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.
The bogomips line tells something about its performance measured and required during kernel boot. The MIPs (million instructions per second) value is therefore bogo.
cat /proc/cpuinfo | grep bogo
bogomips : 3979.99
For performance measurements programs as sysbench are more suitable: sysbench --test=cpu run
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.