The efforts to mitigate the threat of the Meltdown and Spectre exploits appears to be WORSE than the threat itself. Many Intel systems will randomly and spontaneously reboot after installing microcode updates that protect against Spectre 2. No shit.
Slow computer got you down? Maybe a hardware upgrade should be in your cards, if so this guide to the Fundamentals of Upgrading a PC is an invaluable read. PCSTATS Tips