Think before going Crossfire (or SLI)

[Mo5]

This will be one educational story... learn from my mistakes  :)

So...

March 2011 I was buying a new PC. I didn't have much money (800€) and obviously wanted the highest performance I could get. That's why I went the AMD route and got a Phenom II X4 955 :) and since I already had a HD5750 (Powercolor, 1GB) I decided the best way to go is CF. I picked up a Sapphire HD5750 to go with my old card along with a bunch of other components:

Asrock 890GX Extreme 3

Arctic Cooling Freezer XTREME Rev.2
4GB Kingston HyperX
Samsung Spinpoint F3 1TB
Chieftec APS-750
Cooler Master HAF912 PLUS

Now when choosing any part I do thorough reading of reviews and the 890GX Extreme3 was getting good reviews so since it was in my price range I decided to get it... and this was a mistake I now regret. Don't get me wrong, it's a good mobo, but not for CF for the reason I'll explain with this picture:

Look at how the PCI slots are layed out. There's a one PCI-e 1x then there's a blue PCI-e 16x followed by PCI and that by another blue PCI-e 16x slot. Below that there is are 2 PCI slots and a white PCI-e 16x (4x electrically) slot. I think you can see where this is going.

After building the PC and installing everything I decided I wanted to play some games. And like every other enthusiast does I too monitor the temps of my components. That's when I noticed that the temps of the GPU0 (upper GPU) are getting out of control - over 95°C. Until now, I just cranked the fan up to 100% and hoped for the best, but that was noisy and probably ruining my fan slowly.

Today I put the bottom card two slots lower in the white slot, making it a 16x/4x CF config and tested it out. The problems with the top GPU were gone - it reached 75°C MAX... but it introduced a new, bigger problem. The bottom gpu was now too close to the PSU and thus rising the temps dangerously. Too dangerously - max. 115°C.

That's why I went back to the 'safer' 8x/8x set up. 

 

There you go kids. Before going with a multi-gpu set-up carefully study the layout of all the components (and PCI-e slots) 

 

[nightlitezzz]

I don't get it. I haven't read much about CFX or SLI tbh. Why did putting your cards in 'x' slot make it run hotter?

[Mo5]

I don't get it. I haven't read much about CFX or SLI tbh. Why did putting your cards in 'x' slot make it run hotter?

general position in the case. it first ran hot because the bottom gpu was blocking the airflow for the top gpu, when I moved it down, the PSU was blocking the airflow for it.

[Milta]

@nightlitezzz Because they are on top of each other, so they don't get enough airflow and is some situations blow hot air onto each other. If you can space them out it's generally better, but in his situation he couldn't.

 

You beat me to it Mo5 :D

[orangecat]

This isnt a problem with SLI/crossfire its called a user who doesn't know what they are doing and what did you do to make your cards get so hot even a overclocked card shouldn't get that hot in a system with half decent ventilation. also if you psu gets hot enough to heat your gpu to 115C get a new psu.

[Tardbarn]

I don't think it has much to do with running the cards in certain slots, I think it has more to do with running the cards in closer proximity to one another. If I'm understanding what you read correctly, your top GPU ran cooler when you spaced them out more, but then the bottom one was too close to the PSU which introduced a new heat problem for the bottom GPU.

 

I think the problem is more to do with the cards being too close to components that create heat, in this case, it seems its a trade off between the two GPUs being too close to one another or the bottom GPU being too close to the PSU.

I doubt the temps are that high due to running the cards at 8x/8x vs 8x/4x, or whatever your case is.

 

With my dual 670s, the top card never goes much above 80C, but...they are completely different cards.

[laxer]

I have a different problem although somewhat similar.

 

I have 2 6970's in my system, if you don't know they are fairly large cards.

 

The first(top) card goes in without any problems however, due to my Sata headers being set inside the board versus on the edge like in the OPs board I could not install the second without removing the sata cords.

 

My solution ended up being that I needed to buy right and left angle cords and plug the bent ends into my board to allow for enough clearance.

 

As always plan ahead and you will be fine.

