Pelti Probs

[Guest]

Ok I have a cB0 stepping P3 700e slot which i can get up to 820 right out of the box stock fan. changing the voltage only causes heat problems so i got myself a Peltier. Now i have a 250w power supply when i installed the peltier the cold side wasnt very cold but the hot side was extremely hot thinking its defective i sent it back got a new one then tried again same result i had to under clock to 566 to run at a fine temperature. Is it just the peltier or is it something else?

---==EDITED==---

adding to what i said the peltier normally is attached to a heatsink with 3 fans when i bought it and believe me the fans dont stand a chance against the heat i even added two huge case fans behind the cpu to push the heat well little helps there too like i said if anyone thinks it might be the power supply r just the way this peltier was made let me know thank you <P ID="edit"><FONT SIZE=-1><EM>Edited by Togra2o2 on 01/31/01 00:38 AM.</EM></FONT></P>

 

[Guest]

I had a peltier that increased my temp 10c, If you run it for a long time it should get really cold, it also could be your power supply.......the peltier I got now lives it's life as a beer cooler.

 

[TheSandman]

When running a pelter you need a good heatsink to remove the heat from the hot side I am talking pep 66, fop38.

SANDMAN

 

[TheSandman]

Was not done yet oops. If you are using some cheap oem heatsink the pelter will not work as well also use thermal past between the pelter and heatsink. Hope this info helps you.

SANDMAN

 

[Crashman]

Wow, why didn't you just try a better heatsink first? I use the stock LARGE cooler (from the PIII 933) on my 700E without any problems at up to 980MHz, but I run it at 933 because it can run at slightly lower voltage levels that way, hopefully extending the life of the CPU.

Suicide is painless...........

 

[gregorarch]

Sounds like your peltier is underpowered. The calculations for peltier sizing are a bit involved, but if you don't do them this is what happens. What wattage is that peltier and what's its deltaTmax? What's the heat load from your CPU?

I've been thinking about peltier cooling for a while, but if you do the math you find out that you need a 80+ W peltier with an unusually high deltaTmax to cool a K6-2...

If you look on www.overclockers.com they've got a few articles about peltier sizing.

 

[Guest]

I have a 72watt peltier asuuming this should i get a 300 watt power supply or 400 watt? cause i mean the 400 watt is pricey but the 300 is within price range and if thats wall it takes then i guess all i have to do is upgrade to a 300watt powersupply.. right?

 

[gregorarch]

Ideally you'd want to run it off an independant PSU. However, that isn't likely to be the problem. If you are using your computer's PSU you are limited to 12V, but your peltier probably wants 16V, so you're only running it at about 50 W - which is nowhere near enough even if you have a very high deltaTmax (more than 71 deg C is high).

You MUST do proper power calculations based on thermal load, pelier power and deltaTmax, and thermal conductivity of your heatsink. If you don't do the math you're wasting your time. If the thermal load of the CPU is more than the peltier/HSF can handle then you're just putting an extra heater in there.

 

[ejsmith2]

Sounds like you've got an under-powered peltier.

I used my old 200Watt ATX power supply for a 84W peltier and FOP38, at least for a while...The 200W was only rated at 6Amps on the 12V rail, but it brought down my cpu temp to 35C.
Along those lines, the 200W p/s lasted about 14 days running non stop. I put in a new 300W p/s, and get temps around 17C with a T-bird 850 @ 1000.