Radeon HD 7990 In CrossFire: The Red Wedding Of Graphics

[bucknutty]

Sounds silly but I wonder if a $10.00 PCI intake fan would help. If it were to be installed in between the 2 cards it would pull cool air from the back of the case and blow it on the hot spot. It would also act as an air break to prevent an type of vacuum issue where the lower card is starving the upper card for air.

I would have made a cardboard divider to see if providing an air break would help with the hot spot.

 

[Hando567]

I can't personally comment on 2x 7990s, but I am currently running a 7990 and a 7970 in 3-way crossfire, and I have no such issues using all air cooling in my HAF XB. Using custom fan ramps in afterburner (basically just puts fans at 100% past 60C) I manage to keep all 3 GPUs running below 70C, which I personally don't think is too bad.

Chris, did you try running them with the case side off just to see where the temps would get in a test-bench sort of setup to find out if it would work at all? It seems strange that you are having so many thermal issues when my 3 GPU setup runs so cool (comparatively).

 

[xzendor]

A Very Informative Article And Eye Opener.

 

[ojas]

So i guess only liquid cooling would work?

 

[internetlad]

I truly can't imagine why you would need, at this point, two or more 7990s other than for bragging rights. My 7950 maxes most games, so unless you're looking to run the Firestorm 3dmark benchmark and brag about your crazy FPS I don't see the practicality behind this.

That being said, That's like putting an engine from a 2 ton truck in your rat rod, then being suprised when your axle snaps. This is a job for water cooling, plain and simple.

 

[bystander]

@Patrik Eskelinen?

There original article on the 7990 included video of the cards to compare noise:
http://www.tomshardware.com/reviews/radeon-hd-7990-review-benchmark,3486-15.html

 

[bystander]

I truly can't imagine why you would need, at this point, two or more 7990s other than for bragging rights. My 7950 maxes most games, so unless you're looking to run the Firestorm 3dmark benchmark and brag about your crazy FPS I don't see the practicality behind this.

That being said, That's like putting an engine from a 2 ton truck in your rat rod, then being suprised when your axle snaps. This is a job for water cooling, plain and simple.

Not everyone plays on a 1080p monitor. In 3-5 monitor setups or 4k monitor setups, people might want this sort of power.

 

[ojas]

I truly can't imagine why you would need, at this point, two or more 7990s other than for bragging rights. My 7950 maxes most games, so unless you're looking to run the Firestorm 3dmark benchmark and brag about your crazy FPS I don't see the practicality behind this.

That being said, That's like putting an engine from a 2 ton truck in your rat rod, then being suprised when your axle snaps. This is a job for water cooling, plain and simple.

Why do you need a Mclaren F1 when a Civic does the same job (getting from point A to B) just fine?

 

[geok1ng]

You are doing it wrong. very few enthusiast wouls spent USD 2000 on 2 7990 to run on air. And the experiment used a PC case that, IMNSHO, is not ideal for the thermal challenge. Vertical motherboard placement is key to the sucess of the experiment, with intake fans in bottom of case and exaust on top using convetion and VGA aligment to dissipate hot air. http://www.silverstonetek.com/product.php?pid=242&area=usa. Silverston FT02 FTW.

 

[cangelini]

You are doing it wrong. very few enthusiast wouls spent USD 2000 on 2 7990 to run on air. And the experiment used a PC case that, IMNSHO, is not ideal for the thermal challenge. Vertical motherboard placement is key to the sucess of the experiment, with intake fans in bottom of case and exaust on top using convetion and VGA aligment to dissipate hot air. http://www.silverstonetek.com/product.php?pid=242&area=usa. Silverston FT02 FTW.

Tell that to Falcon (and check out the picture on page three) 😉

 

[lesteron2]

They tried to do too much smart stuff and screwed some of it up.

 

[Michael Wolfe]

I can see why there's heat build-up in the top GPU near the IO bracket. And the reviewer is correct in his assumption: It's a cyclonic vacume.
First, you have a sideways-jetison of heated air from the heatsink. Provided the fans are slightly angled to push slightly more air away from the mainboard, you still have some hitting the mainboard regardless. This is why I dislike heatsink designes like this; they are great for single-card confirguations. However, in dual-card configurations you have the lower card channeling the heated air directed at the mainboard back up in front of the upper card's fans. Presuming standard airflow within the chassis, there is a soft push from the front of the cards to the back IO bracket which helps keep the second GPU on the top card cooler, but not by much. Considering it's own heat is compounding with the heat cycled from the primary GPU near the IO bracket, it's a double-hit on the GPU. The ONLY way you could do a reliable test of this, is to either install a directed-airflow fan to channel air through them and remove the slot brackets for venting; or instead use a supplemental dedicated blower fan between the cards to act as a supplemental exhaust. Otherwise, you're looking at liquid-cooling them outright. Any of these three solutions will fix this.

