You're not the only one with this problem. I don't know what the difference between the 9.5.4 and 9.5.6 drivers is but whatever Intel have done it's introduced terrible DPC latency problems in 9.5.6 resulting in bad video & audio stutter. Back to 9.5.4 the problem goes away.
Taken me hours of diagnostics, fiddling & reboots to pin it down to the driver. (using dpclat & xperf)
Similar system to yours: Intel Core i7 , Gigabyte GA-EX58-UD5, 3 GB Corsair, four Western Digital Raptor 36Gb drives (Raid 5), ATI 1900 PCI-e video, Creative Sound Blaster X-Fi (software version). Windows 7 (64bit) Ultimate
Message was edited by: Bobins
Thanks Bobins for confirming my observation, at least for your config. From the amount of attention I was being given in the main RST 9.5.6 thread, I was beginning to think I was imagining the whole thing :-)
I don't know if it's just me, and gigabyte boards, but I always get DPC latency issues if I'm using the default Vista/7 power plan..
EP35-DS4 (BIOS F6) - Win7 x64
and EP45-UD3 (BIOS F9) - running Vista x64
I don't know if it's cosmetic or what.. but the minute I change Vista/7 to "High performance", suddently DPC latency disappears.
I currntly run my system in "High Performance" mode all the time and I've tried disabling all the bios "power saving" options one-by-one.
The only thing that made a difference was going back from 9.5.6 to the 9.4.6 drivers.
I suspect that something Intel is doing to improve the SSD compatibility of the software is moving it away from supporting some combinations of motherboard and mechanical drives. (a SATA 1 support isue perhaps?)