CPU speed on compression/encryption

[Jerboy]

how much role does CPU speed play on archiving and encrypting speed? When I compress data with WinRAR in RAR mode on Athlon 1400, it still takes significant time and not that much faster than my P3 600.

 

[cookieman]

In archiving/encryption the CPU's speed is the most important factor. It's weird that you have that Athlon so slow.....
To my knowledge when you encrypt/archive some stuff the ALU of the CPU (not the FPU) part is what is most used. I've never seen
FPU used for that.
It's possible to speed up the algorithms used with MMX/SSE/SSE2/3DNow but that version would run better on some CPU's and would be slow on others. I don't know about WinRar...

What files are you trying to compress? (Size does matther). If you have manny small files (10.000 or more of 32Kb or less) then the
compression speed would be very limited by the HDD speed. You could hardly see any difference because the program it drives the HDD like mad (open file/read file/close file/ read next FAT entry/...) and the UDMA can be best exploited when the OS reads lineary from HDD (big files...). Also use OS that caches the disk well (not DOS) to see any difference...

To compare that Athlon to the P3 I suggest you take a really big file (650 Mb or so) and fed it to WinRan on both machines. Or use Lame to compress a big Wav. That Athlon must at least be twice as fast as your P3 if you have a fast HDD.

I can see about a linear speed increase with the CPU speed increased (I used to compress big AVI's).

There is nothing to be done if you want to compress many small files. Get faster HDD's with bigger cache...

Test it. I'm interested in what you find out ...

Cheers,

 

[Rand]

Depending upon what your compressing memory bandwidth can also have a large impact upon the time it takes.