[Mo5]

I don't think it has much to do with running the cards in certain slots, I think it has more to do with running the cards in closer proximity to one another. If I'm understanding what you read correctly, your top GPU ran cooler when you spaced them out more, but then the bottom one was too close to the PSU which introduced a new heat problem for the bottom GPU.

 

I think the problem is more to do with the cards being too close to components that create heat, in this case, it seems its a trade off between the two GPUs being too close to one another or the bottom GPU being too close to the PSU.

I doubt the temps are that high due to running the cards at 8x/8x vs 8x/4x, or whatever your case is.

 

With my dual 670s, the top card never goes much above 80C, but...they are completely different cards.

You've explained it a bit better :)

[nightlitezzz]

Now I feel dumb, I misinterpreted your post.  :lol:

[Tardbarn]

You've explained it a bit better :)

 

I must admit my friend, I do sympathize. Before I added my second GTX 670, my computer would be inaudible while gaming. Now I have the slightly high frequency whine of the 92mm fans of my GPUs accompanying my gameplay, which is....unfortunate. I might have to invest in a silence optimized case. 

[laxer]

I must admit my friend, I do sympathize. Before I added my second GTX 670, my computer would be inaudible while gaming. Now I have the slightly high frequency whine of the 92mm fans of my GPUs accompanying my gameplay, which is....unfortunate. I might have to invest in a silence optimized case. 

 

Or drop a few waterblocks on those bad boys!  :D

[SubTract]

I would do this

 

White represents your Graphics cards

Green = Move all HDDs into bottom cage

Red = Remove this HDD Cage

Yellow = Install a directional airflow fan such as Noctua NF-F12's or

 

Blue = Install a conventional high air flow fan here (On side panel)

 

Best thing about HAF cases is they can move A LOT of air.

 

A fan exhausting out the top if you want to neutralise the pressure.

 

Then your temps should drop significantly

 

Edit: I should just say If they're the cards I'm thinking they are then you would want that side fan to exhaust. I've not seen a 5750 with a blower design cooler. If it is a blower design then use the side fan as intake.

[donfrodini]

I would do this

 

 

White represents your Graphics cards

Green = Move all HDDs into bottom cage

Red = Remove this HDD Cage

Yellow = Install a directional airflow fan such as Noctua NF-F12's or Silverstone Air Penetrators 

Blue = Install a conventional high air flow fan here (On side panel)

 

Best thing about HAF cases is they can move A LOT of air.

 

A fan exhausting out the top if you want to neutralise the pressure.

 

Then your temps should drop significantly

 

I would try this I have the same case running SLi 670's temps on the GPU's are at 30c idle and 70-75max under load. I have two exhausts one at back (which is a corsair H80 watercooler running exhaust) and exhaust at the top at the back. I also have another cooler at the top pulling air in incluing all the fans mentioned above pulling airflow into the case.

 

My CPU is running mid 20's at idle up to around 60c at load with an overclock of 4.4GHz (i53570k). To me it sounds as though you need to adjust the airflow in the case, if that fails then you deffo need to invest in a new MOBO., though personally I cant see ASRock making such an oversight as they must assume many people will be running SLi.

[Nexus]

Its a common problem. The top card pulls in warmer air so the temps are also higher.

Its nothing to worry about though its normal and expected and AMD/nVidia take this into consideration when designing the cooling system for the cards.

 

Also try it with 7970s. Extremely loud and extremely hot.

[YellowDragon]

Its a common problem. The top card pulls in warmer air so the temps are also higher.

Its nothing to worry about though its normal and expected and AMD/nVidia take this into consideration when designing the cooling system for the cards.

 

Also try it with 7970s. Extremely loud and extremely hot.

Its typically better to go with the reference design coolers if you plan to xFire or Sli just for this reason, Custom Cards dont typically take a multi-gpu setup into consideration as they are a very small percentage of users, this can lead to unforeseen temperature problems if you dont have proper case ventilation. From the OP's post it sounds more like a problem with a proper case ventilation more than anything else

[GamerDude]

Bah, that's nothing, I have my 3 cards lined up one on top of the other, the top and middle cards run hottest. And yet, having my fan at 70%, my temps maxed out at about 80C.......never in the 3 figure range, and my cards generally run hotter than the OP's.

