Review Index:
Feedback

Frame Rating Dissected: Full Details on Capture-based Graphics Performance Testing

Crysis 3 – HD 7970 versus GTX 680

View Full Size

Crysis 3 is the currently the biggest GPU hog and both the GTX 680 and HD 7970 handle it equally well at 1920x1080.  Even using our FRAPS metrics though, GTX 680s in SLI are scaling better than the HD 7970s in CrossFire.

View Full Size

The frame time plot from our Frame Rating system shows another instance though of CrossFire’s inability to keep consistent animation on the screen.  The single card configurations are pretty consistent with each other but both also exhibit some tiny bumps in frame times on a repeating pattern, obviously a particular of the CryEngine.  SLI does have some increases in frame time variance across the board with a few minor “hitches” as well.  CrossFire though appears to be alternating between 2ms frame times and up to 50ms frame times resulting in…

View Full Size

Not only a lower observed frame rate but a frame rate that is LOWER than the single card!  I can tell you from first-hand experience that this definitely was the case in play through as well; it felt slower than the single card experience.

View Full Size

SLI looks fantastic in this graph and is able to take the matching performance of the GTX 680 and HD 7970 up from 30 FPS average for the entire run to 57 FPS.

View Full Size

Our custom ISU rating tells me that the GTX 680 SLI configuration looks GREAT and only differs from the single card configurations at 95% and above percentile.  The HD 7970 in CrossFire though shows huge amounts of variance from the outset and in fact does exhibit a lot of stutter in game as well.

 

View Full Size

At the higher resolution the single card HD 7970 as a slight edge over the GTX 680 this time around and this time the scaling of CrossFire appears to be faster than SLI.

View Full Size

A quick glance at our results from the observed frame rate clearly shows that isn't the case though as only in short bursts does the CrossFire experience actually match that of the dual GTX 680s in SLI.

View Full Size

Our frame time plot indicates where the alternating frame times in Crysis 3 occur with CrossFire and how it relates to the performance of SLI.  Other than the single large hitch seen at the 12 second mark or so in SLI, the GTX 680s handle Crysis 3 much better.

View Full Size

The GTX 680s are able to scale from about 19 FPS on average to 36 FPS - a solid 89% scaling factor.  The HD 7970 GHz Edition cards are not so impressive, only going from 21 FPS to 25 FPS but that quickly falls down to just even performance with a single card.

View Full Size

Ouch, another very poor result here for HD 7970s in CrossFire with Crysis 3 at 2560x1440 with as much as 25 ms of frame variance (nearly two full refresh cycels). 

 

View Full Size

This is one of the few Eyefinity runs for the HD 7970 CrossFire configuration that was able to run until completion and generate the necessary graphs for us.  So we’ll finally get to see some interesting results.  Even at first glance, we can tell that something here isn't quite right.  According to FRAPS, the HD 7970 is pushing out more than 200 FPS to the screen on Crysis 3 at 5760x1080, which is obviously inaccurate. 

View Full Size

Ouch, there are definitely some problems here, not the least of which is the graphs poor setting of range maximums (will fix soon!)  Notice the spots on the plot of the orange line (HD 7970 CF) where there is no data – that indicates a dropped frame and a lot of frame time variance. 

View Full Size

Removing those and any runts we find that the observed FPS is actually right in line with that of the single HD 7970 graphics card.  Also, without the CrossFire misreported results out of the window, the update scale helps us see the scaling that the GTX 680s in SLI. 

View Full Size

Here again is another one of our RUN files to show you the affects of dropped frames on Eyefinity testing.  FRAPS based frame rates sky rocket up though the observed frame rate is much lower, in line with a single HD 7970 GHz Edition card.  There are some runts involved in this but the biggest factor is obviously the dropped frames (missing colors in our pattern).

View Full Size

Again, for comparison, here is the RUN graph for the GTX 680s running in SLI at 5760x1080.  Notice that the frame rate is consistent with no drops or runts.

View Full Size

Interesting results here with the CrossFire setup taking a lower position across the board in our percentile minimum frame rate graphs. Also, we see the pair of GTX 680s in SLI start out much faster than anything else tested but at the 94th percentile or so fall below that of the HD 7970.

View Full Size

Keeping mind that we are looking at pretty low frame rates across the board, the HD 7970 has the best overall result here in our ISU graph with the least amount of frame variance over the course of our 60 second run.  Obviously CrossFire has a big issue once again and see significant variance starting at the 50th percentile and it only gets worse from there.

