DPC Latency Checker

[ha14]

Hi

DPC Latency Checker measures the response time of your system. The response time is influenced by any other application that is currently running on your system. For an accurate result, we recommend you to close all applications before launching DPC Latency Checker. If you run this tool while there are applications open you will notice that, while you close them, the results will improve.

The greatest problem when moving to a computer from analogue recording devices is that of latency.

For example, device drivers are high-priority tasks that need to be processed right away before any other task. If a device has an improper driver this operation is going to take more time than usual and it's going to slow down the system which will lead to interruptions in real-time audio and video streams.

Latency is the inevitable delay between the computer receiving audio information and then playing it back. This problem is greatest when trying to record additional tracks to a song.

The length of delay varies greatly between computers and the software and device drivers installed on them. DPC Latency Checker is a tool for checking how bad the latency of a computer is, and can then be used for troubleshooting.

The checker can be left running while changes are made to the computer to see if they improve the situation

Every 50-60 seconds the DPC latency spiked to about 16ms. Since most professional audio software requires absolute low latency at all times, this DPC spikes will result in audible skips in those high-performance audio programs.

The reason why this spikes happen every 60 seconds or so is that, when enabled, Vista is actively scanning and detecting available wireless network and managing wireless network profile. The service responsible for this is called ‘WLAN AutoConfig Service’ which is similar to ‘Wireless Zero Configuration service’ in XP.

Since this service is required in order for us to establish a wireless conection, we cannot just disable it.

Unfortunately DPC Latency Checker only shows if there is a device driver problem, not which driver is causing the problem. You will have to manually disable and then re-enable each device driver from Device Manager.

Example When you use MS Security Essentials ( https://connect.microsoft.com/securityessentials ) together with uTorrent (1.8.3) the DPC latency increases dramatically after 3-4 hours of working. If you restart uTorrent or disable and then reenable the MSE Realtime Protection the DPC latency drops back to minimal level.


New Dell Vostro craptop
300µs-450µs basic load with optimized XP and all sorts of devices and services disabled, intermittent peaks of 4,000µs remaining, caused by normal Windows activities unless the configuration is crippled in a way that its no longer a laptop

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.

Download from
http://www.thesycon.de/deu/latency_check.shtml

1-shows in real-time how quickly your system reacts to the tasks it has to complete.
2-allows high-priority tasks to defer lower-priority tasks for later execution