How are you supposed to do that?

First check if your motherboard has Turbo switch jumper and use that instead.

It's generally safe to underclock a CPU by lowering the multiplier. Do you know what the bus speed and multiplier is currently set to?

If the bus speed is 33 Mhz and it's a 3x multiplier, you would need a 1x multiplier to get you to 33 MHz on the CPU. Make sure your motherboard has jumpers/DIP switches settings for that.

Just don't accidentally raise the voltage.

The motherboard won't have jumpers for 1X, because in 486s the multipliers hard hard wired into the CPUs. The DX4 only supports 2X and 3X. If you want to get 33MHz, you'll have to drop the FSB down to 16MHz.

Your best option is to use the turbo switch (if your motherboard has one - most did).
A DX4 100 MHz, with the turbo off, drops to around DX33 MHz speeds.

Thanks for the replies! The lowest i can get with jumpers is 60 mhz (which did work ok). Its a compaq that does not have a turbo button on the case so im not sure if the motherboard will have it ill have to look.

If the BIOS provides an option to do so, turning off L2 or L1 cache could be an option.

Anonymous Coward wrote:

The motherboard won't have jumpers for 1X, because in 486s the multipliers hard hard wired into the CPUs. The DX4 only supports 2X and 3X. If you want to get 33MHz, you'll have to drop the FSB down to 16MHz.

Some are hard wired to 3x but some could use both 2x and 3x multipliers:
https://en.wikipedia.org/wiki/Intel_DX4

Simplest(?) way could be just to swap CPU for 486DX-33.