Sometimes, you need to get information about the CPU on a machine, whether it's because you just can't remember what kind of CPU your computer has or you need a specific detail, such as the number of cores or whether it's 32- or 64-bit. Here are six ways to get that information on Linux.
[ Explore the central processing unit's components and functionality. ]
GNOME settings
If you use the GNOME desktop, you can see what kind of CPU you use in the Settings application.
First, click the Activities button in the top-left corner of the GNOME desktop and type Settings. In the Settings window that appears, click About in the left column.
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KDE Kinfocenter
If you use the KDE desktop, find all the CPU information you could ever need in the KInfocenter application.
First, click the K Menu in the bottom-left corner of the KDE Plasma Desktop, and select Info Center. In the Info Center window, click Devices in the left column and then CPU.
[ Keep your most commonly used commands handy with the Linux commands cheat sheet. ]
Look at /proc/cpuinfo
While we often use the term "Linux" (or sometimes GNU+Linux) to refer to the operating system, it's a kernel first and foremost. As the binary responsible for bootstrapping your system, Linux has information about everything it's managing, including the CPU. This data is stored in the /proc virtual filesystem in a file named cpuinfo. It's this file that applications like KInfocenter parse to deliver data about your CPU, but you can parse it yourself, too.
$ cat /proc/cpuinfo | less
processor : 0
vendor_id : AuthenticAMD
cpu family : 25
model : 33
model name : AMD Ryzen 5 5600X 6-Core Processor
stepping : 0
microcode : 0xa201009
cpu MHz : 2200.000
cache size : 512 KB
physical id : 0
siblings : 12
core id : 0
cpu cores : 6
[...]
Try arch
If all you need to know is the architecture of your CPU, you can use the arch command:
$ arch
x86_64
[ Keep your most frequently used commands handy with the Linux commands cheat sheet. ]
Use uname
The uname command is usually used to print information about your kernel. Because your kernel is highly dependent on your CPU, you can extract a lot of CPU data from its output. For example, you can get the vendor of your CPU with the --hardware-platform (-i for short) option:
$ uname --hardware-platform
authenticAMD
You can also get the model of your CPU with the --processor (-p for short) option:
$ uname --processor
AMD Ryzen 5 5600X 6-Core Processor
And finally, the architecture with --machine (-m):
$ uname --machine
x86_64
Programming libraries
Sometimes you need CPU information within a non-interactive interface. On Linux, any command you type into an interactive terminal session can be scripted so that it's non-interactive, but sometimes you're working with more than just a simple script. There are usually libraries for obtaining that information if you're using a compiled programming language and you need to determine what architecture you're on. However, you may also be able to do some rudimentary tests to determine the architecture without importing a special library.
There are too many programming languages for me to give an example of all of them, but here's a simple example in C++ of the kind of logic you might use:
#include <iostream>
using namespace std;
int main() {
if ( SIZE_MAX == 0xFFFFFFFF ) {
cout << "32 bit";
} else if ( SIZE_MAX == 0xFFFFFFFFFFFFFFFF ) {
cout << "64 bit";
} else {
cout << "Unknown";
}
return 0;
}
This code checks SIZE_MAX to determine the potential maximum size of a variable. If it's set to 64-bit, then the CPU that compiled the code is capable of 64-bit.
That's not the only way to extract that kind of data; if you have libraries that make it even easier, you can use those.
Knowledge is power
Getting insight into what CPU you're running is a useful trick to know. It may not come up often, but it's annoying when it occurs and you're caught without the necessary information.
I've covered all the ways I could think of to get CPU information in this article, but there are many other ways I haven't thought of. How do you get CPU information on your systems? Email us at enable-sysadmin@redhat.com to let us know.
