Can someone explain this test ?

Stiffex

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Oct 24, 2008
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OK i ran a small test on all my machines

My machine E8400, P45 board, 2GB OCZ Reaper 1150mhz
My daughters machine E2180, X975 board, 2GB Patriot 800mhz
Spare machine E6600, P35 board, 2GB Crucial Ballistix 1066mhz

I used a compressed file of 735mb and moved it from a flash drive onto the desktop of each machine and used WinRAR to extract the file.

On my E8400 pc it took 7 seconds to extract
On the E2180 pc it took 11 to 15 seconds to extract
On the E6600 pc it took 8 seconds to extract

The problem is: the longer the machines are on or after a reboot the speed of the extraction seems to degrade until the E8400 pc takes 35 seconds to extract and the other 2 machines are similar, however, if i delete the files and then drag the original 735mb compressed file back onto the desktop, the extraction speed goes back to 7 seconds, 11 secs, and 8 secs respectively. Extracting and deleting the file repeatedly results in gradual degrading of speed on all 3 machines, how can this be? Can anyone explain why this happens ?
 

Stiffex

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Oct 24, 2008
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The point is that this happens at all, i just want to know why it happens; how can the same file take 7 seconds to extract but minutes later take 30 seconds to extract on the same machine. I doubt very much that it has anything to do with drivers, it may have something to do with hard drive write speed or data packet distribution on the hard disc surface but thats why im asking, i want to understand why this happens and why it consistently happens on different PC`s with different hard where spec....

Surely someone must know why this happens ?
 

blackwidow_rsa

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Probably with the fact that the program must *ask* the OS to first delete the item, then continue to unzip. The more files, the longer it takes i guess. Small files are hell
 

4745454b

Titan
Moderator
The one constant is 2GBs of ram. A 735MB zip file is how much unzipped? When you run it the first time, the ram is emptied, and the contents are filled with the zip info. When you do other things, the zip file is put onto the swap file (if the zip program is left open) and other data is put into ram. If you go to extract it back, it needs to load info to and from the harddrives. This takes time, and is the cause for increasing extraction times. By deleting the info, it is removed from the swap file and ram, causing the original times to happen again. If you play around with the ram amount (not the timings.) you might be able to avoid the 35 second extraction.