Will low power CPUs bring back TECs?

[Vinas]

So wait Jimbo say im running an 8600 which I am cooled with a apogee gtz your saying and 80w pelt would be sufficient to cool it near 0 or just below ambient under idle, I have a pelt I could use on this system I just didnt know if I could hook the pelt directly into my hx1000w without causing problems I love my psu too much to hurt it

Sorry to jump in but I've got an e8400 @ 4.4GHz on a 245w 12vdc TEC. So it's still possible and TEC isn't dead as most people think. It just takes a lot of preparation and research to put together a good TEC rig. No, a 80w pelt won't come close to working with your rig but maybe TWO would! Powering off the system PSU isn't recommended or for the faint of heart. But hey I do it. Then again I wired it up all special and stuff cause I didn't want to melt a $500 PSU

#1 reason to use TEC for me: I love the fact that my chip idles at -10c and loads about 30c.

[Uncle Jimbo]

Sorry to jump in but I've got an e8400 @ 4.4GHz on a 245w 12vdc TEC. So it's still possible and TEC isn't dead as most people think. It just takes a lot of preparation and research to put together a good TEC rig. No, a 80w pelt won't come close to working with your rig but maybe TWO would! Powering off the system PSU isn't recommended or for the faint of heart. But hey I do it. Then again I wired it up all special and stuff cause I didn't want to melt a $500 PSU

#1 reason to use TEC for me: I love the fact that my chip idles at -10c and loads about 30c.

Vinas - we were talking about an undervolted 320W or 340W TEC, not an 80W Qmax... and using the curves at a low percentage of Imax to limit the cold side. I am still getting parts to test this out but I think we will get decent performance, though not the low numbers you are getting. The 340 would run at 12V.

[Fitseries3]

i ran my crappy swiftech TEC block on my i7 for a few weeks. i got to 4.5ghz but heres a shot at stock...

[Vinas]

Vinas - we were talking about an undervolted 320W or 340W TEC, not an 80W Qmax... and using the curves at a low percentage of Imax to limit the cold side. I am still getting parts to test this out but I think we will get decent performance, though not the low numbers you are getting. The 340 would run at 12V.

I like the 320W undervolted idea a lot. My guess is that would be good for about 180watts @ full blast 12vdc so in theory it should work. Without calculating it out of course. TBH my favorite setup is the undervolted TEC sandwich. Sure it's a lot of work but the efficiency and capacity is really what makes it the way to go IMO.

[zipdogso]

I like the 320W undervolted idea a lot. My guess is that would be good for about 180watts @ full blast 12vdc so in theory it should work. Without calculating it out of course.

You missed Uncle Jimbo's point here... he was saying if you used it at 5v you could get an appreciable amount of cooling from it at a high COP and the current draw would be low enough to power it from a molex in your main rig. The problem will be fitting a 62mm TEC to the CPU, you will need to use both a cold and a hotplate and you will need to check you have sufficient clearance around the CPU socket. I havent checked the actual heat pumped at 5v but I assume since UJ mentioned it it would be high enough for an overclocked intel 2 core especially with their low TDP...which was the point he was making originally on starting this thread....he hadn't really intended to include i7's.

TBH my favorite setup is the undervolted TEC sandwich. Sure it's a lot of work but the efficiency and capacity is really what makes it the way to go IMO.

Are you referring to stacking TEC's ? You make it sound like you've tried it...but if you had.... you would know it doesn't work. In stacking the efficiency IS dismal and capacity is a joke, not sure where you got these ideas from. Stacking is only for very small TEC's, much smaller than any we use for computers. There is a anomaly in stacking TEC's that makes it use with TEC's we use pointless or indeed sometimes impossible.

Undervolting is best undertaken with single, high Qmax, TEC's connected in groups in series or parallel.

[repsol_23]

Uncle Jimbo:

Quick question. I am running that same pelt (340) from arcticspider but I am running it off of a meanwell 24V supply. If all things were kept the same, ie chip frequency, voltage, ... what kind of performance drop (in cooling) could I expect going from 24V to 12V?

Current specs:
x6800 @ 3.8 Ghz (1.46V)
2x mcr320 w/ 6 fans at ~1500 rpms (6V)
swiftech 350 pump ~ 4400 rpms
DD Cpu Block (s478 on a 775) cooling 340W TEC
DD Maze5 on HD3870 @ 877/1251
Thermaltake Toughpower 750
Meanwell 24V and 12V PSU's

Currently at idle my cpu gets quite cold (everest bottoms out at 5C) and my GPU hovers ~37C. I see avg. gaming (at least 2 hours) temps of 26C on CPU and no higher than 45C on GPU with an ambient of ~22C. This is with both blocks being in the same loop but running parallel rather than in series. The hotside of my block is usually ~46C with a max around 54C sometimes.

I know my temps will more than likely rise, but I was curious as to how much to expect (approximately of course). I would like to cut down on the amount of electricity I use but I still want to keep my cpu chilled. I don't run this machine 24/7 but more like 2-6 hours of gaming every other day or so.

[demonkevy666]

you need water cooling for this to work well ?
doesn't seem like this will work on air because of all the wattage.
this thread is an interesting.

[zipdogso]

you need water cooling for this to work well ?
doesn't seem like this will work on air because of all the wattage.
this thread is an interesting.

Yes water cooling is necessary really, with a TEC you aim to keep the hotside as cool as possible for most efficent running and air cooling is not really sufficient for TEC's with qmax over about 80W

Unless you go for the HUGH TRUE setup of course...

[Vinas]

You missed Uncle Jimbo's point here... .

No, I got the point just fine thanks. My point was that running this TEC at 12vdc while less efficient would give pretty good capacity for a decent OC. Use two of them in a sandwich... which leads me to below.

