5870 temperatures & fan speed

[cupkakes]

Hi Folks,

I've recently flashed the BIOS on two of my 5870s and set their clocks & memory to 950MHz and 316MHz respectively. Of course this makes them run a little hotter, though due to the positioning of them, the second card severely restricts airflow to the first... My first card is sitting at 82C and the second is at 62.5C - is running at 82C on a 24/7 basis too hot?

Also, currently the fans are on auto - but they do get a bit faster if I set them to 100% and of course this makes the temperature drop a bit. My question is, is it worth running the fan at 100% to lower the 82C? Or will 100% speed on 24/7 spin my fan into an early grave?

Cheers,
Cupkakes

[MasterHunterHD]

I think that making the cards run at 82C 24/7 won't damage your card straight away, but it will eventually slow down in time...
I would do this, I would maybe increase the clock a bit, but only make it run like 12-15 hours a day.

As well as, the fan will loose performance and effectivity in time if they run very fast for a long time.
Let the fans go on Auto. If they need more cooling the computer will know when to put more effort.

[pbj sammich]

I had the same issues. On my mb the first 2 pci-e slots were just too close together so I moved one of the cards. I'm now at about 76 and 62 respectively.

To your situation I don't think 82 is all that bad. Sure could be better but its not horrible. Heck I had my first card run at around 91 for 3 weeks without a hitch until I got some better fans.

I would set the fans manually probably. I have both my cards fans set to 65% and that seems to keep the temps consistent.

[MasterHunterHD]

I had the same issues. On my mb the first 2 pci-e slots were just too close together so I moved one of the cards. I'm now at about 76 and 62 respectively.

To your situation I don't think 82 is all that bad. Sure could be better but its not horrible. Heck I had my first card run at around 91 for 3 weeks without a hitch until I got some better fans.

I would set the fans manually probably. I have both my cards fans set to 65% and that seems to keep the temps consistent.

I think you're right. But you know, I wouldn't strain the cards too much...

[pbj sammich]

it makes you wonder why the ATI reference cards have the only fan positioned where it is going to basically sit right on top of the second card in most motherboards....

[cupkakes]

Thanks for the advice guys, I have since installed a 3rd card (decent enough PSU finally arrived) and this pushed temperatures up even more, though I overcame the restricted airflow problem with a very no-frills solution...
http://img593.imageshack.us/img593/5697/20110625171440.th.jpg
...clothes pegs!

Wedging a wider gap has helped loads now, no more 80C+ temperatures. The cards are running at:
66C [960MHz core, 320MHz mem] = 425MHash/s
72C [950MHz core, 316MHz mem] = 420MHash/s
78C [905MHz core, 301MHz mem] = 400MHash/s

To be honest I was only aiming for 1GHash/s, but the bit of MacGyver has boosted me to 1.25GHash/s - well chuffed!

[gpubitcoin]

82 degrees is too hot on a 24/7 basis. Drop the overclocks or find better cooling, else you will shorten the life of your cards.

[shata]

I run set fan speeds, Keep my 5870 and 6970 between 80-90C , Normally that needs 65-75% fan speed.

[mautobu]

Really, the best way to mine on those cards would be to throw some LN2 in there and clock them up to 1300/300 @ 1.4v

[cupkakes]

Really, the best way to mine on those cards would be to throw some LN2 in there and clock them up to 1300/300 @ 1.4v

Perhaps not as cost effective to run though