Jepio's blog

Finally a new laptop

The time of my old laptop has come, it has finally died on me under mysterious circumstances¹. It was a Samsung R530, with a T4400 2.2 GHz dual core processor. Since I use gentoo most of the time I have to compile (almost) all of my packages from source, which is very demanding on the processor. I did not know unsuitable my old laptop was for this task until this weeks.

I have now purchased a Thinkpad T440s, with i5-4210U with a 1.7 GHz dual core processor. But this time, it comes with turbo boost up to 2.7 GHz - though I mostly see about 2.4 GHz on the clock - and hyperthreading. I have known about hyperthreading for a while and because I know how it works (time slicing) I didn't think it was particularly exciting. I couldn't have been more wrong. It turns out that compiling is a sufficiently I/O heavy operation, that it can make reasonable usage of the hyperthreading capabilities in the processor and get a close to 2x boost compared to the 2 physical cores. Here's a couple of packages whose compile times can be compared:

package	time samsung	time thinkpad
llvm-3.6	1 hour	37 minutes
gcc-4.9.2	1 hour 40 min.	36 min.
boost-1.56	57 min.	10 min.

Now, I must admit that the comparison for boost is probably not fair - in one case I built the static as well as the dynamic lib versions, and in the other only the dynamic libs. But the speedup is amazing nonetheless.

It also seems that the Thinkpad has much better Linux support in general. I tested Fedora 22 and everything ACPI related worked out of the box. On Gentoo everything works - except for the microphone. The mic mute LED turns on at udev device enumeration during init and stays on, I can't get it to work. Anyone else experienced this? If so write me because I still haven't found a solution.

Not really... but let's not get into the details. ↩

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