Radeon HD 7990 In CrossFire: The Red Wedding Of Graphics

[jtd871]

I don't know why cards like these just don't come with factory-installed waterblocks as the 'stock' option. Cooling this much power on air is just silly, as water has 4 times the specific heat capacity of air and watercooling will not turn your entire chassis into an oven. Air cooling these monsters should be the 'enthusiast' option.

 

[InvalidError]

A full GPU article without any benchmarks, just for dissing AMD. Tom's continues with the good ol' bias.

Not much point in going through benchmarks when the drivers have known stutter/pacing issues that would ruin benchmark results anyhow.

The point of this mini-article wasn't performance; it was that dual 7990s with reference coolers appears to have fundamental thermal design problems on top of deficient drivers.

 

[de5_Roy]

New Zealand was out before Malta, just never official, but unlike most Dual GPU's it was an experiment at putting uncapped top line GPU's on a single PCB, but clearly the power demand moreover the heat is to high for fully fledged Tahiti XT cores to be thrown on at once.

New drivers will release soon so the point is moot.

Nvidia drivers, the ones that saw a vastly superior GTX680 at launch end up around 10% slower than the 7970 after new catalyst drivers. To me the only thing AMD are doing wrong is releasing sea Islands in such close proximity to Volcanic Islands early next year but can't say you are not spoiled for choice.

7990 drivers may be out afaik. that's not the one what i was talking about.
the frame pacing driver (i.e. the one that was supposed to be the first step in improving/delivering smooth gameplay experience) had been needed since the first week or within the first month 7970 came out. the proper software support has been long overdue. june's not over, so we'll see if amd keeps their word. just in case, last week/day of june would be technically within june but that'd be uncool imo.

the only things amd doing wrong are:
neglecting and/or being late with software support.
poor timing of launch.
poor treatment to newly launched cards.
chronic denial of persisting issues.
and more as you dig deeper.
these have driven potential amd multi-gpu customers to gtx titan.

 

[cmartin011]

Why they can not fix micro stutter is beyond me. They are in the business of making micro architecture design them to work properly together. As for the heat that boggles my mind. Under clocking the boards just for the 4 gpu benefit should have been tried. Just for shits and giggles throw a floor fan or air conditioning unit on the side of the case blasting air on the gpus. I would just get some unpractical benchmarks lol

 

[ubercake]

...
7990 drivers may be out afaik. that's not the one what i was talking about.
the frame pacing driver (i.e. the one that was supposed to be the first step in improving/delivering smooth gameplay experience) had been needed since the first week or within the first month 7970 came out. the proper software support has been long overdue. june's not over, so we'll see if amd keeps their word. just in case, last week/day of june would be technically within june but that'd be uncool imo.

the only things amd doing wrong are:
neglecting and/or being late with software support.
poor timing of launch.
poor treatment to newly launched cards.
chronic denial of persisting issues.
and more as you dig deeper.
these have driven potential amd multi-gpu customers to gtx titan.

My sentiments exactly. This is what drove me to Nvidia in the first place. I really hope they get it worked out. I want a truly competitive market with choices darn it?!

 

[panzerknacker]

In order to make it work, and to be able to perform benchmarks with the tripple card setup, why don't you go to the local junkyard and pick up a automotive fan (the one behind the radiator) and hook it up. These things blow such an insane amount of air that I'm sure the system will be fine that way, and you should be able to hook em straight up to the PSU because they run on 12v, just make sure you have some watts left. I know this is not a solution for a real world situation where you would be using the system in a office or something, but atleast you can perform benchmarks that way.

Maybe you just need insane cooling, more insane than what is commercially available for computers ^^

 

[sarinaide]

From my experiences the HD7990 with watercooling is perfect, but like any dual GPU its for high rollers only. As for software support AMD's drivers are fine and the frame pacing issue will be sequentially fixed in a series of drivers due out by AMD for first Sea Islands then Volcanic Islands releases, people are just so damn impatient.

My opinion of people's issue with writer bias is more that every AMD deficiency or issue is under the microscope while you would find other companies get let of rather unscruitinized. While its a reviewers obligation to bring it to light, it sometimes ends in a 4 page tirade that really ought to have been one.

 

[ubercake]

From my experiences the HD7990 with watercooling is perfect, but like any dual GPU its for high rollers only. As for software support AMD's drivers are fine and the frame pacing issue will be sequentially fixed in a series of drivers due out by AMD for first Sea Islands then Volcanic Islands releases, people are just so damn impatient.

My opinion of people's issue with writer bias is more that every AMD deficiency or issue is under the microscope while you would find other companies get let of rather unscruitinized. While its a reviewers obligation to bring it to light, it sometimes ends in a 4 page tirade that really ought to have been one.

