I used to have an ssd M.2 that came with my laptop, it was 128gb and normal performance (also had a 1TB HDD for storage), after a while i bought a new one with 512gb, but the performance somehow got worse, if the ssd is in usage it’ll slow quite a lot, to the point it has big lag spikes for 30 secs.

I changed to a Desktop PC a few months ago, also formated the ssd, thought maybe the laptop was the problem, but now its a bit worse, just downloading things in the browser lags the whole pc (As the browser first saves the download as cache in the ssd). I need a solution, i have 300gb i cant use because i have to install everything on the HDD or the 128 SSD and its awful doing so.