1000HZ kernel and decreasing it

[blindek]

Hello,

Now I have patched my kernel over these guide http://wiki.fragaholics.de/index.php/EN:Linux_Kernel_Optimization . Now as on guide my kernel is running on 1000HZ and I think that it is consuming a bit to much resources and my CPU. Do you think these could be possible, that because of 1000HZ system charges more CPU than normal?

I don't need 1000FPS boosted CS servers, 500FPS will be enough and because of that I was thinking to decrease HZ of kernel.

Do you think these will decrease a bit of CPU usage?

For running 500FPS server a 500HZ kernel will be enough?

Thanks for your help.

[BehaartesEtwas]

As stated in the "Playing around" section, you probably don't need HZ=1000 even for 1000 fps. I would recommend trying to set HZ=100 and enabling dynamic ticks ("tickless system"). hrtimers should still make your server running at 500/1000 fps, but you have less timer interrups and less system load.

btw: the difference in the load between 500 and 1000 fps is very small. the total amount of work is the same (unless reducing the tickrate), it's only a question when some of the work is done. of course higher fps will increase overhead, but thats not really a big difference. (but also the difference for the gameplay is minimal)

[blindek]

Huh, do you think it will be good decreasing HZ even to 100HZ? Even lower then default on debian witch is 250? It will not make anyithing worse in the server performance having 100HZ kernel? Because I am also running call of duty servers. Will these 100HZ affect COD servers you think?

So you think I leave all kernel settings as wrote in the howto http://wiki.fragaholics.de/index.php/EN:Linux_Kernel_Optimization only don't disable tickless system but enabling it and changing HZ to 100?

[BehaartesEtwas]

try it out. i never ran any cod server, so i don't know the effects... but in principle, the HZ are a legacy construct. modern software shouldn't relay on them...

[afterhoursgaming]

it works fine with COD4 servers at any hz I have a couple that work great even with default kernel.

[blindek]

Yes I know. I had default kernel for while and is good on 250HZ. But he propose me to run on 100HZ witch is 150HZ lower, also fine?

But I am quite skeptic and for first i will try only to decrease for running 333FPS server. To do it it is enough to run 333HZ kernel?

[BehaartesEtwas]

for recent kernels, the HZ and the fps arn't correlated anymore (at least if hrtimers are enabled). switching from one HZ to another is very easy, so just play around with it. I would recommend starting with HZ=100 (and tickless system) and only change to higher HZ if problems occur. You cannot destroy anything, worst case is an unusable game server until you recompiled with a higher HZ...

[Clauu]

(03-08-2009, 07:11 PM)BehaartesEtwas Wrote:  for recent kernels, the HZ and the fps arn't correlated anymore (at least if hrtimers are enabled). switching from one HZ to another is very easy, so just play around with it. I would recommend starting with HZ=100 (and tickless system) and only change to higher HZ if problems occur. You cannot destroy anything, worst case is an unusable game server until you recompiled with a higher HZ...

How to change hz / hrtimers / tickless system without compiling a new kernel because I have a little problem:

I use hlds linux on a ubuntu machine, and my problem is unstable fps ... If I set sys_ticrate to 333 witch is perfect for a smooth gameplay after a while(about 10 minutes) sys_ticrate is autochanging to 500 ... why ?

Server OS: Ubuntu 9.10 Server Edition 32bit
Processor: Intel Core2Duo E6400 @ 2.13 GHz
Ram: 2GB
Game: Hlds - CounterStrike
Start Up Command: ./hlds_run -console -heapsize 1048576 +servercfgfile server.cfg -zone 2048 +sys_ticrate 333 -game cstrike -restart +secure +sport 27014 +log on -autoupdate
Admin Mods: Metamod+AmxModX

[BehaartesEtwas]

(02-16-2010, 04:53 AM)Clauu Wrote:  How to change hz / hrtimers / tickless system without compiling a new kernel

not possible. you have to recompile the kernel.

Quote:I use hlds linux on a ubuntu machine, and my problem is unstable fps ... If I set sys_ticrate to 333 witch is perfect for a smooth gameplay after a while(about 10 minutes) sys_ticrate is autochanging to 500 ... why ?

maybe some plugin?

[Clauu]

Yes, you where right, a nasty plugin whas doing that, my bad.