flat cable ? 16x to 16x and 1x to 16x ?

If you have any suggestion let me know ....

I actually tried that twice, with DDU and everything but for some reason that 15.12 can't work. Don't know why.

If we can have 12 GPU working on the Asrock H61/81 system, that would be excellent. If we can install 6x7990 and make it working.

No clue about nVidia, however - https://devtalk.nvidia.com/default/topic/738070/cuda-setup-and-installation/8x-gpu-gtx-issue-under-windows/post/4208565/#4208565
So there may be issues as well.

As for AMD, in 8/8.1 if you installed Microsoft driver(from auto-update) not AMD(downloaded from amd.com etc) - then more cards were working. Basically M$ driver had my mod embedded ; ) But not all of it. In w10.. imo a lot of things have changed. Also AMD removed Catalyst.
Actually, the whole idea of the mod grew from this post - https://bitcointalksearch.org/topic/m.2536323

Anyway, there were no limits hardcoded or stuff like this - just the driver and it's configuration were not tested properly on 6+ GPU setups.
Imo since nVidia launched Grid, they did test on 'a lot of GPUs' systems and AMD didn't.

Well.. I've tested 15.12 on 1x7950 + 5x290 and it does work for me.
Maybe you want to try cleanup first - removing driver completely etc.

Is there still 8 GPU limit for AMD cards? I think there is no limit on nVidia cards. So it is in the design of the AMD driver?