GeForce + Radeon: Previewing DirectX 12 Multi-Adapter with Ashes of the Singularity
by Ryan Smith on October 26, 2015 10:00 AM ESTAshes GPU Performance: Single & Mixed 2012 GPUs
While Ashes’ mutli-GPU support sees solid performance gains with current-generation high-end GPUs, we wanted to see if those gains would extend to older DirectX 12 GPUs. To that end we’ve put the GeForce GTX 680 and the Radeon HD 7970 through a similar test, running the Ashes’ benchmark at 2560x1440 with Medium image quality and no MSAA.
First off, unlike our high-end GPUs there’s a distinct performance difference between our AMD and NVIDIA cards. The Radeon HD 7970 performs 22% better here, just averaging 30fps to the GTX 680’s 24.5fps. So right off the bat we’re entering an AFR setup with a moderately unbalanced set of cards.
Once we do turn on AFR, two very different things happen. The GTX 680 + HD 7970 setup is an outright performance regression, with performance 40% from the single GTX 680 Ti. On the other hand the HD 7970 + GTX 680 setup sees an unexpectedly good performance gain from AFR, picking up a further 55% to 46.4fps.
As this test is a smaller number of combinations it’s not clear where the bottlenecks are, but it’s none the less very interesting how we get such widely different results depending on which card is in the lead. In the GTX 680 + HD 7970 setup, either the GTX 680 is a bad leader or the HD 7970 is a bad follower, and this leads to this setup spinning its proverbial wheels. Otherwise letting the HD 7970 lead and GTX 680 follow sees a bigger performance gain than we would have expected for a moderately unbalanced setup with a pair of cards that were never known for their efficient PCIe data transfers. So long as you let the HD 7970 lead, at least in this case you could absolutely get away with a mixed GPU pairing of older GPUs.
Facebook
Twitter
RSS
180 Comments
View All Comments
JamesDax3 - Monday, October 26, 2015 - link
Agreed. Let's see the test.[-Stash-] - Monday, October 26, 2015 - link
Very interesting first data.Also, where's the 980Ti SLI, Titan X SLI, Fury X Crossfire, Fury Crossfire comparison data? I'd like to see how this compares to the currently existing technology.
extide - Monday, October 26, 2015 - link
I don't think current SLI/CF actually works with DX12 -- although I could be wrong.Ryan Smith - Monday, October 26, 2015 - link
Not without a bit more work. That would be the implicit multi-adapter option.Manch - Monday, October 26, 2015 - link
Does the I7 Surface book have the 540igpu like the surface pro? If so how does it compare to the dGPU in the book. If they're similar in performance would AFR work on that? I heard it was supposed to be pretty goodDanNeely - Monday, October 26, 2015 - link
No. The surface book uses an I7-6600U with HD 520 graphics that has a minimum CPU 2.6GHz CPU clock and can turbo to 3.4. The Surface 4 Pro uses an i7-6650U that has Iris 540 graphics but only guarantees 2.2GHz, although it can still turbo to 3.4GHz.Manch - Monday, October 26, 2015 - link
Oh that's too bad. I would like to see an attempt to AFR those igpu and dgpu. Even a modest bump would be better than nothing. Either way I just want to see what it doesManch - Tuesday, October 27, 2015 - link
Why the distinction with regards to the ability to turbo between the two. Does the Surface pro dissipate heat poorly compare to the book? For both the guts are all crammed into the same locationsDanNeely - Tuesday, October 27, 2015 - link
They can both turbo to 3.4GHz. However the CPU in the surface has 2x as many GPU cores; when it's going at full power there's less headroom for the CPU which is why Intel set the minimum guaranteed speed 400 MHz lower.medi03 - Monday, October 26, 2015 - link
It's mentioned in the article:"As a result NVIDIA only allows identical cards to be paired up in SLI, and AMD only allows a slightly wider variance (typically cards using the same GPU)."
Although sounds misleading to me.