The Ubuntu family update, the most commonly used:
Flavor |
Ubuntu |
Budgie |
Linux Mint |
Kubuntu |
Ubuntu Mate |
Xubuntu |
Lubuntu |
Architecture |
Armhf, ARM64, PowerPC, i386, x86_64, server only: PPC64el, S390x |
i386, x86_64 |
i386, x86_64 |
i386, x86_64 |
Armhf, powerPC, i386, x86_64 |
i386, x86_64 |
Armhf, powerPC, PPC64el, i386, x86_64 |
Desktop |
Unity |
Budgie |
Cinnamon, Mate, Xfce |
KDE |
Mate |
Xfce |
LXDE |
CPU Req |
2 GHz dual core CPU (better recommended) |
1.5 GHz i386 or x86_64 (better recommended) |
2 GHz i386 or x86_64 (better recommended) |
2 GHz i386 or x86_64 (better recommended) |
Pentium 4 or Pentium M or AMD K8 (Core 2 Duo 1.6 GHz or better recommended) |
PAE capable Pentium 4 or Pentium M or AMD K8 (better recommended) |
Pentium 4 or Pentium M or AMD K8 (better recommended) |
RAM Req |
2 GB (more recommended) |
2 GB (more recommended) |
1 GB (more recommended) |
2 GB (more recommended) |
2 GB (more recommended) |
1 GB (more recommended) |
1 GB (more recommended) |
Disk space |
25 GB or more |
to 60 GB |
15-20 GB |
to 25 GB |
9-16 GB |
7.5 GB or more |
4.6 GB or more |
Updated for 18.04 LTS versions! Note the change in minimum required CPU: no longer will a Pentium II (Lubuntu) or PIII or AMD K7 (Xubuntu) do, it seems...
These minimum requirement figures given take into account the install of a 32-bit version, the support for which will be dropped soon in most distro's (with the 18.10 release actually). 64-bit versions may have higher requirements. When you do have such a 64-bit system, you have the advantage of a better CPU than these minimum requirements and almost no limitation in the amount of RAM -the more the better- you can place, other than the limits of your mobo -which may be different from those advertised. I have 16 GB running in a J5005 system that officially supports only 8 GB and know of people who have 32 GB in the same motherboard.
Most x86 systems (read x86-64 systems) nowadays can take at least 8 GB of RAM and a speed of 1.5 GHz for a CPU, APU or SOC seems the bare minimum now.
As an example: My 'budget' Socket AM1 2050 MHz Athlon 5350 Ubuntu and Xubuntu systems are loaded with 16 GB of DDR3 RAM.
You may have some older hardware lying around though....but will it run BOINC?
ARM boards as the Raspberry Pi2, 3 and 3+ are very limited in the expandability of system RAM (as in: "you just can't do it"): when you find out that the 1 GB of the Pi2 or 3 will not be enough, you should consider e.g. the 2 GB ARM Cortex-A53 equipped Odroid C2 or the 2 GB ARM Cortex-A17 equipped Asus Tinker Board. Both have the exact same dimensions as the Pi.
I had no trouble running Ubuntu Mate 16.04 on my 2nd Raspi 2 though, and I had an even more pleasant experience running it on the (faster) Raspberry Pi 3 -as I did with the Lubuntu for Arm on my 2nd Pi 3.