Overclocking and Noise
Be it teething troubles or process limitations or whatever, finding the limits of the reference board didn't take long. With the same GDDR3 modules as our NV40 reference board - Samsung's GC16 GDDR3 variant - the memory overclock was guessable.With a starting core clock of 520MHz and the GPU produced on a process that has a generally accepted limit of 600MHz for complex GPUs like R420, the core overclock wasn't going to be huge.
Here's the final clock able to be set in PowerStrip without causing visual problems or artifacts in our overclocking test, two loops of 3DMark03.
Overclocking Results
R420 seems to scale with core and memory clock quite similarly to NV40. It seems to scale well with simple core clock increases, moreso than memory clock increases.
Noise
The fan adjusts speed based on temperature, slowing down to a barely audible noise when in Windows or doing light 3D. At full speed it's somewhat noisy, but no more so than the NV40 reference cooler and definitely quieter than an ASUS 9800 XT cooler at full fan speed.Subjectively excellent, the slower fan speed in 2D mode contributing to that.