 

[de5_Roy]

Wow man how much does Nvidia pay you ?

nvidia doesn't pay me anything. i was just pointing out the events as they happened.

edit:
frame pacing driver update: july 31st.
http://vr-zone.com/articles/amd-promises-to-fix-crossfirex-with-driver-update-coming-july-31st/39843.html
it wasn't june after all. just 51 more days.

 

[geok1ng]

Tell that to Falcon (and check out the picture on page three) 😉

Page Three shows an ICON2, that is most likely how Falcon names the Raven 01 from Silverstone. There is only 1 fan below the VGAs. FT02 has 2 fans. The same picture, when compared against your own picture makes one think that Falcon was placing the 7990s only one slot apart instead of 2 slots.

The whole point seens moot and i do agree that most of your conclusions and recommendations are correct. AMD must show us a real life system, using an unmodified case from the qualified CF list that works with 2 7990s.

 

[sourodip]

amd could have gave the beast some better cooling

 

[InvalidError]

amd could have gave the beast some better cooling

Three low-profile fans re-ingesting their own exhaust in such a tight loop definitely does not look like a particularly bright idea. Things like that really need better-structured airflow that minimizes the amount of re-ingested exhaust.

 

[sourodip]

amd could have gave the beast some better cooling

Three low-profile fans re-ingesting their own exhaust in such a tight loop definitely does not look like a particularly bright idea. Things like that really need better-structured airflow that minimizes the amount of re-ingested exhaust.

+1
they should have made it more perfectly after taking so much time.
What the hell are u doing AMD?

 

[geok1ng]

a 10cm Crossfire conector, to space the cards 3 slots apart helped this guy complete some benchs on quad fire months ago.
http://www.kitguru.net/components/graphic-cards/zardon/hd7990-quadfire-tested-crash-happy/

 

[bystander]

a 10cm Crossfire conector, to space the cards 3 slots apart helped this guy complete some benchs on quad fire months ago.
http://www.kitguru.net/components/graphic-cards/zardon/hd7990-quadfire-tested-crash-happy/

That is not the same card as the one tested here. That was one of the custom cards made last year, not the AMD reference card recently launched.

 

[geok1ng]

That is not the same card as the one tested here. That was one of the custom cards made last year, not the AMD reference card recently launched.

Still that is another valid idea in what is already becoming a desperate attempt to actually test how quad fire works on this generation, if at all:

*FT02
*10cm crossfire connector
*sheet of carton/plastic to completely isolate the cards airflows
*send the test bed to New Zealand South Island or Chile

Googling previous quadfire attempts with 7990s basically shows 2 situations:
-It was done with watercooling
-The reviewer faced unsolvable crashes

Which means that when AMD claimed that 7990s can be crossfired on air they were most likely referring to tests performed during Moscow's last winter.:lol:

 

[eddieroolz]

The more testing is done on the 7990, the more it begins to sound like AMD's past dual-GPU efforts - rushed and underengineered.

Though as Chris noted in the end, NVidia is not free of the waste heat issue either, but fact we haven't heard much regarding heat issues in quad-SLI with GTX 690 suggests that the heat issues in NVidia cards are at least managed better.

It's a shame really, because AMD produces amazing single-GPU cards. 7970 is available in Canada for $349 which is downright amazing.

 

[arief_sujatmiko]

I think AMD should have tested all of their product in their labs for a few days, and never use media reviewer as their tester, or maybe they should hire third party tester for their hardware and base their test on real world games and applications and ensure nothing is wrong and working at best for user experience...

 

[06yfz450ridr]

hmm if you have enough money for 2 7990s you have enough money for a nice 480mm rad liquid cooled loop to keep them decently cool

 

[sourodip]

AMD should have give more cooling and attention for their 7990 and not rushed to release to counter the gtx690.
Hope they will make better 8990 with better cooling.

 

[17seconds]

AMD should have give more cooling and attention for their 7990 and not rushed to release to counter the gtx690.
Hope they will make better 8990 with better cooling.

Hard to say they rushed the release of the 7990. It came out a year after the GTX 690 and a full 16 months after the release of the HD7970.

Those facts and the resulting product really speak volumes about the internal research and development processes at AMD. Their internal organizational model needs to be reconfigured (and there is evidence that it is) before anyone should expect a dramatic improvement in terms of aesthetics for the 8990/9990 over the 6990/7990. Big question, though, how much is console development stealing resources from the desktop graphics development team?