"It's a Senfu!"
(Water cooling a Celeron, and why you should care)

I grabbed some readings from System Health Monitor: 18ºc. I wouldn't trust this at all, because I was once told my cpu was at 27ºc just after I burned my fingers on it. Then I got down to some benchmarking.

WCPUID@366

WCPUID@550

SANDRA CPU bench @ 366

SANDRA CPU bench @ 550
SANDRA CPU MM bench @ 366
SANDRA CPU MM bench @ 550
SANDRA Memory bench @ 366
SANDRA Memory bench @ 550

The temp at 550 hangs around 20ºc most of the time, but that's according to System Health monitor. Memory benchmarks at 550 don't properly reflect the speed increase, because for some reason the system won't get through the POST screens at CAS2.