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

Capture Hardware and Extracting the Data

Capture Hardware

Once we have the overlay working, the next step in our Frame Rating process is to actually capture the video for later analysis.  While that sounds easy, it is far from the case.  Capturing the video on the testing system is out of the question. Instead we are using an external capture system built around an Ivy Bridge platform and a high-end capture card from Datapath, the VisionDVI-DL.

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This card is capable of capturing video at 2560x1600 at 60 Hz with throughput as high as 650 MB/s.  We were actually the first customer for this card in the US and have spent quite a few days on the phone with driver engineers to make sure this kind of testing process was successful.  Meant mainly for single frame captures, getting the VisionDVI-DL to really meet the specifications turned out to be a more complicated process than we’d hoped.  The good news is we have it all figured out now and can reliably capture the necessary video.

The VisionDVI-DL essentially acts like and shows up as a monitor to the system.  It reports an EDID (extended display identification data) to the graphics card that is set through the driver on the capture system.  I am able to emulate a 1920x1080 monitor at 60 Hz refresh and up to a 2560x1440 @ 60 Hz as well.  Using a Gefen dual-link DVI splitter we can connect a single display output to the NVIDIA or AMD GPU (to avoid the issues of power consumption and GPU utilization with multiple monitors attached) and split the signal to our capture card and to a monitor for us to actually play the games.

With a data rate of nearly 500 MB/s when capturing video at 2560x1440 @ 60 Hz, some serious storage speed was needed for this capture system.  I decided to use our Pegasus R4 Thunderbolt array coupled with a set of four Corsair Force GS 240GB SSDs running in an RAID 0 array, giving us about 900 MB/s of write capability.

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I cannot overestimate the importance of a completely correct capture in this step of the Frame Rating process.  If you deviate from the 60 Hz record rate even a single frame the data becomes basically useless.  Dropping a frame on the capture side would show up as dropped frames from the graphics card so avoiding that is paramount.  The software used for this capture will likely be VirtualDub on other sites that you see, and that was the program we used originally too.  However, the inability to automate the settings and having to re-adjust the options each time you load the program became a hassle so we developed our own that uses DirectShow filters and the Windows Platform SDK. 

 

Extracting the Data

Once you have the recorded raw AVI file, (that is about 25GB – yes GB – from a 60 second capture at 2560x1440) the next step is to actually read the colored bars and generate frame time data, runt data and drop data.  Using a basic DSP application, the extractor reads in each frame of the video sequentially and determines the number of scanlines in height that each color on the overlay bar has and records that information in an XLS file.

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This is probably the most fool-proof part of the process.  I have uploaded a few example XLS files right here for you to see the output.

March 28, 2013 | 07:20 AM - Posted by Beany (not verified)

I agree. I have 2x 6970 and the Crossfire results here are just embarrassing for AMD. It clearly don't work well and i've noticed myself with certain games, because you don't need graphs and stuff, as often you can see it with your own eyes. It's just BAD.

I used to build hundreds of PC's with both Nvidia and AMD, and from that experience i also noticed that 1) NV's drivers are generally better and less problematic and 2) Crossfire don't work as well as SLI.

The only reason i use AMD is for image quality. Not 3D/gaming stuff but general image output on the desktop. Colours and whites look better and more intense with AMD cards on my high-end monitors (but without being saturated), and no amount of tweaking on NV hardware will get this stuff to look as good. I've tried it with multiply different monitors and AMD just looks better. NV hardware is washed out in comparison. Most people wont be able to tell the difference and you need a good IPS diplay to properly notice but it's always bothered me because i'm a graphics designer and image quality freak. If NV sort this out i'll switch to them instantly.

March 28, 2013 | 07:20 AM - Posted by Beany (not verified)

I agree. I have 2x 6970 and the Crossfire results here are just embarrassing for AMD. It clearly don't work well and i've noticed myself with certain games, because you don't need graphs and stuff, as often you can see it with your own eyes. It's just BAD.

I used to build hundreds of PC's with both Nvidia and AMD, and from that experience i also noticed that 1) NV's drivers are generally better and less problematic and 2) Crossfire don't work as well as SLI.

The only reason i use AMD is for image quality. Not 3D/gaming stuff but general image output on the desktop. Colours and whites look better and more intense with AMD cards on my high-end monitors (but without being saturated), and no amount of tweaking on NV hardware will get this stuff to look as good. I've tried it with multiply different monitors and AMD just looks better. NV hardware is washed out in comparison. Most people wont be able to tell the difference and you need a good IPS diplay to properly notice but it's always bothered me because i'm a graphics designer and image quality freak. If NV sort this out i'll switch to them instantly.

March 28, 2013 | 05:24 PM - Posted by Anonymous (not verified)

Dont know if you read the patch notes for Radeon, But they stated that they have improved crysis 3 and more performance with their latest releases AND that they are working on GREATLY increasing CROSSFIRE performance. Keep an eye open PCPER!

March 28, 2013 | 08:35 PM - Posted by Anonymous (not verified)

lol - it's just amazing isn't it. We'll have the same excuse the politicians always give us...

