Thesycon's DPC Latency Checker is a Windows tool that analyses the capabilities of a computer system to handle real-time data streams properly. It may help to find the cause for interruptions in real-time audio and video streams, also known as drop-outs. The program supports Windows 2000, Windows XP, Windows XP x64, Windows Server 2003, Windows Server 2003 x64, Windows Vista, Windows Vista x64.
DPC Latency Checker for Windows 2000, XP, XP x64, Server 2003, Server 2003 x64, Vista, Vista x64
Download dpclat.exe V1.1 (310 KB)
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I found recently pretty high DPC CPU usage on my R2H with Vista when copying things onto external USB drives or copying file from it over wireless. This tool won't tell you much more than Process Explorer, although they do suggest a trial and error aproach to find the offending device driver. I believe RATTV3 doesn't work on Vista or I couldn't get any information from it anyways. I'll keep investigating this hopefully finding a fix soon...