Cpu usage + lower sandra score

[mare87]

I have just purchased Winfast A 6600 GT TDH AGP 8X.
I am very satisfied with it`s performance but I have encountered a minor problem:

I had the Abit Siluro GF4 TI 4200 64mb agp 4x graphics card and 44.03 software drivers. My CPU usage (at idle) was at constant 0 % and my Sisoft Sandra Memory bandwith bechmark score was 3450.(+/- 5)

After installing this graphics card my CPU usage (at idle) went up and it is constantly switching between 2 and 4%, scarcely dropping to 0 %. I had installed drivers that come on the CD (66.93), I tried Nvidia`s 66.93 and also 67.03. Before installing the card I have uninstalled previous display drivers, nforce drivers (control panel + safe mode) and even with the help of Nasty File Remover and Driver Cleaner, but nothing worked. It was (is) still using my CPU in idle.
What can be the problem? Is the temperature monitoring in drivers using the CPU?
Note: I changed NONE of the specs before installing the new card.
Besides that I found out that at one time the cpu usage was back to normal... and I`m wondering what`s the problem. I also checked out the event viewer and found out that "nv" drivers are switching between Silent Running: Stress test transition: L0 -> L0. What`s up with this?

Specs: ABIT NF7S 2.0, bios d26 manta rays xt (modded)
chipset: nforce 2 400 ulta
nforce drivers: Mwarhead remix rebirth 3.31 a
display drivers: 66.93 from Nvidia

[endo]

Heres what xbit had to do to get

[mare87]

What ? In this time, I have figured out that when the monitor turns off and then on CPU usage stays at 0% and the memory score is ok.