[SubTract]

I would try this I have the same case running SLi 670's temps on the GPU's are at 30c idle and 70-75max under load. I have two exhausts one at back (which is a corsair H80 watercooler running exhaust) and exhaust at the top at the back. I also have another cooler at the top pulling air in incluing all the fans mentioned above pulling airflow into the case.

 

My CPU is running mid 20's at idle up to around 60c at load with an overclock of 4.4GHz (i53570k). To me it sounds as though you need to adjust the airflow in the case, if that fails then you deffo need to invest in a new MOBO., though personally I cant see ASRock making such an oversight as they must assume many people will be running SLi.

 

The problem is generally less prominent with blower design coolers.

As most of the hot air is exhausted out of the case. Only incidental heat off the back of the PCB or Backplate getting drawn in through the top card.

Having a water cooled CPU should prevent excess heat in your case also, This would also effect your temps.

[SubTract]

Bah, that's nothing, I have my 3 cards lined up one on top of the other, the top and middle cards run hottest. And yet, having my fans @704w%, my temps maxed out at about 80C.......never in the 3 figure range, and my cards generally run hotter than the OP's.

What;s the scaling like on 3 cards?

[Nexus]

Its typically better to go with the reference design coolers if you plan to xFire or Sli just for this reason, Custom Cards dont typically take a multi-gpu setup into consideration as they are a very small percentage of users, this can lead to unforeseen temperature problems if you dont have proper case ventilation. From the OP's post it sounds more like a problem with a proper case ventilation more than anything else

Yeah. I know some people run a reference card at the bottom and a custom card at the top, that way most of the heat from the bottom card is ejected out the back and the top card stays cooler due the better design of the aftermarket cooler. If you use an aftermarket cooler at the bottom the warm air just gets blown around rather than ejected.

 

I really don't understand how he can be reaching 95oC and 115oC with 5750s, they aren't exactly hot running cards if irc.

 

OP just a suggestion but try swapping the cards around. It could be the cooler on one of the cards is not properly mounted.

[YellowDragon]

What;s the scaling like on 3 cards?

 Not very good, I run a quadfire 7970 setup and I see performance gains in this way (listed in order of effectiveness from 0-100% per card)  1st card: 100%, 2nd Card: 75% 3rd Card 20% 4th card 0-5% (or goes into negative scaling) past two cards its really not cost effective and 2 cards can handle anything out there, I did my quadfire setup for the bragging rights and the looks, I know that I dont gain much performance from my 3rd and 4th cards, but dont really care cause im happy :D

[Tardbarn]

Or drop a few waterblocks on those bad boys!  :D

 

Yeah, I would absolutely love to, but I can't take the risk at the moment of damaging my computer since I rely on it for school work as well. 

[SubTract]

 Not very good, I run a quadfire 7970 setup and I see performance gains in this way (listed in order of effectiveness from 0-100% per card)  1st card: 100%, 2nd Card: 75% 3rd Card 20% 4th card 0-5% (or goes into negative scaling) past two cards its really not cost effective and 2 cards can handle anything out there, I did my quadfire setup for the bragging rights and the looks, I know that I dont gain much performance from my 3rd and 4th cards, but dont really care cause im happy :D

You know why????

CAUSE I MOTHER FRACKIN' CAN!

 

:D I know that feeling.

[YellowDragon]

You know why????

CAUSE I MOTHER FRACKIN' CAN!

 

:D I know that feeling.

Only complaint is that my air conditioner gets overpowered when I game due to the immense heat output.

[7850OC]

what can i say... 7990  :D

[FluffyNuggets]

Wanna know how to solve that from happening? Have intake fans on the side door blowing air between both cards. It also helps having a intake fan underneath the bottom card.

Honestly, people should never go SLI if they have bad airflow in their case.