Too slow archlinux

Question

I have both ubuntu (latest - 15.04 with fresh updates) and archlinux (latest) but when I boot in arch I have a problem: everything is slow as a snail.

On archlinux the flashplugin FREEZES the whole system - even cursor does not move when something is playing from both chromium and firefox browsers. I've enabled hardware acceleration in /etc/adobe/mms.cfg, my nvidia proprietary driver (352 version) works amazingly good in meaning of acceleration and opengl stuff. But this is not the only problem - when I try to compile something on archlinux, with make or make -j9 (fits my configuration fully) it does it extremely slow a little-little project compiles like 15 minutes.

On ubuntu I have no any issues with flash plugin everywhere. Also, exactly this project that compiles ages on archlinux I compile on ubuntu less than one minute. This problem is not only happens to compile or flash player but even responsiveness in the UI: on ubuntu it is working pretty good everywhere but on archlinux I have awesome-wm installed only without even any login managers - it freezes sometimes too. I don't even know where too look the problem.

My PC:

Intel Core i7 2600 (always turbo-boosted)
DDR3 16GB RAM
NVIDIA 550GTX

Compilers (both are slow, but clang is 1-2 minute slower than g++):

g++ (GCC) 5.1.0
clang version 3.6.1 (tags/RELEASE_361/final)

Answer 1

Not sure why, but the problem is gone. What I did since posting this question is:

1. fixed cpu - changed thermal compound, cleaned the whole pc. I did this because I found that my processor is very hot. I also noticed, when it is hot - it is much slower.
2. updated the distro every day. So this may be a fix in the kernel or something.. Now everything is even better than in ubuntu.