I said disk usage, not CPU usage. On modern systems, CPU is rarely the cause of FPS drop. Instead, usually the bottleneck is the GPU (lagging all the time then) or in some cases the disk usage (occasional lag spikes). Depending on how the settings are on your PC, doing disk I/O may slow down the computer.
To test it, compress a large file using winrar, around 500 MB or more, using maximum compression to be sure
To test it, compress a large file using winrar, around 500 MB or more, using maximum compression to be sure