I recently upgraded my system to Windows 7 64bit from Windows XP 32.

I performed a fresh install of Windows 7 on a separate hard drive.

While I was in Windows XP I never had DPC latency spikes and my DPC latency was around a really healthy 3-4?S.

After installing Windows 7 64bit I am experiencing huge DPC latency spikes that seem to be caused by the RME driver. I have installed the latest 3.085 driver.

Here are the specs of my PC:

DAW: Gigabyte EX58-UD5, Intel i7920, 12GbRAM 1600Mhz, 750W Corsair PSU, nVidia 9400GT Silent, RME Multiface II PCI-E, Cubase 5.5, W7 64bit

What I did try:

I disabled all the network adapters.

I disabled all Firewire adapters (TI by the way).

I tried installing the latest graphic drivers from Nvidia.

I tried disabling all the Windows 7 visuals like Aero etc

None of these worked. Finally, I came to the conclusion that there is something going wrong with my RME because the last thing I disabled was RME Multiface from the Device Manager. When I did that the DPC spikes stopped!

If I boot Windows XP I still get the same great performance, but in Windows 7 the spikes just seem to come out of nowhere.

They do not seem to affect the audio performance at buffers like 256 but they do affect it in lower buffers when tracking.

Is this a known problem with the 64 bit drivers? I would appreciate any help,  please let me know if you need any additional information.

Thank you in advance!