Memory Bandwidth Performance
The AMD A8-3850's memory bandwidth performance is comparable to the Athlon II X4 640. Although the Athlon II X4 640 did produce 15% more bandwidth, it was using higher spec DDR3-1600 memory opposed to the A8-3850's DDR3-1333 memory.
However, when increasing the DDR3 memory frequency to 1866MHz on the A8-3850 platform the memory throughput improved significantly. Read bandwidth increased by 23% while write bandwidth saw a massive 55% improvement.
The AMD A8-3850 might have twice as much L2 cache as the Athlon II X4 640, but it's no faster. In fact, it was the slowest processor tested when running the AIDA64 L2 Cache performance test -- regardless of RAM speeds.