Why are people to be considered "so damn impatient"? When we spend $1000+ on GPUs, we expect them to work as advertised (damn consumers and their expectations!).

Why is that wrong?

 

[sarinaide]

From my experiences the HD7990 with watercooling is perfect, but like any dual GPU its for high rollers only. As for software support AMD's drivers are fine and the frame pacing issue will be sequentially fixed in a series of drivers due out by AMD for first Sea Islands then Volcanic Islands releases, people are just so damn impatient.

My opinion of people's issue with writer bias is more that every AMD deficiency or issue is under the microscope while you would find other companies get let of rather unscruitinized. While its a reviewers obligation to bring it to light, it sometimes ends in a 4 page tirade that really ought to have been one.

Why are people to be considered "so damn impatient"? When we spend $1000+ on GPUs, we expect them to work as advertised (damn consumers and their expectations!).

Why is that wrong?

So based on charts that can still be themselves fictional you don't think the HD7990 works and that everyone that owns one is up in arms about it percievably "not working". We haven't had any returned for failures due to thermals. We have been told by those that bought reference cooled cards that they had heat issues but nobody expressly complained about throttling in games or bitmining.

Wait on the new driver roll outs, I have been told that AMD will have around 3-4 quickish roll outs of new drivers that will focus on crossfire improvements and along with single GPU improvements, the Beta already exhibited massive frame latency improvements so thats a positive step is it not.

My opinion of people's issue with writer bias is more that every AMD deficiency or issue is under the microscope while you would find other companies get let of rather unscruitinized. While its a reviewers obligation to bring it to light, it sometimes ends in a 4 page tirade that really ought to have been one.

AMD's microstutter issues, and the thermal problems exhibited here, are not things you need a microscope to see. Nvidia simply doesn't have problems this catastrophic. Also to be fair, I believe Nvidia does not claim to officially support quad-SLI - not 100% sure though.

Nvidia's problems have less to do with what the end user actually winds up experiencing (e.g. no real voltage control on their cards, board partners on a short leash with what they can/cannot do, etc) and so they don't show up as problems in reviews.

Again its generalised, not every end user is having these issues, that said most buyers in this segment are taking watercooled options, that is from what we have sold. As for these unplayable frame rates, it is much like when Toms told me my A10 5800K was incapable of playing games well with a HD7970 because it was percieved to be incapable, now we have APU iGPU's beating i3's with HD6670's and APU's running off low latencies in benchmarks all over. Much has changed and perceptions are fallable.

 

[ubercake]

From my experiences the HD7990 with watercooling is perfect, but like any dual GPU its for high rollers only. As for software support AMD's drivers are fine and the frame pacing issue will be sequentially fixed in a series of drivers due out by AMD for first Sea Islands then Volcanic Islands releases, people are just so damn impatient.

My opinion of people's issue with writer bias is more that every AMD deficiency or issue is under the microscope while you would find other companies get let of rather unscruitinized. While its a reviewers obligation to bring it to light, it sometimes ends in a 4 page tirade that really ought to have been one.

Why are people to be considered "so damn impatient"? When we spend $1000+ on GPUs, we expect them to work as advertised (damn consumers and their expectations!).

Why is that wrong?

So based on charts that can still be themselves fictional you don't think the HD7990 works and that everyone that owns one is up in arms about it percievably "not working". We haven't had any returned for failures due to thermals. We have been told by those that bought reference cooled cards that they had heat issues but nobody expressly complained about throttling in games or bitmining.
Wait on the new driver roll outs, I have been told that AMD will have around 3-4 quickish roll outs of new drivers that will focus on crossfire improvements and along with single GPU improvements, the Beta already exhibited massive frame latency improvements so thats a positive step is it not.
...

Positive steps, but not ready for prime time. Yeah... I won't sink my dollars into that promise.

For the benefit of us consumers, I really hope AMD puts it all together. Since I do use multiple GPUs, I'm tired of not having a choice in the market.

 

[sarinaide]

You need a framerate limiter with crossfire. The only people not experiencing stutter with crossfire on high end systems are people who use vsync/framerate limiters or people who have way more GPU muscle than they need (e.g. running two 7970s on a single 1080p monitor or people playing games that just aren't very demanding) so their framerates are so high that stuttering is not noticeable.

Watercooled 7990s would obviously not have the temperature issues, but I don't see AMD saying "hey by the way you need to watercool these to use two of them". They should just take the route Nvidia takes and say "this may work but we don't officially support this".

Perceptions may be fallible, but data isn't, and the data on some of this stuff shows that AMD has some real work to do with their multi-GPU solutions.

The only fair criticism you can level at coverage of crossfire's issues is that almost no reviews take the time to test a framerate limiter and mention that you can mitigate most stuttering issues by using one.

