PC Drivers & Software

[FatePhenom]

Greetings,

I am Matthew, once a hardcore gamer, currently an engineer (civil/mechanical) and a 3D modeler, running FEA/FEM etc. as well as casually gaming.

So I have the following system:

CPU: AMD Ryzen Threadripper 1950X
Mobo: MSI SLI Plus x399
Memory: Corsair DDR4 2667 4x32GB (128GB total)
GPU1: AMD Radeon Pro Duo (Polaris) (2GPUs card)
GPU2: AMD Radeon Pro Duo (Polaris) (2GPUs card)
SSD: NVMe intel 670P
OS: Windows 10 Pro X64
Drivers: tried multiple

The problem is as follows, device manager always shows 4 GPUs, Task Manager always shows 4 GPUs, AMD PRO software almost always shows 4 GPUs.

The problem starts when trying to enable crossfire alltogether. One GPU is "left behind" with zero activity and AMD software shows it as "Discrete" instead of "Linked" like the rest.

So, at this point, I've tried a lot of solutions, formatting the drive, clean installing older drivers (every driver up to 2 years older), even windows 11 and Server.

Bios is the latest beta version that MSI offers for my specific board.

On the bios. I've tried: "enable 4G decoding", setting both PCIE ports to "x16" mode, and also "Gen 3.0" option.

What I've also tried: Running each card "alone", which, when I do, they run flawlessly. I've also tried swapping them all together, changing the upper card to bottom slot and vice-versa.

Can't figure out why one of the four GPUs remains as "discrete" and is being "left out".

Any help/advice/suggestion would be highly appreciated. At this point. I am desperate for a solution.

I am also attaching some pictures of GPU-Z as well as AMD Radeon PRO software, showing one GPU as "Discrete".

GPU-Z 3GPUs enabledAMD RADEON PRO DiscreteAMD RADEON PRO Linked

[elstaci]

AMD Moderator for Professional GPU card might be able to assist you with your issue.

@fsadough 

[fsadough]

1. Where exactly do you enable Crossfire?
2. Why do you need Crossfire? For which application?

[FatePhenom]

So far, I tried enabling Crossfire through the Radeon PRO GUI/App.

I don't know of any other way of enabling or force enabling Crossfire.

What I am trying to do here is make sure all cards are linked together, so as to make sure, all GPUs would be readily available when called, instead of "idling" at a parked state. In order to do this, I am pretty sure all cards must be linked together, instead of idling, for example.

Typical programs I use, Autocad, Solidworks, Inventor, ANSYS, Nastran, and various games, mostly online games.

Long story short, I can't link all GPUs together, just 3 at a time at most, while, inserting each card alone, easily lets me enable "crossfire" mode (so 2 GPUs in a single card) without any issues, so I am pretty sure, the hardware is not the case here.

For PSU, I have a 1500w unit, which I am pretty sure can handle with ease.

Looking forward for your reply.

[FatePhenom]

Ok,

I have found a solution which works. It is stupid at this point, but it works. Only requirement to have Windows 7/10 or Server 16/19.

I will have an update tomorrow for the workaround. 

[FatePhenom]

So here's an update:

A temporary fix in order to, at least, have 4 GPUs linked together is by installing drivers from Q3 2019.

I am not able to manually pinpoint in device manager the 2023 Q1 drivers in order to install them but still keep using the 2019 GUI, because I am getting an error. I highly suspect that this is because they're "pro" version with all the safety features enabled? 

Who knows?

A little interesting fact. The 2019Q3 drivers give me only about 2-3% better performance in benchmarks compared to 23Q1 drivers that link 3 out of the 4 GPUs. I guess that is because of bad scaling after the 3rd GPU and because the 23Q1 possibly offer somewhat "increased performance" vs. the 2019 version face-to-face.

I really hope the Q2 2023 version of drivers take this into account. As I've always run 2 dual GPU cards and I am pretty sure this is the only time I'm facing this problem.