# What bottlenecks WinRAR extraction speed?



## Ozpa (Jun 4, 2011)

Hello!

Quick question --> what does bottleneck WinRAR extraction speed?

I've noticed my CPU usage is around 5-10% during extraction. Is it the slow mechanical hard-drives?


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## scaminatrix (Jun 4, 2011)

Got two HDD's? Use one HDD as the "source" (the .rar you want to extract) and the other HDD as the "target" (the location you want the extracted files) and see if there is a difference. If there's no difference, your HDD isn't the bottleneck.


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## LAN_deRf_HA (Jun 4, 2011)

Just tried that, goes much faster when extracting to another drive.


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## Ozpa (Jun 4, 2011)

It's a little faster.

1GB.rar to the same 7200rpm drive --> 25s
1GB.rar to my Raptor --> 19s

So I guess it's the hard drive's write speed?


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## scaminatrix (Jun 4, 2011)

Or it could be the read speed of the source disk (if it's read speed is slower than the write speed of your Raptor). I unzip my content to a 4-drive RAID array, then watch/install/burn etc.


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## NdMk2o1o (Jun 4, 2011)

Ozpa said:


> It's a little faster.
> 
> 1GB.rar to the same 7200rpm drive --> 25s
> 1GB.rar to my Raptor --> 19s
> ...



Thats (if my calculations are correct) around 40MB/s to the 7200 drive vs 53MB/s to the Raptor

Is that unraring to the same drive or is that 1gb file on a seperate drive to the unrar drive?


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## Ozpa (Jun 4, 2011)

Oh sorry, should've been:

1GB.rar on 7200rpm drive, extracted to itself --> 25s
1GB.rar on 7200rpm drive, extracted to a Raptor --> 19s


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## NdMk2o1o (Jun 4, 2011)

Ozpa said:


> Oh sorry, should've been:
> 
> 1GB.rar on 7200rpm drive, extracted to itself --> 25s
> 1GB.rar on 7200rpm drive, extracted to a Raptor --> 19s



Ok then in that scenario the Raptor has an unfair advantage because the 7200rpm drive is hosting the file so there is no overhead from the Raptor having to read and write to itself at the same time, make sense? 

Can you transfer the file to the Raptor and then extract it to the 7200rpm to see if that makes a difference? 

Rule of thumb when unraring files is to unrar to a drive the file is not hosted on for best performance.

Really with compressed files the read/write speed of the drives does have an impact but that said there is other stuff going on with winrar cause I can unrar a file on my HDD which has 100-110MB/s read/write to an SSD so you would think you would get 100-110MB/s right? wrong, you wont ever utilise all of the available bandwidth. I have heard of other compression programs performing better than WinRar such as 7zip but I can't comment on whether or not they actually would make a difference as I have always used WinRar. 

I think even with 500MB/s throughput both ways you won't ever see near that speed or greater CPU utilisation just because of the processes what are going on which you don't see. But I could be wrong, hope that all makes sense btw am a little intoxicated lol


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## Ozpa (Jun 5, 2011)

Wow..

1GB.rar on Raptor, extracting to a 7200rpm drive took 7s :O


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## scaminatrix (Jun 5, 2011)

Ozpa said:


> Wow..
> 
> 1GB.rar on Raptor, extracting to a 7200rpm drive took 7s :O



That means the read speed on your Samsung is lower than the write speed of your Raptor. Your bottleneck is your Samsung drive. Considering it's your archive drive, great performance can't be expected from it. I'd recommend getting another HDD and using it as a "scratch" disk (only use it for converting/pagefile purposes).


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## Arrakis9 (Jun 5, 2011)

from OCZ summit to OCZ Vertex 2 takes 21 seconds
from OCZ Vertex 2 to OCZ summit takes 19 seconds 

file size is 1GB and 4 files contained in the archive, hope it helps


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## Anusha (Jun 5, 2011)

Ozpa said:


> Wow..
> 
> 1GB.rar on Raptor, extracting to a 7200rpm drive took 7s :O


this could possibly be due to data caching stuff in windows, more than drive speeds? 
if you want to rule that out, reboot and try again.


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## Completely Bonkers (Jun 5, 2011)

You've got enough memory to set up a RAMDRIVE.  Put your temp folder on the RAMDRIVE, and even stick your RAR file on the RAMDRIVE then upzip from there.

WHOOSH. Watch those new speeds.

http://www.techpowerup.com/forums/showthread.php?t=107670

BTW I think your original analysis is flawed by file fragmentation. Copying the RAR file to the RAPTOR actually did three things: i) moved to a faster drive, ii) effectively defragged or partly defragged the source, iii) avoid HDD head movement from source to destination if unzipping on same drive.  Try the RAMDRIVE for fun. How big are your unzipped files? Would they fit on the RAMDRIVE too?


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## RejZoR (Jun 5, 2011)

CPU and HDD is the limiting factor.


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