I'm trying to install either Pinguy OS or Ubuntu dual booted with Windows 8.1 on my main machine. When I boot into the live DVD of either, I can't use my mouse and keyboard. I have a Gigabyte 990FXA-UD3 rev3 motherboard, a Logitech G510 keyboard and a Mad Catz RAT 7 gaming mouse. Am I going to need to buy PS/2 peripherals to accomplish this, or is there another answer?
Try plugging your mouse n keyboard into your non usb3 ports.
USB3 may not be enabled, I am unsure of the state of their kernels as Ubuntu is far behind Arch, just plug into USB2 if that does not work the change distro to avoid headaches, or go PS/2 route.
I tried a RAT7 on linux and it didn't work without editing some config files (I can't remember off the top of my head). You should google about using that keyboard and mouse on linux and how to get it working, but you might need to find another keyboard until you get it set up.
The Mad Catz mouse has some issues with drivers in Ubuntu (well Linux in general) with 9/10 times requiring you to manually edit the peripheral configuration, uunfortunately something you can only do after installing the os.
The keyboard maybe facing similar issues as it is the least keyboard, keyboard out there.
The install relies on basic drivers to get it through (so it has the widest compatibility with devices) so devices with "gamer additions" aka extra buttons, screens etc rely on more complex drivers that aren't loaded.
Both that keyboard and mouse are class compliant and should just work.
Maybe try another distro with less issues.
My wife uses a RAT 7 on Manjaro on a Gigabyte mobo, she used to use exactly the same mobo as you have before without any issues, and now she uses an Intel socket Gigabyte mobo without any issues. Should just work right out of the box.
Maybe it's something to do with ubuntu, I tried this on a friend's computer with his RAT 7 and linux mint and the mouse would not work without modifying a config file (pretty sure it was something to do with X11 but it was a while ago and I'm only reminded of it because of the OP). I don't see why the keyboard wouldn't work though.
As Zoltan said, they should work out of the box. But it has been along time since I've gone near Ubuntu for my own needs, but I did have this issue before (like Ubuntu 10.10 days)
Maybe this helps: go to the BIOS and enable IOMMU.
I had a Gigabyte GA-990XA-UD3 (the cheaper model) and for some reason none of my HIDs worked in linux if IOMMU was disabled, never found out why.
I've had the same issue, so I've just been living in windows while I look for another distro.