The heat output of the Athlon XPs

[donny_paycheck]

Alright, I've heard figures ranging from 45 to 75 watts and I'd like to know if anybody knows for sure what the exact spec is. The AMD website didn't have it easily avalable (of course) and all the big OCing sites didn't either. Anybody know or better yet, have a link to this information?

2nd note, I air cool an 80W peltier on my XP1800+ and it works great...only 10C or so full load at 1.75Vcore. This tells me it's not nearly as high as the tbird athlons, which were 80+ watts.

[Hoot]

The wattage of a CPU is a function of the speed it is run at and the core voltage. The higher the speed, or voltage, the higher the wattage. There is no fixed wattage across a range of speeds/voltages. It varies continuously. For example, my XP 1800 will run 1333 Mhz (under clocked) at 1.6V (50W), but my Tbird 1000 takes 1.725V (70W) to achieve the same speed. The XP 1800 runs at its stock speed (1535 Mhz) at 1.625V (61W) but in order to get my Tbird up that high, I have to use 2.05V (108W).

73, Hoot

[Voodoo Rufus]

If you can find the Radiate program around you can compute the heat output of a lot of processors. My Athlon 1400@1600 1.85V is about 94Watts according to that program.

[donny_paycheck]

ALL RIGHT! Believe it or not this is more info then I've had before. Thanks a lot....what I'm trying to do is calculate whether or not the 80W TEC I use will cool a 1.90+ volt athlon XP or whether I'll need a 120. If a 120, whether or not the MCX462 HSF will even work.

[Silver]

Donny, did not recognize the new avatar. Try this, 1.4 T-bird at 1.774 at 2.33v = more or less 150 watts. :eek:

[Hoot]

Originally posted by donny_paycheck
ALL RIGHT! Believe it or not this is more info then I've had before. Thanks a lot....what I'm trying to do is calculate whether or not the 80W TEC I use will cool a 1.90+ volt athlon XP or whether I'll need a 120. If a 120, whether or not the MCX462 HSF will even work.

Don't even think of cooling any kind of Athlon with only an 80W TEC. You'll find it will run cooler under load without the TEC. I would consider a 156W TEC to be the lowest you would want to use with an Athlon, either Tbird or XP. I have a 156W TEC and an MC-462A and using it with that TEC it was only about 3C cooler than without it at full load on a Tbird. At idle, it came down considerably. Substitue good Water Cooling for the MCX-462 and you'll have something then.

73, Hoot

[donny_paycheck]

Originally posted by Hoot


Don't even think of cooling any kind of Athlon with only an 80W TEC. You'll find it will run cooler under load without the TEC. I would consider a 156W TEC to be the lowest you would want to use with an Athlon, either Tbird or XP. I have a 156W TEC and an MC-462A and using it with that TEC it was only about 3C cooler than without it at full load on a Tbird. At idle, it came down considerably. Substitue good Water Cooling for the MCX-462 and you'll have something then.

73, Hoot

Yes, I wondered so but you confirmed my suspicions. The 80 watt module has worked so far at 1.75Vcore/1800mhz but before I go higher I wanted to make sure I wouldn't pass that sweet spot that'll turn the peltier against me i.e. when it becomes to weak to suck all the heat off the processor as fast/faster than it's generated. I think if I get the urge to raise the voltage then the pelt will make it's exit from the equation altogether, unless I decide to water cool.

[ButcherUK]

Try this http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/24309.pdf The XP data sheet from AMD, contains thermal specs for XPs.
A brief summary - 60W @ 1333 (1500+), 68W @ 1600 (1900+). Others fall in between.

[Kunal]

So a XP1900 OC'd to 1900-2000MHz @ 2.1v would dissapate roughly what?

Would a TEC 156w and WaterCooling suffice to get it to this speed (14 x 143(2-2-2 Agressive) @ 2.1v)

Current specs:

XP1900
KR7A-RAID
1024mb Crucial PC2100
PAL8045/Delta80mm 68CFM (35degC Idle/41degC load @ stock)

Tnx

Kunal

[Hoot]

I don't think you will have to worry about hitting that speed at that voltage, but if you could, you would be theoretically be dissipating 125W. That is more than you should attempt to cool with a 156W TEC. There is plenty of reading available on this. You just have to look for it. Also, you can download radiate.exe from the front page here:
http://www.overclockers.com/articles430/Radiate_Installer.zip
and the data file supplements here:
http://www.overclockers.com/articles430/RadiateData.zip

73, Hoot

[Silver]

Hoot, do you have him figured for 10 to 15 watts short on cooling ability?

[donny_paycheck]

I still need to change my sig, but the TEC is gone from my XP 1800+....it runs hotter at default but I can now take it to 1.85v and 150x12 (where it was at 1.75v w/the peltier) and it actually runs cooler. Seems like the pelt was putting a limit on the HS system. It held it's own at default but the extra watts from oc'ing pushed it over the limit and it ended up being a heater. I'm back to the swift MCX462 with just the 68cfm delta on it, but at 1.85v it's cooler. Looks like I need to get some water cooling action going on as soon as I'm done these other projects.