SLI and Getting More out of the Second Card

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1

Anyone know of a way to tweak cards in SLI to get more out of the second card? Has anyone used Nvidia Profile Inspector or anything like that for this?

If you are going to comment SLI is dead: No, it is not dead. And it is not dead for Wow. It is alive and well, and NVLink, the link for RTX cards, actually makes SLI better than ever.

2

It depends on the cards. If a single card will run the game at the resolution you have it set to the other card is not going to do a lot. I get 60 percent load one card and 40 roughly on the other. with very little if any increase in performance. It also depends on the CPU.

While it is not dead. Many new titles are opting for multi GPU support and not SLI or Crossfire.

3

Thanks for your reply. :smiley: You say you aren’t getting much of a performance increase? How are you judging that? You are probably getting cooler temperatures, though, with no throttling? There are a lot of variables to play with, such as your quality settings and FPS limiting, etc. I haven’t done any testing with only one card, but have my FPS limited to keep the temperatures down. I am using a 4k monitor though.

To put it succinctly, I’d really like to up the FPS and/or graphics settings with the same or even lower temperatures by somehow setting things up to tap the second card more. Is that not possible? To give you an idea of what I mean, my first card is hitting 55 degrees while the second card is only hitting 37 degrees. That seems totally wacky when an ideal setup would seem to be more FPS or better graphics settings with both cards only hitting, say, 50 degrees. Does that seem silly? It makes sense to me.

Also, regarding the CPU, there is no bottleneck there in my case.

4

Disabling the second card results in only a minor decrease In FPS @4K.

The Temps are actually really low. Generally anything below 80C is great as temp.

It is very likely that with increased settings the primary card load will increase significantly with a minor increase on the second card.

5

I agree with you completely. So you know no way of tapping the second card more then? Have you ever used Nvidia Profile Inspector?

Edit: Problem solved. DirectX 11 did it.

6

The temperatures of both cards are now maxing out at 54 degrees, and both cards are typically around the same temperatures most of the time. The utilization of both cards is similar but higher on the first (no surprises there). This is with DirectX 11 in the game settings, in case you’d wondered.

7

A single 2080 is OVERKILL for WoW as it is more of a CPU based game, it will use WAY MORE of your CPU than you GPU. DirectX11 is a downgrade to DX12 and using SLI in DX11 to get the “most out of you card” is not how it should be done. The reason you see an improvement is DX11 doesn’t use some of the advanced features that DX12 does. SLI 100% does not provide an increase to World of Warcraft. Other AAA titles, of course it does, but not a game coded to specifically draw from one gpu.

8

It’s more likely due to the way that DX11 allows for SLI (and CFX) to be handled by the drivers. As such it’s extremely difficult (though not impossible) to code a DX11 title such that a second, properly configured GPU won’t get used; though you may need to take some time to determine which mode (AFR, SFR, etc) grants the best overall performance and quality.

DX12, by its very nature, requires any and all multi-GPU activity - whether it’s single- or mixed-vendor - to be handled by the renderer itself. As such it has to be specifically programmed for, without the automation that DX11 offered. It’s currently underutilised to the point that Microsoft released a set of libraries to help facilitate MGPU usage under DX12, which is exactly counter to the original intent of DX12.

In other words, what you’re seeing is that Blizzard has not incorporated MGPU into their DX12 renderer. They don’t get a choice in DX11.