Replace stock 5870 heatsink with a CPU heatsink?

[Guest]

So I've been reading that people have been using (modding) water coolers such as the Antec Kuhler H2O 620 to cool their GPU's. How viable is this as an option? I just bought the 620 for $35 bucks with rebate. Would it be worth it to use it on my GPU, or maybe use the stock Intel i5-2500k one on my GPU? I actually have them in crossfire so cooling them both isn't an option due to space constraints.

How much FPS improvement do you actually get from overclocking 5870's with stock coolers? Is overclocking even worth it?

EDIT: I think about 5 fps is worth it if it doesn't damage your GPU or reduce the lifespan any.

 

[fallen17754]

overclocking will always reduce the lifespan, not by much though, you'll probably upgrade your card by the time it gets anywhere near dying. overclocking is somewhat worth it to get 1-5 fps increase usually, dont go above a 20% oc to be safe imo, keep temps under 80C, use msi afterburner to OC, i recommened to not mess with the voltage unless you know what you're doing and set a custom fan profile at 40% fan speed 24/7. i personally wouldnt bother modding a water cooling on that card. use that watercooler you got on your cpu and get rid of the stock intel fan. if you have 2 5870's i wouldnt bother ocing them honestly if you're getting 40/45+ fps in the games you play id suggest to leave your cards alone.