March 27, 2013 | 04:34 PM - Posted by Ryan Shrout

I'll see if we can take a look at that.

March 29, 2013 | 12:31 PM - Posted by jgstew

The whole time I was reading this article, I was more and more curious how Virtu's technology would effect things. I'm curious about more than just their Virtual V-sync, but their other options as well for both single and multiple GPUs. Virtu has not had the scaling that SLI & Crossfire have had, but perhaps their technology would show well in other areas with this analysis.

I do feel that Frame Rating & the input to display latency are much more interesting metrics.

Great work on the article.

March 27, 2013 | 02:32 PM - Posted by serpinati of the wussu (not verified)

I've read somewhere that this will not be the norm for pcper to do this type of testing with all video card reviews (too labor intensive). Is this true?

If it is true, will pcper at least record the frame data and simply give it a quick look to make sure video cards aren't doing something absolutely crazy (for example, if you were reviewing those 7970's crossfire you might not plan to actually to analyze the frame times, but you would at least look over the recorded frames anyways and catch the crazy runt frames and mention it in your reviews.)

March 27, 2013 | 04:34 PM - Posted by Ryan Shrout

No, my plan is to take this route going forward.

March 27, 2013 | 02:57 PM - Posted by Anonymous (not verified)

Greatly appreciate the work behind this! And opening up the tools / scripts to everyone, pushing it to other hardware magazines. Huge kudos! Oh, and you should slap Anandtech over the head for not even mentioning your involvment into the new metering method in their introductory article, that only mentions nVidia...

Is there any way to determine latency between t_present and t_display? If not, it should be - maybe some kind of timestamp could be worked into the overlay? Because that would be interesting not only in the context of VSync, but also regarding nVidias frame metering, which must take some time analyzing the frametimes. Supposedly, AMD has some smoothing algorithm coming up for Crossfire as well, so there it would also be valuable information.

Regarding Adaptive / Smooth VSync: They clearly come off too good in this article. They're not the focus of the article of course, still a little more thought should have been put behind this, considering the amount of time taken to create this awe inspiring effort of an article and the tools behind it. Adaptive VSync turns VSync off when tearing is most annoyingly visible, i.e. at framerates below monitor refresh rate - true triple buffering (instead of the queue nowadays called triple buffering) would be the good solution here. Smooth Vsync does not seem to do anything particularly positive judging from what little measurement is available in the article - only time (further tests that is) will tell what it actually does...

March 27, 2013 | 04:36 PM - Posted by Ryan Shrout

We have more research into the different NVIDIA Vsync options coming up, stay tuned.

As for the timestamp different to check for the gaps between t_present and t_display...we are on that same page as well.  :)

March 27, 2013 | 02:57 PM - Posted by Mawrtin (not verified)

Have you tried CF using radeonpro? Apparently it offers some kinda of Dynamic V-sync similar to nVidias adaptive if I'm not mistaken.

March 27, 2013 | 05:03 PM - Posted by Marty (not verified)

No, it does not. It's a frame limiter, which eliminates some of the stutter, but causes more lag (increases latency).

March 27, 2013 | 03:16 PM - Posted by Mangix

Hmmm. I wonder if there is a difference between Double and Triple Buffered VSync. Newer Valve games support both. Would appreciate testing there.

Also, are there driver settings that help/harm frame rating? Nvidia's Maximum Pre-rendered frames setting sounds like something that can have an effect.

March 27, 2013 | 04:25 PM - Posted by xbeaTX (not verified)

AMD has complained on Anandtech for this type of test using fraps ... now anyone know the real situation and it's shocking
this article sets the new stantard of excellence ... congratulations and thanks for the enormous work done... keep it up! :)

March 27, 2013 | 04:37 PM - Posted by Ryan Shrout

Thank you!  Help spread the word!

March 27, 2013 | 10:55 PM - Posted by TinkerToyTech

Posted to my facebook page

March 27, 2013 | 04:40 PM - Posted by Marty (not verified)

Ryan, I've a suspicion that you wanted to select Adaptive VSync on NVidia, but have selected Adaptive (half refresh rate) instead in the control panel. Would you please check it out.

March 28, 2013 | 02:20 AM - Posted by showb1z (not verified)

²

Other than that great article. Would also be interested in results with frame limiters.

March 27, 2013 | 05:23 PM - Posted by Dan (not verified)

This site is so awesome that it is one of th eonly ones that I disable Adblock in Chrome for. You deserve the ad $'s.

