FCAT VR: GPU And CPU Performance in Virtual Reality

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By Chris Angelini
published

The Effect of Quality Settings on Performance

How much difference is there, really, when you switch between quality presets in a VR game? Thus far, we’ve limited our benchmark runs to Chronos and its Epic settings. If you own a mainstream graphics card, though, that’s probably not ideal. We dropped a GeForce GTX 1060 6GB into our test system, unhooked the hardware-based capture machine, and compared the title's four available detail levels.

Surprisingly (to us, at least), a GeForce GTX 1060 is playable using the Epic options. An unconstrained frame rate just under 62 FPS is enough to facilitate a perfect 45 FPS output with every other frame synthesized by ASW (that’s 7290 total frames, 3645 of which are real). Not a single frame is dropped this way.

By simply toggling down to High quality, we get 6455 out of 7203 real frames from Nvidia’s GP106 processor. There’s a particularly demanding passage in the middle of the run where ASW flips on to deliver 729 synthesized frames. Then, when the algorithm determines it’s safe to jump out of ASW mode, it does so.

See those red dips sprinkled intermittently through the run, though? We register 19 dropped frames, which correspond fairly well to spikes in the frame time chart. They happen outside of ASW mode when a frame takes too long to be displayed in the current refresh interval.

Dialing back to Recommended detail circumvents the need for ASW altogether, and our GeForce GTX 1060 renders 7189 real frames out of 7196 total. The seven missing frames are dropped, though you can see this issue is far less prevalent when the graphics card isn’t teetering between ASW on and off. If Oculus wanted to be a little more aggressive about when it jumped into ASW mode, some of those drops could probably be avoided. But then it’d face the complexity of getting back out of ASW, which isn’t inconsequential.

The Low detail run doesn’t look good at all on-screen, but the relaxed graphics quality is great for performance. An unconstrained frame rate of 181+ makes it easy to sustain 90 real frames per second. Dropped frames still happen, but they’re not noticeable.


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Chris Angelini
Chris Angelini
Chris Angelini is an Editor Emeritus at Tom's Hardware US. He edits hardware reviews and covers high-profile CPU and GPU launches.
11 Comments Comment from the forums
  • ingtar33
    no ryzen? just an 8320?
    Reply
  • AndrewJacksonZA
    A really nice article and a great introduction to FCAT VR. Thanks Chris!

    Obvious request that probably everyone will ask of you: please include Ryzen in your tests once you have a sane moment after the hectic launch period. :-)

    Now that that's out the way, I can get to my actual question: I would like to know if "Game A" is available on both the Rift and the Vive, would FCAT VR be able to tell you what, if anything, the performance difference is given the same computer hardware please?

    Please can you also include multi-GPU setups. They can definitely help, depending on the title, e.g.
    https://www.hardocp.com/article/2016/11/30/serious_sam_vr_mgpu_nvidia_gtx_pascal_follow_up/5
    https://www.hardocp.com/article/2016/10/24/serious_sam_vr_mgpu_amd_rx_480_follow_up/

    I found this statement to be very interesting: "it’s possible to illustrate that 11ms isn’t an absolute threshold for rendering new frames at 90 Hz."

    Thank you
    Andrew
    Reply
  • cangelini
    Hi guys,

    Ryzen wasn't in my lab yet when this was written, but I do have plans there ;)

    Andrew, yes, FCAT VR should allow us to test the same title on two different HMDs and compare their performance.

    Multi-GPU is a plan as well, particularly once games begin incorporating better support for it (right now, that's a bit of a problem).
    Reply
  • WhyAreYou
    Thanks, looks good!
    Reply
  • playingwithplato
    Do FCAT VR's measurement algorithms tend to favor NVDIA chipsets? Curious, wonder if AMD will release a similar testing tool to measure buffer store/retrieval and render speed <11ms? Would like to see that applied to en environment with their GPUs.
    Reply
  • ffrgtm
    Fantastic article! I would love to see results with a secondary GPU (non-SLi) dedicated to physics and compare that to the cpu swap tests in AZ Sunshine you've just shown us.
    Reply
  • ffrgtm
    19429997 said:
    Do FCAT VR's measurement algorithms tend to favor NVDIA chipsets? Curious, wonder if AMD will release a similar testing tool to measure buffer store/retrieval and render speed <11ms? Would like to see that applied to en environment with their GPUs.
    A quote from another article on FCAT:

    "While the FCAT VR tool is developed by Nvidia, the company insists it is headset and GPU agnostic, and meant only to capture data. The tool itself doesn’t contain a benchmark; according to the company, the tool logs information directly from the VR runtime."

    I'm inclined to believe Nvidia's claim of brand blindness right now... but if AMD ever manages to put forth some real competition then I don't think we could be blamed for becoming more skeptical. It's hard to forget just how far Nvidia and AMD have gone to skew results in the past.
    Reply
  • AndrewJacksonZA
    19429089 said:
    Andrew, yes, FCAT VR should allow us to test the same title on two different HMDs and compare their performance.

    Multi-GPU is a plan as well, particularly once games begin incorporating better support for it (right now, that's a bit of a problem).
    Thank you.


    One thing that I might've missed in the article: Has Nvidia open-sourced FCAT and FCAT VR so that everyone can see the code, check it for unbiasedness (is that even a word? :-) and help contribute to the program to make it even better?
    Reply
  • cangelini
    Yup, check it out: http://www.geforce.com/whats-new/guides/fcat-vr-download-and-how-to-guide

    There's a download link in there. I'd be curious to hear from any TH readers who want to mess with it as well!
    Reply
  • thinkspeak
    Any chance of doing this again but with stock and OC on the maxwell, pascal and AMD cards? The 980 ti really opens up and they generally overclock well, in some cases exceeding the 1070 which would be useful for those debating an upgrading for VR
    Reply