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.
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mosu - Thursday, October 29, 2015 - link
Did you ever owned or touched an Iris HD 6000? or at least know someone who did?wiak - Friday, October 30, 2015 - link
eDRAM...if AMD goes HBM2 like they did in the past with ddr3 sideport memory
just a taught
AMD Zen 4-8 Core with Radeon (2048+ shaders, 2 or 4GB HBM2 (either as slot on mb or ondie like fury)
i think i read somewhere there will be a single socket for APUs and CPUs,
so amd lineup can be a Zen CPU with 8-16 cores for perf system and a Zen APU with 4-8 cores, 2048+ shaders and hbm2 for mainstream/laptops computers
Michael Bay - Thursday, October 29, 2015 - link
If it actually could, we would be able to buy it. No such luck.Revdarian - Thursday, October 29, 2015 - link
Well, it has currently two offerings, one called Xbox One, and the other one that is more powerful is called the Playstation 4.Those are technically APU's, developed by AMD, and can be bought at the moment. Just saying, it is possible.
Midwayman - Monday, October 26, 2015 - link
Seems like it would be great to do post effects and free up the main gpu to work on rendering.Alexvrb - Monday, October 26, 2015 - link
Agreed, as far as dGPU and iGPU cooperation goes I think Epic is on to something there. Free 10% performance boost? Why not. Now for dGPU + dGPU modes, I am not killed on the idea of unlinked mode. Seems like developers would have their work cut out for them with all the different possible configurations. Linked mode makes the most sense to me for consistency and relative difficulty to implement. Plus anyone using multiple GPUs is already used to using a pair of the same GPUs.Regardless of whether they go linked or unlinked though... I'd really like them to do something other than AFR. Split-frame, tile-based, something, anything. Blech.
Refuge - Monday, October 26, 2015 - link
For high end AAA Titles likened mode would be optimum, I agree. Allows for their fast releases, and still gives a great performance boost. Their target demographic is already used to having to jump through hoops to get the results they want. Getting identical GPU's won't affect them.For games with extended lifetimes like MMO's such as WoW, Swtor, etc, etc. Unlikened mode is worth the investment, as it allows your game to hit a MUCH wider customer base with increased graphical performance. These are crowds that are easy to pole for data so they would easily know who they are directing their efforts towards, and the lifespan of the game make the extra man hours a worthy investment.
Gadgety - Tuesday, October 27, 2015 - link
@alexvrb And game testers have their work cut out for them as well, testing all sorts of hardware configurations.In addition game developers will likely see the need for new skill sets, and likely this will benefit larger outfits being able to cope with developing and tuning their games to various hard ware combinations.
DanNeely - Tuesday, October 27, 2015 - link
I suspect most small devs will continue to use their engine in the normal way, not taking any more advantage of most of the DX12 multi-GPU features any more than they did SLI/XFire in DX11 or prior. The only exception I see might be offloading post-processing to the IGP. That looks like a much simpler split to implement; and might be something they could get for free from the next version of their engine.nightbringer57 - Monday, October 26, 2015 - link
Wow. I didn't expect this to work this well.Just out of curiosity... Could you get a few more data points to show how a Titan X + Fury X/Fury X + Titan X would fare?