[gstcharl]

When I view Task Manager I see 4 separate graphs for processors, thus I should have 4 processors although my Lenovo laptop lists an 'Intel Core i5 CPU M 520 @ 2.40 GHz' which is listed as 2 core.
On another laptop I view System Monitor (Linux base) and it lists 4 separate processors although it has 'Intel Core i5-2520M CPU @2.50GHz' which also is listed as 2 core.
Cores should equal processors and threads are not counted as processors in System Monitor (Linux) or Task Manager (Windows). What am I missing????

[LiveBrianD]

What you are actually seeing are threads. Normally, you have one thread per core. HOWEVER - if your processor has hyper-threading, you will see 2 threads for every core. This is what your laptop has - a dual-core processor with HT. Machines with multiple processors are very rare BTW.

[waldojim]

There are many different ways to report CPU's. It was determined years ago, that running multiple processors both increased power, and introduced new problems. As a response to the problems, and to help simplify the CPU design, multi-core CPU's were created. This eliminated most of the multi-processor bottlenecks, and allowed performance to scale rapidly. At the same time, the operating system see's a SINGLE CPU, with multiple working threads. Later this was expanded upon with HyperThreading (from Intel), which allows the CPU to be divided up in certain workloads so that it can execute more than one function at the same time on a single core. Essentially, making a quad core CPU look like an 8 core chip. Of course, these chips only work that way on limited workloads, and again, it needed to be reported to the OS so that the OS could control the load balancing.

The CPU's now are reported to the OS with a "package", "core", and "thread" count. Your i5 for example, has 1 package, 2 cores, and 4 threads. Windows 8 will now load balance against threads 1, and 3 first, then 2, and 4 in high performance modes, and is supposed to load balance 1 and 2 then 3 and 4 in battery saving modes. Upcoming Haswell chips from Intel will likely confuse this even further, as they are introducing even more shared execution resources.

The end result, is ignore what Windows Task Manager, or Linux is telling you. Use CPU-Z to see the details of your CPU.