After installing the latest driver, a lag in response as result.

After using the 190.38 driver, I installed the latest,
257.21. In the the meantime there are already later versions.
I experience quite a lag in response from the mouse, keyboard (a little) and the screen is sluggish. (But not slowed down, responce is quite normal.)
Also using CUDA 3.1 drivers. (I'll have a look with Process Explorer).
(When I want to look with Google Eath, a game, video, I've to disable the GPU for a while). Luckily, this can be done from the status bar, right and Right-click disable GPU. Have a Dutch version, so I'm not sure what's text on your U.S. BOINC's)
It's plowing through an incredible amount (>300 Einstein WU's for CPU only and CPU+GPU (1 CPU core))
Don't notice any speed gain. They don't use a lot of it's full potential, 1280GDDR5, 40 ROP's and 448 Shaders, a 320BIT PCI_Ex16 bus, used O.S. is WIN XP64,
4GByte DDR2 (5.5.5.15;1T)800MHz;FSB:DRAM=5:6; QX9650@3200MHz(atm)
CPU. For the 470 a 30A at +12V is needed.
I'll post a link to some GPUz screenshots.