I upgraded my PC from an AMD A4 6300 dual core 3.7 GHz (16 Gb RAM) to an AMD FX8350 octa core 4.0 GHz (32 GB RAM). I was expecting a (8-2 cores) / 2 cores = 3-fold increase in performances and I tested it by extracting a tar archive that produces a 52 Gb file. With the A4 processor it has taken 561 seconds to extract the file, with the FX processor it has taken 454 s. Thus the fold increase of performance for this task has been: (561 s – 454 s) / 561 s = 0.19, which is a bit small. So maybe what I have to look at is (4.0-3.7 GHz) / 3.7 GHz = 0.08 fold increase.
My questions are:
1. how do I assess the true computational power of a machine? If on the paper I have a given number of processors and a certain speed level, is there a standard measure that allows me to compare two machines for real (what I obtained with the reported process suggest me that I could have kept my previous machine and save the money since the increased performances are minimal)
2. what is the impact of the motherboard on the processor performances? I understand that also the motherboard is involved in the final performance of the machine, so that the final speed of the processor (let's say 4 GHz) is just nominal: the motherboard might hamper the speed and reduce the performances. So what shall I look in the motherboard specification in roder to achieve higher computational power?