Sign in with
Sign up | Sign in
Your question
Solved

Higher idle temp with Crossfire set up? Also spacing?...

Last response: in Graphics & Displays
Share
August 11, 2012 6:45:26 AM

Evening folks,

I ventured into the realm of adding a second video card to my rig. First attempt ever doing an upgrade like this.

Everything is up and running and Crossfire is enabled. I haven't tried out any games yet, I just got done installing the software for the 2nd card.

I am running dual HD 5870's.

Just wanted to ask a couple questions about some things I noticed. My idle temp. went from about 38 c.(when I was running one card), now it sits at about 45 c. Is this normal to have a slight jump in idle temp when adding a second card?

Second question is with regard to the spacing. I have the HAF X Coolermaster case. My motherboard supports a total maximum possible of three video cards. I am utilizing two slots out of three obviously.

I did not expect that the cards would be as close together as they are. I am using two adjacent slots(the UPPER two), with a metal stabilizing bracket spacer in between(that came with the case), which provides additional support and is keeping the cards from sagging downwards under their weight.

Now the WEIRD thing about my ASUS motherboard is that the third video card slot(the BOTTOM slot) looks like you can't fit a card in because there is a whole row of cables connected along the bottom edge that appear to block right where the third card would be. So I used the two upper slots.

I am using the correct spacing, I mean you can't put the cards in any other way, it's dictated by them having to have their ports sticking out through the back cutouts of the case, which you have to allign to.

Basically what I'm asking is, are the cards designed to be THAT close together when you use neighboring slots? My cards right now have about a quarter inch in between them. Both cards have fans on the bottom, so the top card's fan is largely blocked from air flow, but can still spin obviously. If I was to ever "Triple Fire" with a third card, they'd be sitting right on top of eachother with tiny slivers of space in between. How do the other video cards get enough air flow when their fans are blocked off by the next card being up against it?

Are the cards designed to be that close together? Doesn't ventilation become an issue? The HAF X case has plenty of fans, I'm running five case large fans(two for intake, and three for outtake), and each card has its own fan of course.

I just wanted to make sure I did this right, and if I might need any additional cooling besides the fans I have.

Thanks in advance, sorry for the length of my post!






Best solution

August 11, 2012 11:31:32 AM

In my setup, the top card (card who's airflow is blocked by the card just below it) runs hotter. Even the edition of a side fan does not cure this (might help a bit though.)

In my case, there's at least one slot open between the cards. So there's some room for air to move, but airflow is CLEARLY worse off for the one card (you can monitor either card in your system to see the difference.)

I have seen photos of PCs where there was no slot between the cards. In that case, I am not sure how the airflow works, unless the card is designed to push air behind it, towards front of case.

I have a HAF case to, not sure of the model. But the number of fans would seem irrelevant...it's the specifics of the airflow off the GPUs that is going to matter.

Seems without liquid cooling or some clever DIY engineering with fans, you are going to have hotter video cards with crossfire than without.

I thought about sticking a few 80mm fans on top of both cards to blow air into the gap between them just to see if I could push out air faster from the top card.

Share
August 18, 2012 8:25:16 PM

michaeljhuman said:
In my setup, the top card (card who's airflow is blocked by the card just below it) runs hotter. Even the edition of a side fan does not cure this (might help a bit though.)

In my case, there's at least one slot open between the cards. So there's some room for air to move, but airflow is CLEARLY worse off for the one card (you can monitor either card in your system to see the difference.)

I have seen photos of PCs where there was no slot between the cards. In that case, I am not sure how the airflow works, unless the card is designed to push air behind it, towards front of case.

I have a HAF case to, not sure of the model. But the number of fans would seem irrelevant...it's the specifics of the airflow off the GPUs that is going to matter.

Seems without liquid cooling or some clever DIY engineering with fans, you are going to have hotter video cards with crossfire than without.

I thought about sticking a few 80mm fans on top of both cards to blow air into the gap between them just to see if I could push out air faster from the top card.


Hello Michael,

Thanks for taking the time to write back to share your insights, I really appreciate it!

Your setup helps to give me a clearer picture of how this all works. It would SEEM, after reading your feedback and others, that even with a huge gaming case with plenty of overall case ventilation, it still comes down to the problem of the spacing of the slots on the d**n motherboard. It also seems that, as you said, the only real way to address heat with a second card is to add additional cooling in the form of more fans or a liquid rig.

I believe you are 100% right about the number of case fans. In this situation, more case fans doesn't help you because the card itself simply can't shed enough of the hot air immediately around it that it's generating during use. No matter how fast the case fans move warm air out of the case generally, the card still can't push heat away from itself fast enough. The heat builds up in the small space between the upper and lower card, and there's no opportunity for cooling.

I'm kind of shocked that with today's technology, they wouldn't making gaming motherboards with this whole problem in mind! Why on earth would they skimp on spacing when it comes to one of the hottest running components? All they would have to do is make the motherboard a few inches longer, and add a little more spacing between GPU slots. I don't get it.

I would suspect therefore that a good number of gaming rigs that use multiple video cards have a liquid cooling unit added. With three card setups....?.....lol...I'm not going to venture there, I'm mechanically challenged enough managing TWO cards.

Mike, I don't know if you've seen these, you probably have - but I ordered one of these and I'm installing it on my top card:

http://www.amazon.com/Zalman-VF3000A-Dual-Bearing-Coole...

This is essentially in line with your reasoning and your idea of adding a couple 80mm fans to the top card, which is basically all that this unit does. It's gotten really good reviews, and installation is fairly straightforward. However it does require that you take the top slice of the card off and expose the fiddly bits, which always makes me nervous. It also involves, if I'm not mistaken, exposing the heat sink and checking and applying new thermal paste if necessary. BUT, with that installed, it will ensure that the card will now have cooling both above and below, and heat will have an outlet upward into open air just as the bottom card has an outlet into open air.

What I'll do is, after I get the cooler installed, I'll report back here and tell you how many degrees the card drops in idle and under load, and if the difference is significant. I suspect it will be.

Of course, an easier solution still would be to abandon Crossfire altogether and just not deal with it, and upgrade to a faster, newer single GPU. My problem with that is, I'm trying to get a stable rig that I can game with for MORE than six months at a time before I have to upgrade anything. I mean it's insane! My rig is only a year and a half old! I've got 12 Gigs of memory, an i7 processor, an ASUS gaming motherboard(ok, 2009 technology but it's still damn good), a 1200w power supply....and people are saying I need to upgrade everything! I can't afford to do that. I don't have the money to be upgrading mother boards every year and a half. I can't gut my case every year just because something faster has come out. I have to think about longevity and using what I've got.

Thanks again.

m
0
l
August 18, 2012 8:27:38 PM

Best answer selected by oinkusboinkus.
m
0
l
!