[SOLVED] 4 Core CPU but PC is only using 2 of them?

[Sean17]

I have AMD PRO A8-8650B R7, 10 Compute Cores 4C+6G Processor, In CPU-Z it shows I have 4 Cores 4 Threads but in task manager, it shows 2 Cores 4 Threads, What should I do to use all my cores?

 

[cdrkf]

I have AMD PRO A8-8650B R7, 10 Compute Cores 4C+6G Processor, In CPU-Z it shows I have 4 Cores 4 Threads but in task manager, it shows 2 Cores 4 Threads, What should I do to use all my cores?

Your machine has 4 threads - that is correct, the only difference is the way Windows vs CPU-Z report them. It's down to how AMD built that architecture (it's a derivative of the Bulldozer series of cores - where AMD created dual core 'compute modules' with two integer clusters, one floating point unit and a shared front / back end). The A series APU's only have two modules, which AMD calls '4 cores' but Windows treats as 2 cores with hyperthreading (i.e. 2 cores 4 threads) - this was done to get maximum performance out of the APU, as when one 'core' in a module is being used, the second has to wait due to some of the resources being shared so for Windows it's faster to send a new intensive task to a core on the second module first, before using the shared cores.

This was also why the AMD FX '8 Core' cpu's could only keep up with Intel 4 core parts of the time- AMD got a bit creative with the definition of cores to make the cpu's sound more powerful than they were (which actually made them look worse imo) - they ultimately lost a class action lawsuit for calling the FX series 8 core cpu's as they functioned more like a quad core.

A side note - you can see the 4 threads usage individually by right clicking on the usage graph in task manager and going to 'change graph to -> logical processors' and you will see 4 individual graphs (one for each core).