Hello MagicAndre & friends, I join this thread hoping you can help me improve my DPC latency. Back in XP SP3, DPC latency used to stick around 40-50 µs. Within win7 64, I don't have huge red spikes often, but yellow ones (1070 µs for example) happen quite easily, and overall my latency is in the 300-400 µs range, which feels too much and uncomfortable : this is supposed to be a fully functionnal DAW for me to earn a living with it. Xperf shows an unknown module and it's function 0xfffffa8002fb20f0 which i suspect is reponsible for the situation. Please find with this post a .txt summary of my PC http://www.zshare.net/download/76065675ce27aac1/ a screen shot of DPC latency checker a screen shot of xperf's Summary table http://www.zshare.net/download/76065675ce27aac1/ Best Regards.