CPU ID using C++ - windows

I want to get CPU Id of my computer (windows) using c++.

I used this code to get it.

It outputs information something like:

For InfoType 0
CPUInfo[0] = 0x5
CPUInfo[1] = 0x756e6547
CPUInfo[2] = 0x6c65746e
CPUInfo[3] = 0x49656e69

For InfoType 1
CPUInfo[0] = 0xf31
CPUInfo[1] = 0x20800
CPUInfo[2] = 0x41d
CPUInfo[3] = 0xbfebfbff

For InfoType 2
CPUInfo[0] = 0x605b5001
CPUInfo[1] = 0x0
CPUInfo[2] = 0x0
CPUInfo[3] = 0x7c7040

For InfoType 3
CPUInfo[0] = 0x0
CPUInfo[1] = 0x0
CPUInfo[2] = 0x0
CPUInfo[3] = 0x0

For InfoType 4
CPUInfo[0] = 0x0
CPUInfo[1] = 0x0
CPUInfo[2] = 0x0
CPUInfo[3] = 0x0

For InfoType 5
CPUInfo[0] = 0x40
CPUInfo[1] = 0x40
CPUInfo[2] = 0x0
CPUInfo[3] = 0x0

For InfoType 80000000
CPUInfo[0] = 0x80000008
CPUInfo[1] = 0x0
CPUInfo[2] = 0x0
CPUInfo[3] = 0x0

For InfoType 80000001
CPUInfo[0] = 0x0
CPUInfo[1] = 0x0
CPUInfo[2] = 0x0
CPUInfo[3] = 0x0

For InfoType 80000002
CPUInfo[0] = 0x20202020
CPUInfo[1] = 0x20202020
CPUInfo[2] = 0x20202020
CPUInfo[3] = 0x20202020

For InfoType 80000003
CPUInfo[0] = 0x47202020
CPUInfo[1] = 0x69756e65
CPUInfo[2] = 0x4920656e
CPUInfo[3] = 0x6c65746e

For InfoType 80000004
CPUInfo[0] = 0x20295228
CPUInfo[1] = 0x20555043
CPUInfo[2] = 0x30382e32
CPUInfo[3] = 0x7a4847

For InfoType 80000005
CPUInfo[0] = 0x0
CPUInfo[1] = 0x0
CPUInfo[2] = 0x0
CPUInfo[3] = 0x0

For InfoType 80000006
CPUInfo[0] = 0x0
CPUInfo[1] = 0x0
CPUInfo[2] = 0x4008040
CPUInfo[3] = 0x0

For InfoType 80000007
CPUInfo[0] = 0x0
CPUInfo[1] = 0x0
CPUInfo[2] = 0x0
CPUInfo[3] = 0x0

For InfoType 80000008
CPUInfo[0] = 0x2028
CPUInfo[1] = 0x0
CPUInfo[2] = 0x0
CPUInfo[3] = 0x0

I could not understand among those information which is my computer's unique CPU Id.

Can anyone kindly help me on this.

Do you mean "serial number", "who made the processor", or the "string that identifies the make and model of the processor".

Serial number:

Unless you have a Pentium III, you do not have a "unique ID" associated with your CPU.

Intel introduced the unique id (serial number) instruction with the P3. But after a huge uproar over privacy, they quickly disabled that feature in subsequent CPU releases.

For the record, the instruction that executed this feature in assembly:

mov eax, 3
cpuid

The processor serial number was the concatenation of eax, edx, and ecx together

You can achieve the same thing with __cpuid function by passing "3" as the second parameter. But it won't work or return a serial number unless you have a P3.

Vendor (who made the processor)

int regs[4] = {0};
char vendor[13];
__cpuid(regs, 0);              // mov eax,0; cpuid
memcpy(vendor, &regs[1], 4);   // copy EBX
memcpy(vendor+4, &regs[3], 4); // copy EDX
memcpy(vendor+8, &regs[2], 4); // copy ECX
vendor[12] = '\0';
print("My CPU is a %s\n", vendor);

In your case, this should print "GenuineIntel".

Make and Model (BRAND String)

If you want all the details of the CPUID instruction, including on how to get the make, model, and stepping of your CPU, as well as the "Brand String" such as "Intel(R) Core (TM)i7-3770 CPU @ 3.4GHZ...." you can reference the Intel manual at the link below. Scroll down the document to find the docs for CPUID. I'm too lazy to type it up for you.

http://www.intel.com/content/dam/www/public/us/en/documents/manuals/64-ia-32-architectures-software-developer-vol-2a-manual.pdf

The __cpuid() instruction provided by the MSVC compiler maps "InfoType" to EAX before the call to the cpuid instruction. After that instruction returns, EAX, EBX, ECX, and EDX get copied to the CPUInfo[4] array you passed into this function.