How to check for malware?

Did Firefox update about a week ago too?
Suggest go to Firefox page about:support and click on button Refresh Firefox
removes all third party plugins but not history,passwords etc

I have same Motherboard with x3 core Athlon and no speed problem in FF
maybe check Realtek LAN - mine uses r8169 driver, although device is r8168

No wifi to disable on this motherboard
Don’t disable Pulseaudio - FF will freeze if can’t playback audio
Can try PS2 connection for keyboard as well as USB

Try booting from Live USB used to install UM and see if have same problem there

Yes, I was going to suggest this also, and if the live session does not show the slowdown problem, you will want to try a full reinstall. Of course, there is always the possibility that the full reinstall works well at first, but later runs into problems after MATE does all it’s updates. If this happens, try again and go step-by-step by doing another full install and NOT selecting the “do updates during install” option. That way, after you make sure that the base install is working, you can then use the desktop ‘Software Updater’ to apply the updates singly or in groups, until you find whatever it is that is causing the slowdown.

Also, since other folks are running similar motherboard hardware and not seeing this slowdown, it pays to not overlook the obvious:

  • like first unplugging all possibly conflicting hardware.

  • and that, even with good quality compatible hardware, sometimes simple things like just plugging a Bluetooth or WiFi dongle into a USB3 port directly on your motherboard can make the device almost unusable due to USB3 to 2.4 GHz band interference (if this is an issue with your hardware you can often get around this interference by moving the device to a USB2 port, or by using a short USB extension cable, to relocate the device a short distance away)

  • or the fact that your WiFi signal can suddenly degrade, apparently for no reason at all, simply because a neighbor installed a new WiFi router which is operating on a channel or in a mode that is causing interference to your signal (often this can be fixed by logging into your router’s web interface, doing a channel scan, and manually overriding your router’s WiFi channel to one more widely separated from other strong nearby signals).

So, with luck, it will hopefully be something simple, but quite honestly, Ubuntu hasn’t been nearly the paragon of stability that it once was, so I would be prepared to do a little troubleshooting - but stick with it, and I think you will find that once you get MATE up and running smoothly, it was well worth the effort.

Reinstalling is no help to identify specific problem
But if Live ISO does not have slowdown issue is likely not hardware

Unlikely to be a USB3 problem as there is no USB3 on this motherboard

There is no wifi on this board, only gigabit LAN

No proprietary AMD driver for this GPU is no surprise - amdgpu does not support HD6000 series. fglrx is not supported on newer kernels, maybe was on 16.04 previously. Nothing to suspect a problem with open-source driver yet

No mention of wifi or bluetooth, or type of keyboard yet

Wasn’t aware there was an online Libreoffice version available yet, is this test/demo version?
is there some reason for using online version rather than installing?

There are flatpak and appimage versions of Libreoffice that do not need installing
they would be quick way to test an alternative Libreoffice

me too!
I have some more ideas on finding root of problem, but need more information back to decide what to look at next

I fixed the problem. I reinstalled UM 16.04. All works well again.

Thanks to all that that suffered through this problem.

mt