AMD Radeon HD 7990 Review: Dual GPU Comeback

Julio Franco

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[newwindow=https://www.techspot.com/review/663-amd-radeon-hd-7990/]https://www.techspot.com/review/663-amd-radeon-hd-7990/[/newwindow]

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Frame latency is an interesting measurement. Do you also bench latencies of different inputs in LCD panels?
 
What a monster of a card, but I'm totally not jelly, don't have the money for at $1000 GPU setup. =p

Also, I think the Temperature chart on page 8 is mislabeled as a second power efficiency chart. =o
 
Someone please explain how the card is consistently clocking better FPS than xfire'd GHz cards? Internal connector better than external...?

The test bench mobo supports x16 lanes on both PCI-E slots, so it's not this...
 
Someone please explain how the card is consistently clocking better FPS than xfire'd GHz cards? Internal connector better than external...?

The test bench mobo supports x16 lanes on both PCI-E slots, so it's not this...

Not sure if consistently is the best word to describe it. The 7990 was slower in Tomb Raider and Resident Evil 6 by 6%, 5% slower in Far Cry 3 and 3% slower in Medal of Honor while the performance in Max Payne 3, DiRT 3 and Crysis 3 was the same. It was only 1% faster in Battlefield 3 and Sleeping Dogs (so you can call that the same) while the only game it was actually faster was Hitman Absolution. So by consistently you mean one game :)
 
Frame latency is an interesting measurement. Do you also bench latencies of different inputs in LCD panels?
Apples and oranges comparison. For a start, display latency is constant and shows itself by input lag, while GPU latency shows up by stuttering and inconsistent frame rates due to widely inconsistent frame rendering.
An extreme example here:
cfx_jpeg.jpg

While the average for tri-crossfire looks pretty good, the actual user experience paints a different story:
With AMD Radeon HD 7970 GE 3-way CrossFire we had a very bad experience in this game. It wasn't so much to do with raw performance as it was extremely bad stuttering. It was terrible, taking into account the game's natural stuttery behavior and combine that with the inconsistent framerates we experience with CrossFire equaled a horrible experience in this game
 
Steve 1% is 1%, I know it's very close (and probably in the realms of testing anomalies) but it's still 1%. The GHz card can even boost, so this is why I'm surprised the 7990 clocked better at ALL. :O
 
Steve 1% is 1%, I know it's very close (and probably in the realms of testing anomalies) but it's still 1%. The GHz card can even boost, so this is why I'm surprised the 7990 clocked better at ALL. :O

1% is certainly well within the error testing margin so it's not really any different from the other tests where the 7990 and 7970 GHz CF cards delivered the same performance. Again there was only one game where the 7990 was genuinely faster, why that was isn't exactly clear. Most likely do to the 7990 using a slightly newer driver.
 
AMD should have solved the crossfire latency issue first and then released this card. May be AMD is getting ready for their 8000 series. The game bundle coming with this card is extraordinary from AMD. I like the back plate, Nvidia should include those things in their high end cards(atleast). Nvidia is making a lot of profit compared to AMD.
 
Another excellent review but I have one question to ask:
Why did you test sli 660s? I was expecting to see sli 680s because that is the "single card configuration" for the 690 which is the direct competition of the 7990, the dual card configuration of the 7970.
 
Another excellent review but I have one question to ask:
Why did you test sli 660s? I was expecting to see sli 680s because that is the "single card configuration" for the 690 which is the direct competition of the 7990, the dual card configuration of the 7970.

Unfortunately we don’t have an endless treasure trove of graphics cards, if we had a second GTX 680 handy we would have included SLI results. The GTX 660 Ti SLI cards were included because … you guessed it we had two :)

It is very hard to get as many high-end graphics cards as we do and hold onto them, getting two is all the more harder. Still you have the GTX 690 there so it shouldn’t be all that difficult to work out where a pair of GTX 680’s would be sitting on those graphs.
 
Steve, all the games used in the test have great scaling under dual gpu solutions. Did you already know that beforehand and, therefore, conducted the tests or was it it just a happy coincidence?
My point is: are there really that many games so well optimized out there so that we can consistently expect that kind of scaling ?
 
Steve, all the games used in the test have great scaling under dual gpu solutions. Did you already know that beforehand and, therefore, conducted the tests or was it it just a happy coincidence?
My point is: are there really that many games so well optimized out there so that we can consistently expect that kind of scaling ?

Certainly with AAA titles yes. These days Crossfire and SLI support is common and most games are supported, most quality games that is.
 
I'm still impressed with how 660ti's in SLI perform.They're consistently right up there competing with the top cards despite costing half as much.
 
Unfortunately we don’t have an endless treasure trove of graphics cards, if we had a second GTX 680 handy we would have included SLI results. The GTX 660 Ti SLI cards were included because … you guessed it we had two :)

It is very hard to get as many high-end graphics cards as we do and hold onto them, getting two is all the more harder. Still you have the GTX 690 there so it shouldn’t be all that difficult to work out where a pair of GTX 680’s would be sitting on those graphs.
I understand and I appreciate the clarification. I'm just a little interested/biased towards seeing those results because I have 680s in sli :)
 
I totally would be jealous if crossfire was better than SLI. But until AMD can get equal or better performance from their Xfire I will be sticking with Nvidia. So no jelly's here haha.
 
Coming back and forth from AMD and Nvidia I totally understand frame latency now. It's pretty obvious on AMD in most games. The new drivers that Nvidia released yesterday are supposed to push fps in popular games even more.
 
It's no secret that my personal loyalties are with Nvidia. Over the past 5 years GTX's have been smoother cards with more features/less problems. It was nice to see the 7970 have the success it did but I still never considered it the single GPU king during that period because it came with an asterisk; it never definitively beat the 680 outright and still it loses stock for stock in games.
7970 owners are only fooling themselves with thier performance claims...these results are devious and don't represent the stuttery gameplay or frametime results. Simply put, they are not as good as GTX's and never were.
They are bang for your buck GPU's and that has not changed.
A GTX is the best GPU money can buy and offers the smoothest, most feature rich gaming experience money can buy. Period.
 
Well, that about settles it.

I'm getting two 660 TI's for SLI. As someone mentioned above it is surprising that these two cards perform almost as well as the $1,000 cards and cost several times less.
 
Well, that about settles it.

I'm getting two 660 TI's for SLI. As someone mentioned above it is surprising that these two cards perform almost as well as the $1,000 cards and cost several times less.

Why would you do that 1 680 would do better and I got news for you a lot of games don't work right with crossfire or sli
Don't think that 2 cards are better than one look at benchmarks and you will see 1 680 will beat out 2 660ti.
 
Well, that about settles it.

I'm getting two 660 TI's for SLI. As someone mentioned above it is surprising that these two cards perform almost as well as the $1,000 cards and cost several times less.
Because, the 660Ti is a 680 with disabled cores, TMUs, and ROPs. It performs on par because it happens that some games are good at scaling. That is not true for a lot of games. With crossfire and SLI, there is a higher chance of graphical corruption. Fbarnet is right in that aspect, but a 680 is a better option because it can play most games on highest settings @ 1080P. If you arent playing on >1080P, dont SLI.
 
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