Slashdot Mirror
New GPU Testing Methodology Puts Multi-GPU Solutions In Question
Vigile writes "A big shift in the way graphics cards and gaming performance are tested has been occurring over the last few months, with many review sites now using frame times rather than just average frame rates to compare products. Another unique testing methodology called Frame Rating has been started by PC Perspective that uses video capture equipment capable of recording uncompressed high resolution output direct from the graphics card, a colored bar overlay system and post-processing on that recorded video to evaluate performance as it is seen by the end user. The benefit is that there is literally no software interference between the data points and what the user sees, making it is as close to an 'experience metric' as any developed. Interestingly, multi-GPU solutions like SLI and CrossFire have very different results when viewed in this light, with AMD's offering clearly presenting a poorer, and more stuttery, animation."
That unpossible. :-P
Lost at C:>. Found at C.
My AMD is cranking out Bitcoin hashes 15 times faster than an equivalently priced Nvidia so I'm okay with the results of this article.
I'm sure that AMD, the losing party, will dispute the results and come up with its own methoology to counter this.
Then again, everyone knew nVidia high end cards are better, so was this new test really necessary??
As an owner of a Crossfire setup, it's obviously not a 2x improvement over a single card; however, it's also a marked improvement over a single card. When I first set up this rig (August), I had problems with micro-stutter.* Now, though, after AMD's newer drivers and manually limiting games to 59 FPS, I don't see it anymore; games appear smooth as silk.
At a mathematical level, it may not be a perfect solution, but at a perceptual level, I am perfectly satisfied with my purchase. With that said, buying two mid-line cards instead of one high-end card isn't a good choice. Only buy two (or more) cards if you're going high-end.
*I was initially very disappointed with the Radeons. That's no longer the case, but I will probably still go nVidia the next time I upgrade, which hopefully won't be for years.
If you can't convince them, convict them.
It started when people began to look not only at average frame rate, but at *minimum* frame rate during a benchmark run. That shows how low the FPS can dip, which was the beginning of acknowledging that something in the user-experience mattered beyond average frame rate. It has gotten a lot more advanced, as pointed out in the article here, and this sort of information is very helpful for people building or buying gaming computers. I use info like this on an almost daily basis to help my customers get the best system for their needs, and I greatly appreciate the enthusiasts and websites which continue to push the ways we do testing!
William George
99th percentile frame times. That gives you a realistic minimum framerate, discarding most outliers (many games, particularly those using UE3, tend to have a few very choppy frames right on level load, that don't really affect performance).
Agree 100%. Ill help someone build a multi-GPU system, but i wont run one at home unless its an experimental rig.
Good-bye
This is interesting from a developer standpoint as well. This means we are wasting processing time rendering frames and are only displayed for a handful of milliseconds. These frames could be dropped entirely and that processing time could go to use elsewhere.
The new methodology shows that nVidia SLI gets excellent results. However, I've owned SLI solutions, both two 285s and a 290. Neither one was satisfactory. The higher failure rate was of particular note. One of the 285s failed, I RMAd it, got a 290, eventually that failed... On top of that, even when things were working, there were lots of problems. Some games didn't run correctly. Crysis, for example, didn't seem to like SLI; it would get into a bizarre state where the screen would begin flickering rapidly between black and normal frames, and you'd have to restart the game to recover. The problem never occurred in the same machine when I disabled SLI.
After that experience, both with dual-card SLI and single-card SLI, I decided it just wasn't worth it, and that my money was better spent on a good single-GPU solution. I currently have a single GTX 670, which works fine.
As a long-time GTX 295 owner, I've known for quite a while that my eyes are really good at seeing stuttering. For a few years, my GTX 295 did a splendid job keeping up with games, and as long as I could manage 60 FPS everything went seemed pretty smooth. I did have a few moments where I did see micro-stuttering but I found that either enabling V-sync or enabling frame limiting solved the problem. As you can see in this diagram http://www.pcper.com/files/review/2013-02-22/fr-3.png it's very possible that your GPUs synch up perfectly, producing two frames at the same time effectively causing every other frame to never reach the screen. Forcing games to synchronize to a certain FPS either via V-sync or frame limiting therefore helps the GPUs render at perfect intervals, assuming your hardware can render at that speed (usually 60 FPS).
And there's my point. SLI and Crossfire works perfectly fine as long as your hardware can pump out 60 FPS so you can synch it to that frame rate. As soon as it drops below that for even just a few seconds, it's easy as hell to spot a drop to 55 FPS that looks like 30-40. Therefore, SLI and Crossfire has tremendous value at their time, but are far from future-proof since as soon as you go under 60 FPS you basically drop to singe GPU framerates. For me, that wall was hit around when I started playing BFBC2, and I'm forced to play BF3 at low to ensure a minimum 60 FPS at all times.
A multi-GPU solution is a great investment for enthusiasts who change upgrade their hardware every year or two, but a horrible mistake for people expecting it to last several years.
> Besides, 60 fps, which is the refresh of the "image" is more then the human eye can distinguish
No it is not. A few us gamers can tell the difference between 60 Hz and 120 Hz.
The "practical" limit is anywhere from 72 Hz - 96 Hz. Sadly I'm not aware of anyone who has actually a done study what the practical limit is.
If I'm buying a GPU for a video game, I only care about how it benchmarks on video games.
Uh... No, you don't. You care how it actually PLAYS the games. Benchmarks are just an indication used for purchasing the GPU, and this article talks about a better way of measuring gaming performance to make better decisions.
> ability to detect with consistent frame rates, and ability to detect a stutter
This a thousand times!
Lag is OK as long as it is consistent.
The nice thing about targeting a _minimum_ of 120+ Hz is that you can get proper 3D 60 Hz "for free." :-)
I discovered this about a year ago, when i wanted to add a 3rd monitor to my system, and discovered I couldn't do it in Crossfire mode with my dual 4850s, but COULD do it if i turned it off. Productivity being slightly more important to me than game performance, I turned it off and hooked up my 3rd monitor.
A few days later I decided to fire up Skyrim, and didn't notice any discernible drop in performance at all. My settings were all on medium, just because the cards were a few years old, but still, I expected to see *some* performance hit going from 2 GPUs to 1.
I have since upgraded to a 7950 that supports 3 monitors, but I'm never doing that SLI/Crossfire shit again.