DiRT 3
DiRT 3 (DirectX 11)
A continuation of the Colin McRae series, but without his name, DiRT 3 is one of the top racing games in the world and offers stunning imagery along with support for features of DirectX 11.
Our settings for DiRT 3
DiRT 3 was a game that only showed a couple of instances of runted frames in our HD 7970 testing so I was curious to see how a step down in performance levels would affect our results. Already we see that the Radeon HD 7950 CrossFire results aren't quite matching up in our FRAPS and Frame Rating testing.
Our plot of frame times shows us where those drops in observed frame rate occur on the CrossFire setup – the three big orange blobs towards the middle of the test run. The blue line that is the GTX 660 Ti SLI is definitely more consistent than the HD 7950s in CrossFire but it has some larger swings of frame time early in the benchmark. Both single cards perform quite well, however.
First, on single card performance, the HD 7950 is just barely keeping ahead of the GTX 660 Ti. The SLI results though jump from about 90 FPS to 155 FPS average which is much better than we see with CrossFire thanks to the scaling issues found above.
Keeping an eye on the scale on the left for frame time variance, even the HD 7950s in CrossFire aren't too bad, but they are the worst of this group.
The frame time issues are so bad in DiRT 3 that CrossFire HD 7950s are actually showing up as observed frame rates UNDER that of a single card!
Our frame time plot shows the large swings of the Radeon CrossFire results once again, but notice that the SLI results are actually tighter at 2560×1440; the added GPU bottleneck of the higher resolution results in a better result for NVIDIA and a worse result for AMD.
Our minimum FPS graph shows the significant scaling of the GTX 660 Ti cards in SLI and the lack thereof for CrossFire.
Only the Radeon HD 7950s have a big problem with frame time variance, but the difference is dramatic.
Observed frame rates on the HD 7950s in CrossFire are much lower again with some runts and dropped frames but the SLI results are consistent in both FRAPS and Frame Rating capture testing.
While nice to look at from a design perspective, the orange line that represents dual HD 7950 cards shows the "0 ms" dropped frames. The GTX 660 Ti cards in SLI do have some spikes and hitches but it seems pretty reasonable in real-world game play. Both single cards do quite well with tighter series' of results.
With SLI scaling from 38 average FPS to about 65 FPS, the GTX 660 Ti cards prove to be more than capable of running DiRT 3 at 5760×1080. The minimum FPS of the GTX 660 Ti SLI configuration does drop down a bit at the 90th percentile or so but it it consistently stays ahead of any other of our four options.
Because we are seeing drops rather than runts, the variance of the frames that remain for the Radeon HD 7950s in CrossFire isn't that bad – but don't think you can just look at this graph and get the whole story. The GTX 660 Ti SLI setup definitely has more variance than the single cards though is able to increase the average frame rate 71%.
I can’t believe the amount of
I can’t believe the amount of trolling over this article. I consider myself loosely an AMD fanboy when it comes to video cards. I don’t really have an issue recomending nVidia cards to friends if that is where their pricing falls but I, personally run AMD. I don’t see anything malicious about these articles and I find them very interesting and detailed. It’s not going to stop me from buying a 7950 within the next month to replace my 5850 (Which let’s be honest is still pretty darn good for today’s games). I will just be happy that AMD knows about the issue and is working on a solution so I can get a nice fully functional Crossfire set-up later when they drop in price.
OK, AMD admits a issue then
OK, AMD admits a issue then stop showing the comparisons with crossfire. What is the point is reviewing the same issues time and time again like something is suddenly going to change as we hit a different price point. This isn’t a comparison at this point. If what you say is true then post this as a buyer beware when reviewing AMD cards about crossfire. What your doing here is the same as reviewing a nVidia card nad every article mentioning AMD crossfire is broken.
If you want a single GPU card no issue. If you want multi GPU go with nVidia at this point or move up to the next higher single GPU AMD. But remember with crossfire X when this fix is in place you can continue to boost your performance buy adding the next gen AMD. All nVidia offers is physx.
I agree with all of that and
I agree with all of that and would also like to suggest PCper explores the 3rd party apps like radeon pro that fix a lot of these issues. Much more useful than telling us Xfire is broken over and over again
I agree with all of that and
I agree with all of that and would also like to suggest PCper explores the 3rd party apps like radeon pro that fix a lot of these issues. Much more useful than telling us Xfire is broken over and over again
I wouldn’t mind seeing 3-way
I wouldn’t mind seeing 3-way CF/SLI, as an article a while back by THG found 3-way CF helped a while back.
I would like seeing RadeonPro, but realize that the fixes all include FPS limiting, which obviously isn’t ideal.
I would also like to see different ranges of runt frames. 20 pixels high is 2% of your screen. That is really small. You could fairly increase that number some.
The exposure of Crossfire
The exposure of Crossfire problems will force AMD to fix it. HOW IS THIS A BAD THING?
