Almost three weeks ago, I had to buy a new laptop for my personal use. The reason was I gifted my old Dell Inspiron and my Acer 8920G was busted. The only system which I was left with, for my personal use, was my HP desktop, though I have one old Acer Aspire. Well, I needed a latest laptop which could be used for next four years: a laptop with multi core processors, big hard disk, plenty of RAM and many other things. I have had budget of €1000. Well, I just did not go and buy the laptop but I waited for deals and I found one during Christmas era. I bought Toshiba Satellite 15.6″ L750-1T9 Laptop. It has Intel Core-i7 2670QM, 6GB RAM, 640GB HD and many other features. It cost me around €600. I will review it some other time.
Before proceedings, you should know that any processor in the world will have at least one core. Unless it is stated otherwise, a CPU is always considered single core processor. The name scheme reveals the number of cores in a processor, like AMD Athlon II X2 shows dual core processor, Intel Core i7 2670QM is quad core processor (i7 is always quad core) and so the other processors can be know. And you should know that I am zero when talking about hardware. I know nothing about hardware.
Few days back, I was checking RAM and CPU consumption in Toshiba Satellite 15.6″ L750-1T9 Laptop and I noticed that CPU Usage History is showing 8 windows under Performance tab. I knew that Intel Core-i7 2670QM has four cores and 64bit processor. Why it is showing me the history of 8 processors? It should only show a maximum of 4 cores. Well, I questioned myself and started searching Internet for the answer. What I found was really interesting but more complicated. I will tell most of what I found and will also tell about what is the real way to find real number of cores in your CPU and how many threads can be supported simultaneously.
The easiest way to find out how many cores your CPU has is to go Task Manager and then Performance. There CPU Usage History shows the number of Cores, the CPU has. If you see only one CPU History graph, go to main menu View->CPU History. In CPU History, you will see One Graph, All CPUs and One Graph Per CPU. If you do not see option One Graph Per CPU, this means your CPU is single core. OK, This looks procedure looks quite legitimate and tells truth about CPU cores. But for Intel Core i-7 2670QM, it is not right way to find total number of cores. Do not believe me, look at the below photo and you will know.
I opened Resource Monitor simply from Task Manager->Performance and at the bottom, you will see a button named Resource Monitor. There it was also showing eight CPUs ranged CPU-0 to CPU-7.
I thought to check it from DirectX Diagnostic Tool. Through Run, use dxdiag and window like below opened. Checking this window also shows 8 CPUs.
Did I forget to mention that My Computer Properties did not show any number of CPUs or Cores?
It is a lot more confusing now. Intel Core i7 2670QM has only four cores but all above methods to find the real number of cores showed 8 CPUs. Things are becoming more complicated.
I googled the problem and found a tiny free software named CPUID CPU-Z (v1.59). Using this CPU-Z revealed the real number of cores and also revealed the truth behind showing 8 CPUs. If you look at the photo below from CPU-Z, you will see that it is clearly showing that Intel Core i7 2670QM is a 4 core 64bit processor and it supports 8 threads simultaneously. Intel’s info page also showing it Quad-Core supporting 8 threads.
OK, CPUID CPU-Z has made it clear that Intel Core i7 2670QM is quad core processor and also supports 8 threads simultaneously. In reality, one core or single core CPU can only support one thread at a time. But Intel’s new Hyper Threading technology has made it possible to support more than one thread by single core or single processor. Intel Core i7 processors supports Hyper Threading and one core can run two thread simultaneously. This means 4 cores can run 8 threads. So, does it mean Task Manager, Resource Monitor and DirectX Diagnostic Tool, all were showing 8 threading capability as 8 CPUs? I think so. If you like, you may correct me if I am wrong.