I agree with @spikeyxxx , It is more a Blender problem. But I am sure the way things are going at Blender HQ it will get better.
On your CPU you have 8 cores but the task you are executing in Blender will use 1 core, only 12.5% of the CPU.
The 16 CPU’s you refer to are actually the logical cores. Logical cores are the number of threads that can run on each core through the use of hyperthreading. So for your 8 core CPU must be 2 threads per core giving 16 logical cores.
I think you will find only 2 logical cores will be in use by the Blender task at a time, it may use 4 but alternate 2 at a time or switch to another core as one process ends and another starts.
For greater performance on this type of task a good CPU speed is best over number of cores. More cores is better when rendering. Your CPU runs at 2.40Ghz which is not great unfortunately. My CPU runs at 3.5Ghz and I rarely have an issue like this, however I only have 4 cores so I am slower when rendering.
Overclocking the CPU is an option but not one I would recommend. Other factors will come into play such as cooling of the CPU. You could cause damage to the CPU.
My advice would be grin and bear it, and save often, close and reopen Blender or restart your computer will clear the memory and keep you chugging a bit longer, like putting another shovel of coal on the fire, but there is always a top speed.
