Plecostomus, - try increasing the default Sleep() setting until your FPS drops to around 60ish.. - It will benefit your CPU usage,
considerably!
On my modest system, lowering the Sleep() to '1' can give as much as 190 FPS, (in Windowed mode),
but with 100% CPU usage!!!
The default Sleep(10) setting produces about 112 FPS and registers around 60% CPU usage in the Task Manager.
Increasing to Sleep(20) produced about 52 FPS and registers around 25/30% CPU usage. - Your setup of course may be different.
As others have said though, the best thing to do is change the Sleep() setting until the FPS drops to about 60, - any more than that is pointless and will only contribute to over-heating. - On my system I find that Sleep(17) gives me around 63fps.
BTW, - Welcome to another UK member to the forum!