Question PC slows to be unusable after downloading 15+GB

Aug 13, 2020
when i download game on any client (Steam, Epic, Uplay...), after cca 15+GB, PC starts to be noticable slow, lets say after 30GB it is very slow and after 50GB it is unusable, talking about being in windows, when i click on anything, it takes also time to light up the button, or it just appears freezed.
It persists since i had two HDDs (one with windows), swapped one for SSD (installed windows on that) and kept using second one. After some time fried second HDD and bought new HDD. The issue is present also with these new drives. I have to restart or reset PC then it works normal again.
MB: gigabyte z97-x Gaming 3
CPU: i5-4690K 3.5 GHz
RAM: 16GB Kingstons (4x4)
SSD: Intel 128 GB (free constantly around 10 GB)
GPU: nvidia 960 before, 2070 now
PSU: 850W
Any idea what this might be caused by? Did i damaged MB during any replacement or is this SW issue? I am not sure but might be present since i built this PC, dont really remember. Thanks.


I'd say if only having 10 GB of free space on an SSD, you are going to have issues with downloads with sizes greater than 5-8 GB....; that data has to buffered somewhere before and while being written...

WIth quality 500 GB Crucial MX500 SSDs about $65 these days, I'd start there.