The AMD A8 4555M is based on Piledriver architecture that has 4 cores and handles 4 threads simultaneously. TDP is 19 watts which makes it perfect for use in slim laptops.
A8 4555M features include SSE (1, 2, 3, 3S, 4.1, 4.2, 4A), x86-64, AES, AVX, FMA and full 64 bit support. It runs at 1.6GHz under normal mode and 2.4GHz under turbo mode.
The AMD A8 4555M scored 2808 in the passmark benchmark test.