AMD did say they and we all know they are working at it, that is driver side when it comes to multi GPU, multi monitor systems. Nvidia being for most a GPU designer alone have had the benefit of focusing resources and time into drivers for that but it doesn't mean AMD are neglecting it.

As for thermal, my only assumption is based on AMD's bold approach to the 7990, Full Tahiti XT cores with no caps or restraints is something nobody has done and the power needed is really high but it is not without the gambles to achieve the performance capable from these cards. In compute muscle these cards are not even in Nvidia's radar at this point with the HD7970 decimating every Nvidia option to date, in gaming sense they are faster than the 690 and Titan overall bar frame trasition issues, the performance is there and AMD have achieved what they where looking for in that regard but as aforementioned it is not without teething issues but these are not absolute barriers.

 

[ddpruitt]

I wonder if your problem here is far simpler. The fan setup isn't stock here and I'm wondering if the PSU is pulling rather than pushing air out of the case. If so it could cause the airflow to stagnate and can cause some rather nasty overheating problems. This would cause any card to fail regardless of make or model.

I've seen a number of cases were moving the orientation or location of a single fan paid tremendous dividends. Perhaps this is the case here?

 

[JPForums]

I would love to see pictures of the setups you used trying to track down the problems. The HAF-X employs two parts specifically for helping get air to the correct locations.
1) On the side fan, there is a shroud that can be turned to a better direction to keep your cards fed.
2) There is an internal fan + shroud that can be mounted on the motherboard side of the HDD rack that can funnel air from the front fans to the graphics cards.

A third point of consideration is that the PSU should probably be mounted with the fan on the bottom in this setup. There is a filter on the bottom for just such a setup. As it is, the PSU is taking air away from the bottom GPU.

I have tried these changes. They do make two 7990s usable (still pretty toasty though). Unfortunately, you have to buy the fan that goes into the shroud mounted off of the HDD rack and you may need to mod the shroud to get it to fit, depending on your specific cards and motherboard. However, there is no call to save an extra $10 - $30 when dropping $2000 on video cards. I recommend the higher rpm noise blockers.

@Twoboxer Yes, the FT02 should be able to keep them under control, ..., or at least keep them from having a meltdown. (Verified against a Raven RV02-e). Keeps them cooler than the HAF-X, though not by much.

Note: My tests were done in a basement where the ambient temperatures were generally 66F. To be fair, the ambient temperatures didn't stay their once these puppies got turned on. Too, bad I couldn't keep the cards as I was building for a client. Though, he did let me keep the HAF-X chassis when he decided to go with the Raven RV02-e. The GPU cooling was a little better, but I think the kicker was that he could use the exhaust at the top of the RV02-e for a hand warmer.

 

[JPForums]

Nice and detailed read, I would wonder how they went if you had a side fan on the case (or did I miss that this test did have that)?

I assumed they had as it would provide air directly to the GPUs, but now I'm wondering. One of the writers her at Tom's Hardware did champion the use of negative pressure systems a while back. While it was the correct choice given the chassis they used, that was more due to the fact in the chassis they selected, it was better at putting the airflow where it was needed. However, in a situation such as this, negative airflow setups show their weakness, as they can pull air away from the places they are really needed (creating a vacuum). When you have so many fans fighting over air, it is important to keep an abundance of air available. In my experience, assuming you can get the air where it needs to go, positive (or at least less negative) pressure systems work better in this situation.

Updated: It appears they did as they mentioned the Coolermaster default setup when trying to explain the low exhaust temperature relative to the GPU temperature. Also, it occurs to me that you may have been asking about an external fan pointing at the chassis or a box fan blowing directly into the chassis. I'll bet the box fan as a side panel idea would probably work. Really, AMD shouldn't be selling cards that require expert knowledge in thermal engineering just to get normal (supported) usage out of. A simple, only use this version stand alone, or use a water block (or perhaps external exhaust) version for crossfire would have saved them a lot of trouble.

 

[fwupow]

Is there a liquid cooling solution for these cards? Some sort of 7990 water-block out there? Is AMD destroying ATI now?

 

[sarinaide]

Is there a liquid cooling solution for these cards? Some sort of 7990 water-block out there? Is AMD destroying ATI now?

Yes there is and ATI don't exist so no they are not and why do you assume AMD is destroying anything...data it is the fastest solution bar teething issues.

 

[hesskia]

It's amazing that this article came out when it did---I'm having the exact same problem with a pair of 7870's in crossfire (XFX Double D and MSI R7870-2GD5T/OC). No matter what I've tried, the top card consistently reaches thermal throttling at 102°C. The MSI Card seems to do better than the XFX Card though. When comparing the two, the MSI card exhausts out the rear panel while the XFX card exhausts into the case. Keeping space between the cards seems to double the time it takes to throttle.

