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here is my situation:

I have a bash script that runs a zcat command, which uncompresses an image. For some reason, it runs very slowly even though it's only a 2 gb file. This computer has a high-end processor (i7-3610Q@2.3Ghz) so it shouldn't be a bottleneck, especially since another older computer with subpar hardware runs the exact same script very quickly. The same thing happens with a dd command, running in the same script.

This computer runs an almost freshly installed Ubuntu 12.04, up to date. Running the system monitor during the two commands reveals that the first CPU is widely used by the process, while the 7 others much less. Especially the last 4 cores. Graph looks like a rollecoaster. My guess is that it is not

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I'm afraid it's quite normal for g(un)zip to not utilize multiple CPUs in parallel. If that's what you were asking. But do show the actual script / commands just in case. For example you mention dd, which needs bs=1M or similar since the default block size (512 byte) is just way too small for performance. –  frostschutz May 31 '13 at 21:08
Thanks for your answer. Here are the two problematic commands: # Uncompress the image zcat -v $SHRUNK_TEMPLATE > $TEMPLATE # Make a fresh copy dd -v if=$TEMPLATE of=$IMAGE I am not aware of the bs=1M, I will look into it, thanks. –  user163401 Jun 3 '13 at 13:44
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