How much cooling is necessary for 4850 ram?

mrred

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Dec 19, 2005
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The topic is self-explanatory!

I am being a cheap-ass so I'll find a way to rig my maze4 waterblock onto the gpu.

Will the card work with no ramsinks at all? I'm assuming no...

If I do put ramsinks (cheap ones) on, will I need to also have a PCI slot fan in order to keep air moving over the 'sinks?

Thanks for any help from those with experience with this card!
 

error8

Diamond Member
Nov 28, 2007
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The card will work just fine without any heatsinks on the ram chips. But you should have a fan blowing over them, since you're water cooling the card and there's no air flow at all over it. Of course, putting heatsinks will further improve the heat transfer.
 

QuixoticOne

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Nov 4, 2005
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Everything I've heard is that good case airflow AND at least moderately good RAMSINKS are pretty essential for proper temperatures on the RAM chips.

I don't know if a PCI slot fan is the best bet. Maybe if it is a nice one and actually blows (not sucks) air pretty directly over the RAM sinks. Otherwise I'd suggest modding the case a bit to add one or two 80mm fans to blow more directly over the ramsinks / card, or use an 120mm in some position if that works best for your case, whatever.

 

mrred

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Dec 19, 2005
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Thanks for the advice.

I came to the realization that the power management area will also get very hot and it won't be covered by the gpu block.

Seems that even if the ram can handle no airflow, the PWM certainly won't.
 

Sylvanas

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Jan 20, 2004
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The Mosfets are designed to operate at 125c you generally do not need to have sinks on them if you have good airflow. Same goes for Memory IC's- it may be preferable to have sinks on them though. Personally I do- just because it has boosted my OC by quite a bit in the past. See if you can buy some Swiftech MC14's or the Ezotech copper ramsinks.
 

QuixoticOne

Golden Member
Nov 4, 2005
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To the OP, yes, you're right, get some good cool strong airflow over the PWM areas as well as the ramsinks.

Sylvanas,

Some MOSFETS may be rated to an maximum operating JUNCTION temperature of 125C, yes. However reliability / lifetime is compromised significantly at this temperature compared to running them 50C cooler if possible. Temperature vs. lifetime is an exponential function.

Also you're not understanding that it is quite possible / normal for the JUNCTION temperature of a power MOSFET to get up to 125C or whatever its maximum is WHEN the case has a heatsink / heat spreader and good TIM and is cooled by good airflow. They push these things to the limit in many cases, and that is assuming you DO all the proper cooling / heatsinking / airflow. If you have poor cooling / heatsinking of the case and bad airflow you're likely to have the fets get above 125C internally in very many cases.

I'm an EE, I design this sort of stuff.