The way this is a bad
The way this is a bad thing:
1. I own a 7950 Crossfire setup which looks perfect to me (I use RadeonPro), and my initial reaction was that I should sell them and buy Nvidia, imagine how this could impact sales of people just considering AMD. I think the results, while quite accurate in and of themselves, should be better quantified in the real world (lets be honest can anyone at PCPer in a blind test really tell the difference between AMD and Nvidia)?
2. The graphs completely misrepresent what is happening on the screen. If you look at these graphs you imagine this stuttering mess on the screen, the truth is nothing close to that (as I said I can watch my rig in the real world).
3. It is completely beating a dead horse, we get it, the Crossfire has “major issues” when you enhance and slow down the frames to a crawl (which has zero bearing on how it looks in the real world), no reason to post the same results for each Crossfire compatible card, we already know what they are.
I am no AMD fanboy, I want all of the info I can get so next time I drop $1,000.00 on video cards I have all of the available info, I just think the info should be presented in a more realistic form, to me this is all quite inconsequential to real world gaming performance.
The problem isn’t that you
The problem isn’t that you don’t get playable frames in crossfire. It is that you aren’t gaining full benefit from crossfire. When choosing between Crossfire and SLI, what will help you more so you can plan ahead.
And if you use v-sync, the limited testing has shown it helps or fixes the issue (only tested on 2 games so far, it could be the FPS limiting aspect that helps, and not v-sync itself).
“The problem isn’t that you
“The problem isn’t that you don’t get playable frames in crossfire. It is that you aren’t gaining full benefit from crossfire.”
That right there to me is an accurate and thoughtful representation of what is going on here. That would have been a much more accurate way to present this information instead of the current “AMD Crossfire is a stuttering mess” message.
I have been on every review
I have been on every review website there is and was for well over a decade, and argued with every fanboy of every type – and NEVER has a single amd fan or otherwise EVER MENTIONED “radeon pro”…
So who cares if NOW, you use it. For YEARS not a single amd fanboy CF user was using it, and if they were THEY LIED AND KEPT IT A SECRET BECAUSE THEY KNEW AMD SUCKS WITHOUT IT.
So who really cares at this point what lying hidden crutch amd needs for a “quicky bandaid patch” for it’s crapster crap crossfire epic failure ?
It’s a big fat excuse for YEARS of total loserville and lies.
I’ll also mention once v-sync and radeon pro hack the frame rate down to 30 or 60, YOU MIGHT AS WELL NOT USE AN AMD CROSSFIRE SOLUTION AT ALL BECAUSE YOU CANNOT USE FRAME RATE POTENTIAL ON IT FULLY, YOU HAVE TO CRIPPLE IT FOR IT TO WORK.
What we need now is a 30fps chart and 60 fps chart with crap amd cards listed running vsync and radeon pro and the chart can tell us which pieces of crap can do 30 and 60 fps and we can THROW OUT EVERY OTHER FRAME RATE EVER LISTED FOR THE CRAP AMD CARDS.
“The problem isn’t that you
“The problem isn’t that you don’t get playable frames in crossfire. It is that you aren’t gaining full benefit from crossfire.”
That right there to me is an accurate and thoughtful representation of what is going on here. That would have been a much more accurate way to present this information instead of the current “AMD Crossfire is a stuttering mess” message.
Interesting test, if what you
Interesting test, if what you have tested is valid, AMD is in deep-sh*t once again. If not, there is some kind of money transaction going on…
Nonetheless, thanks for all your efforts.
Quick Google “geforce frame
Quick Google “geforce frame metering” and you will find out why the nVi cards rarely have runt frames. In fact, nVi cards DO have them. They just delays those frames a bit to match with other good frames’ speed, therefore the frame time chart looks good miraculously. And you, the user, will have to deal with input delay.
For me, an AMD cards and a 3rd party FPS cap software is the best. No input lag, no stuttering. And the image quality from AMD is always superior.
wow, it’s spot on data, tough
wow, it’s spot on data, tough to take in, especially if you purchased Radeon’s since the begining but it is true.
but GOD People – stop with the flaming!!!.
AMD will have to do a hardware re-do to fix this, i don’t really expect anything to come out for a year. i don’t really think that anyone misled on purpose – this is all new testing data.
AMD still makes an ok card- but the issue is with multiple cards.
answer- don’t buy multiple lower cost cards with AMD
I wish you’d start testing
I wish you’d start testing with newer drivers. They have 314.22’s out, had 314.21 out, and even a 314.07 all in WHQL, but you’re still on beta .07’s? I think they even had a 314.14 whql in there.
Many games have been optimized since then. Great data, just want later Nv drivers as you’re a few behind at best.
https://www.youtube.com/watch?v=gQ3U2P8ZLz4
15% for 314.07 vs. 314.21 in tomb raider, others show basically the same and in some cases more and this was on an old 9600GT card…LOL. Who knew?
Sorry for the huge review,
Sorry for the huge review, computer repair in schaumburg but I’m really loving the new Zune, and hope this, as well as the excellent reviews some other people have written, will help you decide if it’s the right choice for you.