I've went back and forth with XFX without much luck. They sent me a new HSF, which still exhausts into the case, and it didn't resolve my issue.

 

[Isaiah4110]

Very interesting read. If, as the article theorizes, the top card is creating a vacuum then wouldn't the best method to verify (and possibly resolve) that issue be to "inject" some air into this area of the case?

What if one were to remove the case covering between the two cards and add a small fan (likely centrifugal) to the outside of the case blowing air into this open slot? It would definitely make for a very odd looking rig, but I would be very interested to see the results. Another option to a centrifugal fan would be a standard case fan mounted to a funnel that channels air into the open slot.

 

[cangelini]

I would love to see pictures of the setups you used trying to track down the problems. The HAF-X employs two parts specifically for helping get air to the correct locations.
1) On the side fan, there is a shroud that can be turned to a better direction to keep your cards fed.
2) There is an internal fan + shroud that can be mounted on the motherboard side of the HDD rack that can funnel air from the front fans to the graphics cards.

A third point of consideration is that the PSU should probably be mounted with the fan on the bottom in this setup. There is a filter on the bottom for just such a setup. As it is, the PSU is taking air away from the bottom GPU.

I have tried these changes. They do make two 7990s usable (still pretty toasty though). Unfortunately, you have to buy the fan that goes into the shroud mounted off of the HDD rack and you may need to mod the shroud to get it to fit, depending on your specific cards and motherboard. However, there is no call to save an extra $10 - $30 when dropping $2000 on video cards. I recommend the higher rpm noise blockers.

@Twoboxer Yes, the FT02 should be able to keep them under control, ..., or at least keep them from having a meltdown. (Verified against a Raven RV02-e). Keeps them cooler than the HAF-X, though not by much.

Note: My tests were done in a basement where the ambient temperatures were generally 66F. To be fair, the ambient temperatures didn't stay their once these puppies got turned on. Too, bad I couldn't keep the cards as I was building for a client. Though, he did let me keep the HAF-X chassis when he decided to go with the Raven RV02-e. The GPU cooling was a little better, but I think the kicker was that he could use the exhaust at the top of the RV02-e for a hand warmer.

I meant to add a comment on this as soon as the story went up, but just for reference, I tried reversing fan directions, changing fan speeds to alter air pressure levels, and using/removing the ducting. All told, there was less than one minute's different in the time it took for two cards to hit 102 degrees in Heaven.

 

[chumly]

SIMPLE SOLUTION: Spend another $1000 on water cooling! Money fixes everything!

 

[JPForums]

I meant to add a comment on this as soon as the story went up, but just for reference, I tried reversing fan directions, changing fan speeds to alter air pressure levels, and using/removing the ducting. All told, there was less than one minute's different in the time it took for two cards to hit 102 degrees in Heaven.

You certainly put a lot of work into it. Doesn't seem like you can fix the problem with the standard options available to you. Out of curiosity, though, did you try the (HDD mounted) ducting with or without a fan? The chassis doesn't come with one, but one can be added to the duct. Curiosity aside, it almost sounds as if there is a problem specific to the card itself, (heatsink obstruction, poor heatsink contact, etc.). Did you get the same thermals in the same spot if you swap the retail cards? I'm imagining you've already explored this line of thought to no avail, but sometimes people (or just me) forget the obvious.

 

[slippyrocks]

you're doing it wrong
the power supply intake should be facing down, the way you have it it is pulling hot air straight to the bottom of the case
here is the stock fan configuration and orientation HAF-X was certified for:
Front: 230x30 mm red LED on / off fan x 1 blowing in
Top: 200x30 mm fan x 2 (one optional) blowing out
Side: 200x30 mm fan x 1 blowing in
Rear: 140x25 mm fan x 1 blowing out
VGA Fan Duct: 120x25 mm or 120x38 mm fan x 1
VGA Holder:80x15 mm fan x1

 

[bdiddytampa]

Nice read, was wondering why I hadn't seen more of these setups out there, money issues aside...

 

[redeemer]

let's see...
the frame pacing driver that amd said would be available in june, isn't available yet.
7990 came out over a year after 7970.
7990(reference cooler) has problems.
dual 7990(reference cooler) have even more problems.
titan has high demand, enough to outsell dual gpu cards.
nvidia has better drivers as of now.
nvidia let gtx690 sell for a year before launching titan and gtx780 while improving drivers further (and before making fcat available outside *wink*wink*).
oh.. i forgot about the free games. free games always make problems go away....
.... nicely done, amd. :lol:

i like tahiti(gcn) and it's performance. don't like the injustice amd's doing to gcn based cards. 🙁

Wow man how much does Nvidia pay you ?

 

[JPNpower]

Dear Santa...
Your home is about to melt from global warming. Maybe you should skip this one for the holidays.

Cheers!
Nature