I am running Linux Mint 17 on my Laptop. Through the System Info GUI program, I found that the processor is Inter Core i3-2328M. When checking the System Monitor GUI program, it shows four CPUs numbered from 1 to 4. The specs say there are only two cores. What is the reason for the mismatch between the specs and the System Monitor?
Hyper-Threading Technology duplicates a limited set of CPU resources, such as registers, to enable each core to handle multiple threads. Modern CPUs have many different execution units in each core and not all of them may be in use by any particular program. When some of these resources are free, such as when one thread on a core is stalled, Hyper-Threading allows another thread to work on the same core.
A processor with HTT will appear to the operating system as having twice as many logical processors, but each pair of "cores" actually shares the same resources. This means that HTT is not a substitute for actual cores, although it will usually increase performance on workloads that use many threads, such as when multitasking.
Based on the specifications, your processor has two cores but can process four threads concurrently using Hyper-Threading Technology.
If you look under the Performance section on the Intel specs page you linked to, you'll see:
- # of Cores: 2
- # of Threads: 4
- Intel® Hyper-Threading Technology: Yes
Hyper threading on Intel Core i-x series allows the processor to run two threads simultaneously on a single processor core. Most operating systems will see this as four cores, as that's how it appears to the OS.
