Anyone here underclock a Dell Server before?
 

So I have an old Dell Server that I want to repurpose for use in my home.

I replaced the HD with an SSD to reduce noise, and thought I would run it with the top off with all fans disconnected for a completely silent machine, but it crashes after about a minute because the CPU, even with a giant passive radiator is cooking.

I don't need it to be fast, so I want to underclock / downclock the CPU to something where it won't fry without fans.

Any suggestions?

(And on a related note, the power supply seems to "know" if its own fans are connected or not, and won't run unless its fans are connected. Jeeezuz. Any ideas on how to defeat this?)

See if you can undervolt instead. That will make a much bigger difference to power draw and generated heat.

I know those tiny high RPM fans are super annoying, but I'm not sure you'd be able to cool completely passively; you would still need SOME airflow.

Not positive, but I think it's usually just a multiplier setting in your bios.

Undervolting lets you run at normal speeds. You're basically just reducing the safety margin between the default "reliable but excessive voltage", and "at the verge of crashing." Like overclocking, you change the value progressively until you have a crash, then go backwards until you're stable.

BTW a few years I picked up a 1RU server for about $USD 35... at the time I thought I'd grabbed a total bargain, but because of the noisy fans, proprietary heatsinks etc it turned out to be a real headache running it in the office. Better to part it out and sell off the bits on ebay. :)

drop a water block on it, i know you wanted no fans but that would solve the heat.

Thanks everyone .

I don't see a multiply setting in the bios. I did not know there was an undervolt. Is this in the bios too or is it a jumper?

Rowan : $35? That's a bargin for sure...! But yes if I can't solve the noise / crashing issue I will just sell it. I just need a small server anyway so I might just buy another Raspberry Pi 3 and use that instead. (Quiet and more fun!)

Cheers!

Not sure about Dell servers, but the "consumer" mainboards that I use have BIOS settings that allow you to manually configure the CPU and sometimes chipset (eg northbridge) voltages. There's no specific mention of undervolt, but there may be an overclock section. You may have to change something from Auto to Manual to see those extra voltage/frequency settings.