Speed boost on a budget?

So my dear old Dell XPS is more than 6 years old now. It was a well spec'd machine when I got it, with quad core i7, 16GB, SSD etc and it's not disappointed me. But recently it's felt like it's been getting a little slower, getting hotter, working harder than I remember. I've been having to close all applications and do a proper re-start to clear memory before doing any Lightroom work, and when I exported images into another program like silverEfex of On1 then the fans would wind up and it would struggle a bit. Made me think than another year or 2 it would be time for an upgrade.

Came across an article recently about thermal paste drying out & becoming less efficient after a few years, and it made me wonder. Came across an offer for Arctic MX2 thermal compound, then read up about XPSs and thermal throttling & it seemed like a good idea to remove any internal dust & replace the thermal compound. Took all of about 20min.

Now it's like a new computer when under load. I've been editing & uploading, got lightroom, On1 Photoraw, Luminar and firefox open at the same time & the fans have just become audible - before they'd have been whistling away by now & everything would be a little laggy through throttling. There's a fair bit of heat being generated, but the fans are just one notch above baseline. This has to be the cheapest peformance boost I've ever seen, and if you can't tell, I'm seriously impressed.