The DirectX 12 Performance Preview: AMD, NVIDIA, & Star Swarm
by Ryan Smith on February 6, 2015 2:00 PM EST- Posted in
- GPUs
- AMD
- Microsoft
- NVIDIA
- DirectX 12
Frame Time Consistency & Recordings
Last, but not least, we wanted to also look at frame time consistency across Star Swarm, our two vendors, and the various APIs available to them. Next to CPU efficiency gains, one of the other touted benefits of low-level APIs like DirectX 12 is the ability for developers to better control frame time pacing due to the fact that the API and driver are doing fewer things under the hood and behind an application’s back. Inefficient memory management operations, resource allocation, and shader compiling in particular can result in unexpected and undesirable momentary drops in performance. However, while low-level APIs can improve on this aspect, it doesn’t necessarily mean high-level APIs are bad at it. So it is an important distinction between bad/good and good/better.
On a technical note, these frame times are measured within (and logged by) Star Swarm itself. So these are not “FCAT” results that are measuring the end of the pipeline, nor is that possible right now due to the lack of an overlay option for DirectX 12.
Starting with the GTX 980, we can immediately see why we can’t always write-off high-level APIs. Benchmark non-determinism aside, both DirectX 11 and DirectX 12 produce consistent frame times; one is just much, much faster than the other. Both on paper and subjectively in practice, Star Swarm has little trouble maintaining consistent frame times on the GTX 980. Even if DirectX 11 is slow, it is at least consistent.
The story is much the same for the R9 290X. DirectX 11 and DirectX 12 both produce consistent results, with neither API experiencing frame time swings. Meanwhile Mantle falls into the same category as DirectX 12, producing similarly consistent performance and frame times.
Ultimately it’s clear from these results that if DirectX 12 is going to lead to any major differences in frame time consistency, Star Swarm is not the best showcase for it. With DirectX 11 already producing consistent results, DirectX 12 has little to improve on.
Finally, along with our frame time consistency graphs, we have also recorded videos of shorter run-throughs on both the GeForce GTX 980 and Radeon R9 290X. With YouTube now supporting 60fps, these videos are frame-accurate representations of what we see when we run the Star Swarm benchmark, showing first-hand the overall frame time consistency among all configurations, and of course the massive difference in performance.
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damianrobertjones - Saturday, February 7, 2015 - link
??? Eh? The computer, with DX12, is working harder AND offering better results.bitcrazed - Saturday, February 7, 2015 - link
Windows 7 will remain in broad use in businesses for a while yet, but given that Win10 will be a free upgrade for everyone else means that we should see far faster upgrades to Win10 than prior OS'.Put it this way - who here with a gaming rig or a machine they game on regularly is going to say - "No, I don't want a free upgrade to this new fangled Win10 + DX12 nonsense - I prefer to play my games at 10 fps and to gradually fade into obscurity"?
TheinsanegamerN - Sunday, February 8, 2015 - link
Gamers also seem to upgrade at a much faster rate. windows 8+8.1 make up 30% of steam windows users, while they only make up 12% of the general market. given that its FREE, windows 10 will probably become very popular very quickly.wolrah - Saturday, February 7, 2015 - link
Why would you say that? Windows 10 will be a free upgrade for anyone on a DX11 compatible system and so far has been a great OS to use. At the moment there's literally no reason not to upgrade.If Microsoft doesn't screw it up and the users aren't change-hating morons about it, Windows 7 and 8 should be fading memories in a year or two as far as the gaming community is concerned. Corporate users will still be themselves and be slower to upgrade, but corporate users' relevance to new gaming APIs is minimal.
aliquis - Monday, February 9, 2015 - link
Another stab at Valve and their SteamOS.OpenGL NG is quite a bit away and this will likely make Linux lag behind Windows in gaming again. For now.
Also with Xbox for Windows 10 I assume they may have some competition (which is likely why they wanted to migrate to Linux in the first place, because app-stores on any OS have become the standard.)
eanazag - Monday, February 9, 2015 - link
I'd like to see an integrated graphics version of this. Intel and AMD APU. If you're feeling fiesty, an AMD APU with a second card in Crossfire.Question I would have in an APU related article. With APUs, does it now make even more sense to go with higher bandwidth RAM? Some suggestions for the CPUs: AMD 7850K (duh), AMD A-6, AMD A-8, Haswell (Intel 7, 5, and 3 plus a crappy Pentium), AMD Kabini (top sku), and the Crystalwell Pro.
I think this has big mobile implications. I'd like to see a choice of a performance cap at 30-60 fps and the remainder of what's left on the table delivered in less heat and longer battery life.
SparkySamza - Tuesday, February 10, 2015 - link
what do you mean under windows 10; are you talking about windows 7 or even windows 8.1 ?tviceman - Friday, February 6, 2015 - link
Ryan I appreciate the depth and analysis of all your reviews. Anandtech is always my first stop for analysis of new video cards and tablets. That said, the continued tardiness of the GTX 960 review, as well as the lack of any 970 memory performance investigations is really disheartening. Especially the 960, since it's now 2 weeks today since the NDA was lifted.Keep up the analysis, and hire extra help if needed. ;)
Stuka87 - Friday, February 6, 2015 - link
Uhm, they had an article on the 970 memory issues:http://anandtech.com/show/8935/geforce-gtx-970-cor...
tviceman - Friday, February 6, 2015 - link
They did have an article, but they didn't do any extensive investigations into performance when going over 3.5gb but staying within 4gb.