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FPS Benchmarks No More? New Methods Reveal Deeper GPU Issues
crookedvulture writes "Graphics hardware reviews have long used frames per second to measure performance. The thing is, an awful lot of frames are generated in a single second. Calculating the FPS can mask brief moments of perceptible stuttering that only a closer inspection of individual frame times can quantify. This article explores the subject in much greater detail. Along the way, it also effectively illustrates the 'micro-stuttering' attributed to multi-GPU solutions like SLI and CrossFire. AMD and Nvidia both concede that stuttering is a real problem for modern graphics hardware, and benchmarking methods may need to change to properly take it into account."
Our eyes detect 'deltas' better than 'speeds', so if the odd numbered frames have a delay shorter than others, our eye will detect it. But this only affect setups with multiple GPU's. And is easy to fix. Just calculate the delta of the latest frame, and force the same delta, maybe use a buffer. This is not a problem once has ben detected, It may need some minor changes on engines, but thats all. IMHO.
-Woof woof woof!
After all, your average geek tends to know that movies happen at 24 FPS
Movies happen at a motion-blurred 24 fps. Video games could use an accumulation buffer (or whatever they call it in newer versions of OpenGL and Direct3D) to simulate motion blur, but I don't know if any do.
and television at 30 FPS
Due to interlacing, TV is either 24 fps, when a show is filmed and telecined, or a hybrid between 30 and 60 fps, when a show is shot live or on video. Interlaced video can be thought of as having two frame rates in a single image: parts in motion run at 60 fps and half vertical resolution, while parts not in motion run at 30 fps and full resolution. It's up to the deinterlacer in the receiver's DSP to find which parts are which using various field-to-field correlation heuristics.
and any PC gamer who has done any tuning probably has a sense of how different frame rates "feel" in action.
Because of the lack of motion blur, 24 game fps doesn't feel like 24 movie fps. And because of interlacing, TV feels a lot more like 60 game fps than 30.
The Crysis test loop measures the slowest frame, starting with the second loop (to avoid measuring disk performance). That "minimum FPS" number is what I personally use to benchmark graphics cards - it has always been the speed through the slow-to-render part of the map that matters.
Socialism: a lie told by totalitarians and believed by fools.
On the last page, in the last paragraph, he indicates that all of the data you just read through is shit and probably invalid. Turns out he was measuring the wrong place in the pipeline - before rendering - and what he measured doesn't track with the actual user experience.
I'd like my 5 minutes back, please.
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Someone has never written a term paper :)
Are you sure about this, or are you basing it on experience with really poor TV frame interpolation? That's not 120Hz. That's more like 30Hz with lots of fake frames.
Well played Sir. I used my overclocked Radeon HD 3650 to post this (almost as quick) reply...
by Anonymous Coward on Friday September 09, @10:10AM
by webmistressrachel (903577) Alter Relationship on Friday September 09, @10:39AM
19 minutes? Sounds about right.
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At least the GTA games exhibit the same behavior on computers that are ridiculously overpowered for those games (2x+ recommended processing power), and I'd bet the same will prove true of NFS:Uc - that slowdown happened on an i7 940. So it's not something you can take care of by throwing more processing power at the problem.
The L4D games all run silky smooth on my i7 940 system, so I don't think it's the same kind of problem.
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