that is what I do after asking for suggestions and trying it out on a different pc or laptophttps://www.thesycon.de/eng/latency_check.shtml
Easiest way to find what device / driver / software is causing the issue. Doesn't work well w/ Win 8 tho.
Unplug all devices, close all software. If you are getting spikes its probably a driver or hardware issue. Uninstall drivers until it stops. If you don't have spikes, plug in usb devices one by one. If still nothing then try software.
Usually the easiest, just recently I was confused as to why my X520-DA2 NIC wouldn't link up with the 10G SFP modules as the switch said the link was up but Windows wouldn't show it. Reinstalled Windows and everything just worked :doh:so annoying. I think I will just do a reinstallation of Windows.