High CPU usage for running Tremulous

[kongkin90]

After i reinstall my XP, CPU usage always stay at 8x%-9X% for running Tremulous. Even at muen screen.
What problems am i facing

Sorry for my poor English

[F50]

Quake 3 based games are cpu bound, so yes, expect to be using all of one core.

[Cadynum]

For some reason, at least on my setup, in gpp cpu usage will go from ~25% to ~100% when I set com_maxfps above 100.
I have no idea why actually, just tested it right now (in the menus).

Edit: I did some more testing on UTCS:

FPS - CPU utilization (for one core)
60: 11%
70: 12%
80: 17%
90: 45%
91: 98%
333: 97%

The fps is stable all the time.

[F50]

woah, interesting.

[kongkin90]

For some reason, at least on my setup, in gpp cpu usage will go from ~25% to ~100% when I set com_maxfps above 100.
I have no idea why actually, just tested it right now (in the menus).

Edit: I did some more testing on UTCS:

FPS - CPU utilization (for one core)
60: 11%
70: 12%
80: 17%
90: 45%
91: 98%
333: 97%

The fps is stable all the time.

Wow, that is true on me. thx a lot

[Kiwi]

90: 45%
91: 98%
333: 97%

That's odd...

[kevlarman]

not really, the fps limiter doesn't trust the operating system to accurately sleep less than 10ms, so it busy-waits instead. there are probably some circumstances where that threshold can be a lot lower, but the problems with setting it too low are worse than those with setting it too high.

[gimhael]

That depends on the client, Tremfusion doesn't do that busy waiting even for small wait times.

Also the time to wait in milliseconds is computed by integer division which rounds down, so 90 fps -> wait 1000 / 90 = 11.111111 -> 11 ms, while 91 fps -> wait 1000 / 91 = 10.98... -> 10 ms. So anything more than 90 fps means the default client tries to grab 100% CPU.