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Cathar · 02-06-2003, 07:38 PM

I have personally found that it helps to not have any ramsinks at all when using a strong peltier on the GPU core.

Why? Because the ram chips are located very close to the GPU core, and are connected by tons of metallic traces. These conduct enough each to chill the memory down quite substantially.

For example, I did an experiment on a GF3Ti200 with a water-cooled 80W peltier. The card at best would do 240/540 stable using air-cooling alone. With the peltier on top, the card was hitting 280/590 core/mem, and the ram chips, which had no heatsinks on them, were cool to the touch, even under full load. Sticking heatsinks on the ram chips is the wrong way to do things. You're now giving extra surface area for the ambient air to heat the ram chips back up again. If anything, you want to be insulating them from the air, and let the peltier do its job by drawing the heat away via conduction through the card PCB.

The extra heat that the peltier adds to the water system is just something that needs to be dissipated by the radiator. An 80W peltier at 12v adds something like 120W of extra heat to the system, which for a largish radiator like I use, means maybe 2-3C higher water temps (and therefore CPU temps) depending on how hard I run the radiators fans.

02-06-2003, 07:38 PM	#8
Cathar Thermophile Join Date: Sep 2002 Location: Melbourne, Australia Posts: 2,538	I have personally found that it helps to not have any ramsinks at all when using a strong peltier on the GPU core. Why? Because the ram chips are located very close to the GPU core, and are connected by tons of metallic traces. These conduct enough each to chill the memory down quite substantially. For example, I did an experiment on a GF3Ti200 with a water-cooled 80W peltier. The card at best would do 240/540 stable using air-cooling alone. With the peltier on top, the card was hitting 280/590 core/mem, and the ram chips, which had no heatsinks on them, were cool to the touch, even under full load. Sticking heatsinks on the ram chips is the wrong way to do things. You're now giving extra surface area for the ambient air to heat the ram chips back up again. If anything, you want to be insulating them from the air, and let the peltier do its job by drawing the heat away via conduction through the card PCB. The extra heat that the peltier adds to the water system is just something that needs to be dissipated by the radiator. An 80W peltier at 12v adds something like 120W of extra heat to the system, which for a largish radiator like I use, means maybe 2-3C higher water temps (and therefore CPU temps) depending on how hard I run the radiators fans. Last edited by Cathar; 02-06-2003 at 07:44 PM.