Rock on, Ryan and crew!

March 29, 2013 | 07:37 AM - Posted by Ryan Shrout

Thank you we appreciate it!

March 27, 2013 | 05:45 PM - Posted by Mike G (not verified)

Thanks for the all of the time taken to accurately test and then explain your frame rating methods to us. I wonder if AMD would be willing to have a representative come on and speak on how they will be addressing this issue. I for one will be holding off purchasing an additional 7970 at this time.

March 27, 2013 | 06:43 PM - Posted by bystander (not verified)

They have, with AnandTech, though the person they spoke to was the single GPU driver guy, they did mention they have a plan to offer fixes in July.
http://www.anandtech.com/tag/gpus

March 27, 2013 | 06:51 PM - Posted by Soulwager (not verified)

Is your capture hardware capable of capturing 1080p @ 120hz? The data rate should be less than 1440p@60hz.

Also, I would like to see some starcraft 2 results. It's frequently CPU limited, and I'm wondering how that impacts the final experience when compared to a gpu limited situation. I'd recommend the "unit preloader" map as a benchmark run, once to pre-load all the assets and again for the capture.

March 29, 2013 | 07:38 AM - Posted by Ryan Shrout

Actually, I think 1080p@120 is a higher pixel clock than 25x14@60; we tried to do basic 120 Hz testing right before publication without luck but we'll be trying again soon.

As for SC2, we'll take a look.

March 29, 2013 | 12:00 PM - Posted by Soulwager (not verified)

You're right, the pixel clock is higher. I guess I was only thinking about total number of pixels that need to be recorded, but the smaller resolution is more heavily impacted by overscan.

March 27, 2013 | 09:28 PM - Posted by SPBHM

great stuff.

I would be interested in seeing some results with some framerate limit, not from vsync, but another limit, something like FPS max 45 for Crysis 3 (higher than a single card, around the average for the CF), you can easily do that with dxtory

March 27, 2013 | 09:49 PM - Posted by Trey Long (not verified)

Its nice to see the truth come out. Save the excuses and fix it AMD.

March 28, 2013 | 03:41 AM - Posted by Carol Smith (not verified)

Why did you completely ignore AMD's RadeonPro freeware ?
Which offers and has offered Dynamic V-Sync that's superior to Nvidia's Adaptive V-Sync for years now.
Tom's Hardware seems to be the only site that actually used this utility to make a fair comparison between SLI and Crossfire.

RadeonPro's Dynamic V-Sync was shown to be clearly superior to Nvidia's Adapative V-Sync Implementation .

Here is the Tom's link
http://www.tomshardware.com/reviews/radeon-hd-7990-devil13-7970-x2,3329-...

I hope that you learn from your fellow journalist's to include this fantastic solution in your upcoming article.
Thanks for your hard work and good luck.

March 28, 2013 | 06:27 AM - Posted by Marty (not verified)

A frame limiter improves stuttering, but increases lag. You loose some Fps too. So you have to decide between the devil and lucifer in the case of Crossfire.

March 29, 2013 | 07:01 AM - Posted by Carol Smith (not verified)

Exact same thing with Nvidia SLI and Adaptive V-Sync, if you don't want stuttering you have to sacrifice framrates.

March 29, 2013 | 07:39 AM - Posted by Ryan Shrout

I'm going to take a look, but this is NOT "AMD's" software.

March 28, 2013 | 03:50 AM - Posted by Andre3000 (not verified)

Thanks for the eye opener! Which AMD drivers have been used for this review? I have read the article.. but i might have missed it?

March 29, 2013 | 07:39 AM - Posted by Ryan Shrout

For AMD we used 13.2 beta 7 and for NVIDIA we used 314.07.

March 29, 2013 | 08:27 AM - Posted by Steve (not verified)

Ryan: Is it possible to test AMD's CF with older drivers to see if this problem has been around for a long time or if it is a more recent problem with AMD's continuous driver upgrades to improve speeds?

Post new comment

The content of this field is kept private and will not be shown publicly.
  • Lines and paragraphs break automatically.
  • Allowed HTML tags: <a> <em> <strong> <cite> <code> <ul> <ol> <li> <dl> <dt> <dd> <blockquote><p><br>
  • Web page addresses and e-mail addresses turn into links automatically.

More information about formatting options

By submitting this form, you accept the Mollom privacy policy.