Want to supercool a Radeon 8500
 

I plan to cool the GPU and the rams on the same side with a single custom-shaped cold plate that is cooled by an 80 watt peltier. I want at least 25-30 watts of cooling for the rams, so do you think an 80 watt pelt is enough for both GPU and 4 rams? I will have another cold plate with a 55 watt peltier on the other side cooling the rams. Both pelts are cooled by water. Now the question is how much voltage to feed the core and mem because it will be hard to pencil once I've insulated the card? If I were to use variable resistors to tweak the voltage, what pots should I use? Do I just put the positive end of my multimeter to one resistor and the negative to another to measure the voltage? I dunno if this is true but is the core higher in height than the mem?

the pelt sizes you've listed are about right, and everything else seems fairly accurate. I'm not sure about the voltages though.

for the coldplate the major problem is that the ram and gpu are at differant heights, this prooves to be a major issue for many people

maybe u could mod the cold plate to diff thick nesses where needed

thats the hard part hehe. getting that the right height differance, and level

Hmm, look at http://www.zerofanzone.co.uk/ Bladerunner's Radeon. Is his base different height, or is his Radeon's GPU and ram the same height?

direct link http://www.zerofanzone.co.uk/picture...8500dsmall.jpg

no, they are at different heights. what you do tho, is get a thin sheet of copper, and epoxy that on top of the RAM chips (thus bringing the RAM and GPU to the same height). then just put your cold plate or whatever on top of that.

I think i've found a way to cool both sides of the ram with a single pelt. Been looking through some aluminum sheets today. So my plan would be to pelt the GPU solely with an 80 watt, and pelt the rams with a 55 watt.

You cant use variable resistors... they have 2W ratings unless you get a HUGE 55W variable resistor. Even rheostats have lower ratings than that. A 50W rheostat costs $30. Your best bet would to build a voltage regulator circuit with some high wattage variable regulators and a big heatsink, and use the pots to trim the regulators. Or just find a psu that puts out a desirable voltage for your TEC's.


Heh, nevermind... i thought you were tweaking the TEC's voltage... long day.

well, bladerunner says on his site: "A one piece unit stepped so it contacts both ram and GPU with combined channeling, and relief holes for the capacitors near the ram chips."

this makes me think he took care of the different hights on the plate.

--Matt

thats a nice block then :D