" "Tired of dropping frames instead of opponents? Find a CrossFire™-certified graphics configuration that’s right for you."

" We had no idea!!!! "

I want to know how many YEARS this has been going on.

These tools need to be used on 3870 Cf on up - 4850 4870 5850 5860 6850 6870 6950 6970 and so on....

So for many years we have been fed a complete freaking lie across the board, and from every "scientific unbiased tester website"....
Just wow. If there are conspiracy theorists here, you missed this one, because right now full blown conspiracy (if amd seemed it knew what it was and is doing) would be the conclusion. (instead amd marketing lies and incompetence and pure luck at the massive cover up over many years looks correct)

I also have to say, PALMFACE !

This also SHAMES EVERY REVIEW SITE OUT THERE. lol How stupid they have been - they should have spent far less time attacking nVidia looking and hunting for every tiny chink in their armor they could dream up and squared off at AMD since these COMPLAINTS about Crossfire have been present since DAY ONE.

Just think, all those reviewers, all those tests, all those years, and complete obliviousness till now... and a CONSTANT HAMMERING on people like me who tried in vain to point out the CF issues.
"it's your imagination"
"you're crazy"
"nVidia shill"
"paid operative"
"I don't see anything wrong ! "

Just W O W.

March 29, 2013 | 05:59 AM - Posted by John Doe (not verified)

You're a moron and have some real issues.

I ran that HD 2900 CF setup up to 200 HZ and haven't had a SINGLE frametime issue with it.

I was playing Cube on it at 160 HZ on a Diamondtron SB2070 and it didn't skip a SINGLE beat.

March 29, 2013 | 12:01 PM - Posted by Anonymous (not verified)

LOL - a single example, untested, swears the amd fanboy, on an obsolete hd2900 said to be the most terrible hd flagship even by amd fanboys, and one game, from the historical mind of the fanboy....

R O F L - and you call me names.

No, we need the entire lineup of amd tested for the YEARS their scam has existed.

I feel a MASSIVE VINDICATION coming.

BTW - hold onto your undies feller, AS THIS SOFTWARE FCAT WITH THE COLOR BANDS IS BEING RELEASED TO THE PUBLIC FIRST ON MSI AFTERBURNER ON MONDAY AND THEN ON EVGA PRESICION X LATER IN THE WEEK !

ROFL - The truth is coming amd fan. NOTHING will stop it now.

March 29, 2013 | 03:31 PM - Posted by John Doe (not verified)

Indeed.

I bought those 2900's because they were fucking cheap as hell because I bought them SECOND HAND and had a couple of PULSE Digital PWM's and 512-bit bus with a ton of memory bandwidth and HDCP onboard.

How many words in that text did you had to Google?

April 2, 2013 | 09:15 PM - Posted by Anonymous (not verified)

Hey I, that's ME, I loved the HD2900, but all the amd fanboys were crying, it lost miserably to the nVidia flagship.
Have a good friend who got a Sapphire hd2900 "pro" version, but it wasn't the pro, as I recall it had an unlisted weird and in between 320 shaders with the 256 bus.
He had EXTENSIVE trouble with it - I spent countless hours hammering out the bugs in every board he ever ran it in - a Dell dimension 4700 for instance kept it locked at 500mhz core and 600mhz memory.
He hammered the crap out of it for years, he broke it three times, I resurrected it three times, then finally against advice he kept the pink rubbery foam strip off the VRMs upon reassembly after cleaning - he was told NOT to but insisted it was just a cushion and not needed - that freaking cooked it for good -
I didn't hate the HD2900 but every amd fanboy did, and said so, it was a crushing blow to their egos, as nVidia stomped it on performance.

March 29, 2013 | 03:50 PM - Posted by Anonymous (not verified)

yet another fan boy, this time on the nvidia side. (paid?)
i wish you all disappeared.

March 29, 2013 | 03:52 PM - Posted by John Doe (not verified)

I've never been paid by anybody in my entire life to speak garbage about a product.

You have absolutely no idea who I am, which just goes to show how much of an ignorant idiot you are.

Have a nice and a long life.

April 3, 2013 | 11:17 PM - Posted by Anonymous (not verified)

He was replying to me, please be able to follow the threading insets.

Now you were calling whom an idiot ? Uhh, nevermind.

April 10, 2013 | 06:21 PM - Posted by John Doe (not verified)

The more you speak to yourself, the more of a retard you'll realise you are.

March 29, 2013 | 03:51 PM - Posted by Anonymous (not verified)

Well it could just as well be "lazy" game developers not bothering to optimize for AMD and just going with nVidia and then just accepting the faults that comes when using AMD and just hoping no one notices??

March 29, 2013 | 03:51 PM - Posted by Anonymous (not verified)

Well it could just as well be "lazy" game developers not bothering to optimize for AMD and just going with nVidia and then just accepting the faults that comes when using AMD and just hoping no one notices?

March 29, 2013 | 04:05 PM - Posted by John Doe (not verified)

Yes.

