The Setup

• Lenovo Thinkpad T420
• Intel Core i5-2520M CPU
• 16 GB RAM
• Intel 82579 Ethernet Interface
• Windows 10 Pro
• SDR Console v3.3 Beta Build 2870

The Problem

I had lots of audio stuttering/drop-outs while using [SDR Console] on my Thinkpad T420 (see above), even if no other programs were running.

The Fix

In order to find out if there are device driverrs that are blocking other processes due to high DPC latency spikes, I’ve downloaded and executed the tool LatencyMon.

The following screenshot shows the main screen of LatencyMon running:

The drivers with the highest execution times and/or numbers of DPC executions can be seen unter “Drivers”:

In my case it turned out that the ndis.sys driver was the main issue with extreme executions times (not visible in the screenshot, took it after the fix). After reading this very informative blog post I’ve replaced the generic network driver for Intel cards with a much older version from Lenovo (from 2011). The execution times are now still not great but much lower and I haven’t experienced any audio stutter problems in SDR Console anymore.

You can download the Lenovo driver from here: https://download.lenovo.com/ibmdl/pub/pc/pccbbs/mobiles/83rw15ww_64.exe