High latency with MSI 790XT-G45 under W7

Question

I have decided myself to go for W7 one one of my rigs.I ve got some genuine disks of 32 and 64 and loaded W7 for testing purposes .
As my intention is to use the 790XT-G45 (considering it more W7 suited than my Platinum beeing newer more CPU support) tryed both W7 versions , but there is a problem.
Using the DPC high latency tool i get like 100 us under any W7 version with this 790XT-G45.The same board is ok latency wise under XP ,it hovers around 10-20 us when you re not doing anything serious with it .I have to remind that on this board i ve also had some issues with the big mouse cursor thing that seems to be related to motherboard latencyes.
In the past i ve used the K9A2 Platinum with W7 64 RC with the same video card and sound card that i use now on the 790XT-G45 ,but the latency was always 10-20 us.In fact trying again the Platinum gives me under W7 like 10-20 us.
I ve  tryed disableing onboards ,removing the Creative and updating to latest BIOS version but no joy.The latency also adds some drag to the system i mean W7 windows don t look to snappy like it feels on Platinum.
So is this board compatible to W7 for real ?
What is so different between the 2 boards ,does the 790X have bigger latencyes than the 790 FX from the Platinum.One of the issues is that even if i would choose the Platinum  CPU upgrade path closes.
I repeat i ve tested both boards with default W7 drivers and with vendors drivers and same thing.
Any user with 790XT-G45 encountering this under W7 ?
At first glance it s not a very big issue ,but i m very sure this 100 us get s me while playing to more and i really hate input lag and static on my sound.
Any ideas ?

Answer 1

Hi Guys,
I agree with Sm3K3R that a 70+ microsecond increase in average DPC latency will have an undesirable affect on some apps (games, real-time streaming, etc.). I also believe that what is good for XP will almost certainly not be good for Windows 7. Too much of the architecture has changed. Better drivers may help going forward. To me, the bigger question is why this mobo takes so much longer to run these routines than the K9A2.
I do not have any serious problems with the apps I run. Some of them may run better with a shorter average DPC latency. I have no way to tell with what I currently have to work with. Other bottlenecks may be in play. I was just responding to Sm3K3R's request for feedback. My power option is set to high performance and my base configuration has 41 processes running, including Diskeeper real-time defragmenter, Avira Antivirus, Logitech SetPoint, Process Lasso's process governor, PeerBlocker, and TaskDock. It also includes the Microsoft search functions and the sidebar with 2 gadgets running. Most of these processes run as services. I thought it was the search, sidebar, or one or more of the non-Microsoft products causing my base 100+ average latency indicated by the DPC high latency tool, so I ran LatencyMon to find out.
I ran it several times for 2 to 5 minutes at a time, starting when the system was idle. The Nvidia display and NT Kernel & System drivers always topped the list, with latencies from 50 to 114 microseconds. The display driver's routine also ran much more often than any thing else, followed, about 60% less often, by the NT Kernel & System driver. Thus these 2 drivers contribute the most to my average DPC latency. The other products listed above most often had 0 or less than 15 microsecond DPC latencies. Once I saw this, I did not bother to check my game configuration which does not have the search, sidebar, and the non-Microsoft products listed above in it.
During a Google search of this issue, I read that someone reduced their average Windows 7 DPC latency by 50 microseconds by turning off the HPET timer. I tried this and it did not work for me.
Looking forward to the results of Sm3K3R's further testing and feedback from others.