I cannot recall what it was in Windows 7 exactly, but it was much less than 500us. In Windows 8, it never drops below 1000us.
I measured the DPC Latency using the DPC Latency Checker (http://www.thesycon.de/deu/latency_check.shtml).
Any idea why this is? Immature drivers? (Specs in the sig btw)
Attachment 7761 (http://www.eightforums.com/attachments/f1/f28/7761-why-dpc-latency-high-windows-8-dpclatency_win8.jpg)
This is...