CPU consumption
June 6, 2006 - 18:40
CPU consumption
Hi,
I'm just wondering about shm_and_disk value
By using shared memory to store the cache, is it use a lot of CPU other than store the cache on disk only?
If I'm concern about the CPU, what should I use?
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technoratiJune 16, 2006 - 14:22
Hi,
In general I/O to the disk are the slowest thing on a server.
Anything that uses more ram then the hard disk will be "softer" on your CPU.
If you got the ram try all in RAM: shm_only or if your ram fills up try shm and finally shm_and_disk.
As a rule you have to reduce the time, the current number of computations take to perform, to reduce the load on the CPU. So anything that will make these computations fasters will enable then to be "in and out" of the CPU faster and reduce your load.
So if you got the RAM, use more of it. This is true for all application layers involved (System caches, WWW Server caches, eAccelerator cache, database caches....). For example, if you use IIS, tweak it to use more ram for your "high traffic" files (logs ? etc...), reduce the time it take to process DB requests...etc...
Also high CPU is not realy a problem if you site is still fast. An average of 10% CPU usage is practicaly no different then 0%.
If your CPU average is 20%+ and growing you need serious optimization and/or hardware upgrades.
June 30, 2006 - 06:31
As i installed a ram disk to start over php from ram directly , i noticed also more cpu consumption because the ramdisk driver needs resourced to be handled by cpu.
June 30, 2006 - 07:54
Hi petesky,
Welcome to the board.
Do you seem much speed improvement ?
I would not think so since the PHP DLL should already be loaded in keep in memory by the OS. I know IIS will do this when you select the approriate option in the IIS-entry mapping the extension to the DLL. I suspect both Apache and Samba have some form of DLL caching mechanism.
You might get the speed improvement without the over-head by simply storing the PHP tmp folders in the ram disk.
Cheers,
Chris
PS: I don't do a lot of IM yet (maybe once of twice a quarter for some business stuff).
June 30, 2006 - 08:51
Hi chris !
I use www.sambar.com on W2K and i see no improvement.
That's may because i have a lot of fine tuning done on my server (registry based and file system based).
But i always look for better performance because i'm a performance junkie :-)
PS: Thx for welcome message - i do a lot IM's because i often need instant help.
Joined: 2006-05-23