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