What happens when you underclock your CPU/RAM?

[KaminKevCrew]

I've been interested in computers for some time now, but a little while ago today, I was struck with a question: What happens if you turn down the multiplier to 1 on a cpu? What happens if you lower the base clock the processor runs at to whatever the minimum is? What happens if you do both at the same time?

 

I'm genuinely curious, and if anyone knows/has tried this, I'd love to know what happens and if there are any compatibility issues with RAM or if you could fix it by adjusting RAM clock appropriately.

[themctipers]

it can't go to 1 because the lowest is 4 or 8x

if you do, it gets slower.. sometimes my laptop goes down to 800mhz when resuming from sleep. can't do shit basically.

I know you can 'fix' broken ram by running it at lower clocks with worse timings, as in make it more stable from a unstable mess if you really need it to work, did that for a while and it still is painful. 

[aezakmi]

The CPU wouldn't run at 1x the speed of the FSB, in some chips the minimum might be 4 or 8x (for AMD is 200MHz and for Intel 100MHz, and the minimum CPU freq is 800MHz)

that way it'll use less power and generate less heat, underclocking/volting is useful for passive cooled systems like NAS builds that don't need a lot of raw CPU power to work but rely more on network and hard drive speeds

you can lower the memory speed in MT/s to achieve lower latencies

[SZ1357]

On 7/18/2018 at 11:41 AM, KaminKevCrew said:

I've been interested in computers for some time now, but a little while ago today, I was struck with a question: What happens if you turn down the multiplier to 1 on a cpu? What happens if you lower the base clock the processor runs at to whatever the minimum is? What happens if you do both at the same time?

 

I'm genuinely curious, and if anyone knows/has tried this, I'd love to know what happens and if there are any compatibility issues with RAM or if you could fix it by adjusting RAM clock appropriately.

I just don't recommend doing this but I understand it's just a question anyways. But because on newer technology (previously mentioned like SpeedStep, Turbo boost etc.) this isn't really necessary, except if you're cooling system can't hold it's base clock, then I guess you could change it by a few milivolts to improve cooling just a tad, but that's really the only beneft.