My system:
Memory - 3.9 GiB
Processor - Intel® Core™2 Duo CPU T6600 @ 2.20GHz × 2
Graphics - ATI Moblitiy Radeon HD 4650 Gallium 0.4 on AMD RV730 (DRM 2.39.0, LLVM 3.5.0)
2xMonitors setup(1920x1080 & 1600x900)
Base syste - Debian GNU/Linux 8 (jessie) 64-bit
GNOME 3.14.1

HI, I just checked the console log after my game started a little slow and saw the following.

2 CPUs, Frequency: 1.2 Ghz,  Features: GenuineIntel SSE SSE2 SSE4.1 MMX RDTSC CMOV FCMOV
I've restarted the game and it displayed 2.2 Ghz corretly, after an other restart it showed 1.2 Ghz again. Whats happening there does Dota2 runs with reduced resources sometimes? If so how do I change it.