lscpu shows the details about the CPU('s) . There are Core(s) per socket and Thread(s) per core. Cores are the hardware processors. Those cores can usually run 2 one threads.

cat /proc/cpuinfo returns everything about your CPU.

Checkout the flags line

cat /proc/cpuinfo

flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 mmx fxsr sse syscall mp mmxext 3dnowext 3dnow up ts

Cooling CPU's is vital. A maximum fill power temperature of 75°C seems to be a good value 85°C is acceptable 100°C is too much.

Gentoo Linux can make used of those things. Use ufed to turn on the corresponding use flags and have higher performance.

emerge --update --deep --newuse world

Check out gcc so it compiles with the right flags.