Many processes such as git and node are running 10x too slow on Windows 10, but run fast in safe mode

Question

Several command-line programs seem a little slow on a PC. How can I troubleshoot? For example, on this PC, It takes over a half-second to run git status:

PS> for (;;) { Measure-Command { git status } | findstr TotalSeconds  }
TotalSeconds      : 0.7119173
TotalSeconds      : 0.6040415
TotalSeconds      : 0.6117674
TotalSeconds      : 0.5779911
TotalSeconds      : 0.6069439
...

(On another PC, the above runs in 0.05 s.) A few other commands I've noticed take just a bit too long as well:

PS>  for (;;) { Measure-Command { node --version } | findstr TotalSeconds  }
TotalSeconds      : 0.4630501
TotalSeconds      : 0.3144418
TotalSeconds      : 0.2842615
TotalSeconds      : 0.2808537

(The other PC runs that in 0.02 s.)

One more for good measure:

PS> for (;;) { Measure-Command { npm --version } | findstr TotalSeconds  }
TotalSeconds      : 3.4839123
TotalSeconds      : 3.1501913
TotalSeconds      : 2.9817682
TotalSeconds      : 3.0423125

When these programs are running, I see CPU usage jump up, as if it is pegging 1/4th of the CPU's four cores. The CPU usage is elevated only in the process I invoked itself (i.e. Git.exe or Node.exe), not in any other process.

I have tried disabling as many Windows services as I can, to the point where my PC can barely do anything, yet I still get timings similar to the above. I have ensured that antivirus, firewall, and BeyondTrust are disabled, and the problem persists. I do not have ATI graphics (Intel HD 520 only).

The timings are the same whether I invoke from Powershell, cmd.exe, or bash.

The problem goes away in safe mode.

After booting normally, I've tried stopping all non-essential processes; the slowness persists. I've tried disabling all non-essential Windows services; the slowness persists. I've tried disabling all non-essential hardware in the Device Manager; the slowness persists.

Can anyone suggest a next troubleshooting step? I fear the cause of these issues is also slowing down other apps, as well.

Answer 1

In the end, it was indeed Symantec Endpoint Protection. Disabling the services doesn't seem to prevent the problem, but the following does. Run this to confirm it ends the problem.

"%ProgramFiles(x86)%\Symantec\Symantec Endpoint Protection\smc.exe" -stop

This, however, leaves me without Symantec Endpoint Protection.

There may be a way to whitelist certain programs with Symantec, but I'm not sure what it is.

EDIT: We subsequently found that the real delay came from Application and Device Control, not the bulk of SEP. This can be disabled in Settings > Client Management > General, at the bottom.

(Even deeper, there seems to be an experimental feature in only part of Application and Device Control that causes a delay on every process start. I am not sure what it is.)