My first job was building computers with old parts. A guy needed MS Word for work but didn’t want to buy a new computer or upgrade his 386SX (25Mhz iirc). It had like 20MB of disk and I don’t recall the RAM. So he asked me if I could try. So I did. I managed to install DOS, Windows 3.1 and MS Word. I don’t remember how long it took to boot, but I remember that it would take 6 seconds for a pressed letter to appear on the screen.
With the introduction of CPUs which ran faster than the original 4.77 MHz Intel 8088 used in the IBM Personal Computer, programs which relied on the CPU's frequency for timing were executing faster than intended. Games in particular were often rendered unplayable, due to the reduced time allowed to react to the faster game events. To restore compatibility, the "turbo" button was added.[4] Disengaging turbo mode slows the system down to a state compatible with original 8086/8088 chips.