April 3, 2013 | 11:15 PM - Posted by Anonymous (not verified)

lol

It happens on many AMD Gaming Evolved games that have direct amd/developer input fella.

Nice try but you obviously are clueless and a total amd fan.

March 27, 2013 | 10:50 AM - Posted by JonasMX (not verified)

My only concern is that in my country are a bunch of people don't care about this kind of stuff. They think is too boring and the readers don't care.

We are years behind what you are trying to demostrate and bring to light, but definitly I'll follow you like an example.

Thanks for you hard work

March 27, 2013 | 11:12 AM - Posted by Anonymous (not verified)

Hi Ryan
I was wondering if you could also post the RUN graphs for the 680 sli. I didn't get a clear picture from the article if the 680 sli also dropped any frames, had any runt frames or totally avoided those behaviors.

March 27, 2013 | 11:25 AM - Posted by Ryan Shrout

I'll do that now!

March 28, 2013 | 08:42 PM - Posted by Anonymous (not verified)

No drops no runts for nVidia 680 SLI - NONE

LOL

That's why they were left out... like no news is good news.

I feel so good about myself, so many years, so many attacks on me by so many raging amd lovers.
I sooooo want to see them cover their heads in shame and admit how treasonous they were.
Yes treasonous liars. (lol whatever couldn't think of the word)
I suspect heck would freeze over first.

Oh look at that the river styx has ice skaters on it.

March 27, 2013 | 11:32 AM - Posted by Eriol (not verified)

Great job on the article! This is how GPUs should be benched in the future.

What I would also like to see is how the input latencies are affected by things like vsync or nvidia frame metering. Also, digging deeper into how frame rate limits can help alleviate the stutter issues would be welcome. I found that back when I was testing 6950cf that a 3rd party fps limiter was the best solution combating micro stutter.

In the end CF is just not worth it atm, regardless of vsync or fps limiters. AMD has a lot of work to do to get CF sorted out. I doubt a new driver 2-3 months down the line will be the end of it, but hopefully they're good to go when the next gen arrives.

March 27, 2013 | 07:22 PM - Posted by Ryan Shrout

Input latency testing is my next target!

March 27, 2013 | 11:47 AM - Posted by JLM (not verified)

Great work and great review/article!

I do wish you guys had included the effects of a framerate limiter in addition to vsync, though... I've actually had a better experience using a framerate limiter through Afterburner on 7970 CF than I do with vsync; it seems to almost always remove stutter completely while also preserving the scaling.

March 27, 2013 | 07:30 PM - Posted by Ryan Shrout

I'll definitely be giving that shot!

March 27, 2013 | 12:20 PM - Posted by Anonymous (not verified)

What about older Nvidia cards?
What about Crossfire 6970s?

We played a bit of Natural Selection 2 the other day..meh..silly bunny jumpy game..imbalanced..go Marine..
Anyway..

Crossfire enabled 72 FPS
Crossfire disabled 64 FPS
What a ripoff!

Then we tried it on 2 GTX 580s same room and systems and almost the same results..

Multi GPU setups are just a ripoff unless you get Exactly DOUBLE for performance.

March 27, 2013 | 01:35 PM - Posted by John Doe (not verified)

Scaling depends on A TON of factors. GPU's, drivers, applications so on and so forth.

You need to understand the basics of these things before you throw out such pointless and silly statements.

If you want to compare scalability, first compare a pair of single cards in FurMark. Then SLi/CF them and compare again.

March 29, 2013 | 03:07 AM - Posted by Anonymous (not verified)

CF is failing in half the games across the board, and has been for some time.
TPU for instance is an example where he mentions it if you don't believe me.
That's the other big laugh, shouldn't have been recommended for a long time now.

Maybe AMD will actually do something now, I doubt it though, I suspect apologetics, misdirection, and lies.

March 27, 2013 | 02:26 PM - Posted by Noah Taylor (not verified)

What is or isn't a ripoff is completely subjective and will never be an agreed upon issue. However, you can get a great experience moving to multi gpu setups that isn't necessarily double performance. Hi resolution gaming especially, at 2560x most single cards can't quite get you to >40fps avg with everything turned up in most modern games and what we will see in the next year. If i can get 15 more fps at that resolution it really DOES make all the difference.

However, if I buy 2 graphics cards because AMD says that framerate is how i should rate their cards, and their are frames being counted that detract from the quality of the experience, and essentially bloat their test scores up to 300% over what is actually being displayed, then not only have we been deceived, but AMD has really scammed you, since the extra card is actually detracting from the experience in many ways.

March 27, 2013 | 02:34 PM - Posted by John Doe (not verified)

Moral of the story, get this before it goes out of stock.

http://www.newegg.com/Product/Product.aspx?Item=N82E16814187196

It's a card of limited availibity and is one hell of a damn good, limited custom design.

I'm eagerly waiting for mine to be shipped.

Heh.

March 29, 2013 | 03:58 PM - Posted by Anonymous (not verified)

2GB is not enough for 1080p this days.

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