On Thu, May 21, 2020 at 09:26:59AM -0400, cpham2...@comcast.net wrote: > Hi, I am running linuxptp version 2.0 in software timestamp mode, and I found > the "master offsets" are all over the places. In ~7000 offset measurements, > more than 50% is greater than 100 micro-sec. Maximum offsets observed is > around 300 micro-secs. I wonder anyone ran linuxptp in software timestamp > mode and what accuracy level was observed. > My master clock and PTP clients on are a local network with no PTP-support > switches. There are 4 switches along the path between the master clock and > the clients. When I ran linuxptp in hardware timestamp mode in the same > network setting, I achieved great results: 90% of master offsets is within 1 > micro-sec. In software timestamp mode the master offsets are higher than > expected. Is there anything I can do to improve the accuracy?
There are few things you could try to improve the stability with SW timestamping: - disable interrupt coalescing on the NIC with ethtool -C if possible - disable power saving features (e.g. set the CPU to a constant frequency, disable idle states) - disable energy efficient ethernet (EEE) - this helps with HW timestamping too To improve accuracy, use the same HW, SW, and configuration on the master and slave, so the errors in RX/TX timestamping cancel out. -- Miroslav Lichvar _______________________________________________ Linuxptp-users mailing list Linuxptp-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-users
