[koyote]

Hi guys,

I'm struggling with an issue i couldnt find any answers by searching google.

Basically I have benchmarked two different php scripts, one that uses classes and page templating, meaning that the page to be displayed is first created from code and a template, then cached and then displayed to the user. While pretty fast, and very fast if its already cached, it takes aproximately 400kb of memory (im using the memory_get_usage function to find out how much memory is used)

The other script only uses functions and no templating at all, and has php code embedded in the html. This one, while slower in execution (time wise), takes a maximum of 150kb of memory on a run.

Note that on the script that uses classes, most of the classes are extended from parent classes.

Now my question is how important is memory usage here, i mean does php use ram or virtual memory, and how much memory is acceptable to be used for a server not to get stuck so to say.

While 400kb might not seem much, im thinking that if there are 100 users on the server at the same time, will the memory usage be 40mb?

Thanks in advance guys

[odi]

If you have 100 users there is not the simple calculation 400kb * 100, as you say there is a cache and if the code of a function is already in the memory there is no need to load it again.

I don't think this is a big issue unless you're using really memory-eating scripts that make connection to other servers, calculating pi or thing like that

[koyote]

Thanks for the reply mate.

What confuses me with the memory_get_usage function is that it still displays 400kb of memory is used when i run an already cached page.

So the first time i run the page, i get: time of load: 0.15 seconds, memory usage: 400kb

The second time i run it, i get: 0.002 seconds time of load, memory usage: 400kb.

So basically thats why i get confused with this template caching thing.

Also if i have about 3-500 constants defined that need to be loaded every time, i see about 100kb being used by them, do arrays occupy less memory, and also are arrays faster than constants execution wise?

Cheers

[UnrealEd]

maybe this will disappoint you, but it's true: when you're execute some code and it uses an array of length n, it will take time n (for instance). now when you use an array of size 2n, most of the time the duration wont be 2n, but an exponential of n (n², or more).

I'ld say: test your code. if you want to see if it will take about 40Mb when 100 users are executing your script, then simply open 100 browsers (this might be a lot of work, but with a javascript it should work). then simply see what the memory_usage is

UnrealEd