So for the past couple years I have been using UM on my laptop with a Celeron processor that maxes out at 2.4 GHz and 4GB of 1333Mhz ram (if you don't know what that means, it means it's very slow) however I did put a Mushkin reactor ssd in it and that sped it up considerably, but you still couldn't use most fully featured DEs very well at all,(just think that my parents had been using it with Windows ten when it had a hdd in it). HOWEVER all of that changed several weeks ago when I ordered a HP Pavilion 690 with a Ryzen 3 2200G, a Radeon rx 550 graphics card and 8GB of 2666Mhz DDR4 ram. What a difference!!!!!! Even though it has a Hard drive it's significantly faster than my laptop, like 10 times, what a difference a quad core 3.7 GHz at turbo makes from a dual-core one that at turbo or boost(whatever it's called) Is 2.4 GHz, I first installed stock Ubuntu 19.04 and it ran well, an impossibility with my laptop, then UM19.04 which I recently upgraded to the 19.10 beta, absolutely LOVE it, it has Windows on it, but I don't use it really ever, haven't booted it for weeks, and I don't even use the stock Ubuntu install either, though I love the yaru theme, and I actually like Gnome on desktop for simple things. Some people may ask why I didn't get the Ryzen 5 and a better graphics card, but I don't play games, it's cheaper, and I usually never come close to maxing out my CPU as it is, because the heaviest thing I run probably is a browser or ide, I may upgrade it to 16 GB of ram in the future and I plan to put a ssd in it. As far as hardware compatibility goes pretty much everything works except Wi-Fi, but Bluetooth does which I believe is part of the same thing so Idk why, however I have a USB WiFi dongle if I need it so it is no big deal. This review is late in part because I needed a new monitor and the first one appeared to be broke in shipping so had to be sent back, and while I have an old 1280 by 1024 monitor, that I really don't like, so I finally got my new 22" monitor which is the first 1080p screen I have ever had, all in all I love it, it far outpowers anything else I've had easily. It really is my "reasonable" dream for a desktop. My unreasonable dream would be a $60000+ Thelio computer from System 76
Congratulations, you must be feeling very, very happy.
So, getting your old laptop to do its best (now that you have a better daily-driver), consider this - try installing MX Linux on it - just to see if you find a difference - you can always re-install UM.
I have an old HP Netbook running MX Linux and it works well for a nine year old 32 bit system.
If you do try the experiment, let us know how you get on.
I've tried MX linux, it's just not my cup of tea and it runs well enough with UM, but the plan is to replace it in a month or two, I already have it's replacement picked out, after that I don't really care what happens to it, I may throw something like lubuntu on it with its old hdd in it and give it away