Sorry to disappoint Amazon readers and reviewers but this Intel i3-2100 processor is only dual (2) core and not as advertised quad (4) core processor. It does have quad (4) hyperthreads but only two physical cores. Hyperthreads are very different to multi-cores when describing central processing units (CPU's) and there are big differences in the cost between 2, 4, 6 and multi-core processors.
I contacted Intel after I realised there was something wrong in this description of this and another CPU, it turns out that Intel describe the i3 processors as dual (2) core and not as described in the titles on the Amazon website as a quad (4) core processor. Quad (4) core processors are limited to the Intel i5 processor range, the Intel i3 range of processors contain dual (2) core and quad (4)hyper threads, where as the Intel i5 processor range is Quad (4) core with 8 hyper threads and Intel i7 is 6 or 8 core which are multi threaded processors.
I agree the price and processing power of this Intel i3-2100 processor and that of the i3-2120 are good for the price you pay, but the description of these processors claiming they are quad (4) core is factually wrong and very misleading their buyers into a false sense of purchasing processing power which is a misrepresentation under the sale of goods act which Trading Standards are now investigating.
source: Intel description of the Intel i3- processor, online 25/04/2012, [...]