Are you referring to stacking TEC's ?

Again, no. Please don't assume I'd stack a TEC. That's just insulting. I was referring to a setup like the TRUE TEC sandwich. Air and TEC at it's best IMO. Well, besides the huge air cooler Jimbo likes to use that is... =)

[zipdogso]

No, I got the point just fine thanks. My point was that running this TEC at 12vdc while less efficient would give pretty good capacity for a decent OC. Use two of them in a sandwich... which leads me to below.

Again, no. Please don't assume I'd stack a TEC. That's just insulting. I was referring to a setup like the TRUE TEC sandwich. Air and TEC at it's best IMO. Well, besides the huge air cooler Jimbo likes to use that is... =)

Apologies Vinas...my vision of a sandwich was a bit skewed ...LOL.

But you have done it again here "Use two of them in a sandwich... " I realize you mean side by side...Yes that TRUE TEC cooler was great...2 of those 340's run in series off a 24V meanwell (12V each.) would give room for a bit of adjustment - slightly lower voltage for higher COP or slightly more a better pump. Havent got the exact chart for this but I believe if you can get a reasonable 10-15º delta the COP starts to rise noticebly below the 12V area..as you have 2 TEC's it might be preferable to sacrifice a few watts and run at 10v or thereabouts. (turn the 24V meanwell down almost all the way.)

[demonkevy666]

Yes water cooling is necessary really, with a TEC you aim to keep the hotside as cool as possible for most efficent running and air cooling is not really sufficient for TEC's with qmax over about 80W

Unless you go for the HUGH TRUE setup of course...

well my heat sink isn't getting very hot with my new phenom II 940 it's only gotten up to about 33C from both of the temperature probes i'm using. even with 1.55 volts the heat sink isn't getting hot the chip is getting quite hot at thos volts 62C. with my old 9850 at 1.55 volts this same heat sink with the same fans and temperature probes hit 41C. That chip hit 70C.

I don't think a true can hit my air cooling LOL
bye the way I'm using a sunbeam CCF with an sythe ultra kaze 3,000 (normal use 1000-2,400 rpm) plus there is a silneX 90 cfm fan at the read behind the heat sink.

[zipdogso]

I don't think a true can hit my air cooling LOL

LOL...If my memory serves well...the guy used two of them !!

[Uncle Jimbo]

Uncle Jimbo:

Quick question. I am running that same pelt (340) from arcticspider but I am running it off of a meanwell 24V supply. If all things were kept the same, ie chip frequency, voltage, ... what kind of performance drop (in cooling) could I expect going from 24V to 12V?

Current specs:
x6800 @ 3.8 Ghz (1.46V)
2x mcr320 w/ 6 fans at ~1500 rpms (6V)
swiftech 350 pump ~ 4400 rpms
DD Cpu Block (s478 on a 775) cooling 340W TEC
DD Maze5 on HD3870 @ 877/1251
Thermaltake Toughpower 750
Meanwell 24V and 12V PSU's

Currently at idle my cpu gets quite cold (everest bottoms out at 5C) and my GPU hovers ~37C. I see avg. gaming (at least 2 hours) temps of 26C on CPU and no higher than 45C on GPU with an ambient of ~22C. This is with both blocks being in the same loop but running parallel rather than in series. The hotside of my block is usually ~46C with a max around 54C sometimes.

I know my temps will more than likely rise, but I was curious as to how much to expect (approximately of course). I would like to cut down on the amount of electricity I use but I still want to keep my cpu chilled. I don't run this machine 24/7 but more like 2-6 hours of gaming every other day or so.

You are at about 75% Imax at 24V on that TEC. Dropping to 12V takes you to under 40% Imax. Based on the rest of your numbers, you are moving about 180W after 2 hours of gaming, and the temp is decent. At idle, You have way more cooling than you need.

You could do a simple 'bang bang' control by switching to 12V when you are at idle, and switch to 24V when the temp starts to run up (maybe 20C or so). The 12V setting will have plenty of cooling for light to moderate loads, and you will burn a lot less power - only about 70W. You are also at a very efficient operating point.

You can use any of the thermal fan control products to trigger a single pole double throw relay. Relays like that are available at radio shack and lots of other places, but you need to be able to switch 12A at 24V, so get a relay with 2 10A contacts and wire them in parallel. The TEC goes on the center (moving) contact, 12V to one pole and 24V to the other.

That will give you something like 10C at idle, and you would still get the same good cooling at high loads for your occasional gaming.

[Uncle Jimbo]

you need water cooling for this to work well ?
doesn't seem like this will work on air because of all the wattage.
this thread is an interesting.

I think with your cooler and a phenom II you might be able to do it with air - use the 340W TEC at 12V. I have not tested those phenom II chips yet, but from what I see from other testers, even at 1.55V you should see a 10C to 15C drop in CPU temperatures. That would certainly be good for the CPU and might let you get a better OC, and it's a fairly easy setup since you are only drawing about 5A on the 12V line - you can run it from a MOLEX connector.

I would agree with zipdogso's comment if we were talking about a 'standard' 16V TEC, but the 340W TEC is a 36V part, so you are undervolting to a very efficient operating point. Don't expect super cooling - but a 15C drop is still worth going after IMO.

[demonkevy666]

I think with your cooler and a phenom II you might be able to do it with air - use the 340W TEC at 12V. I have not tested those phenom II chips yet, but from what I see from other testers, even at 1.55V you should see a 10C to 15C drop in CPU temperatures. That would certainly be good for the CPU and might let you get a better OC, and it's a fairly easy setup since you are only drawing about 5A on the 12V line - you can run it from a MOLEX connector.

I would agree with zipdogso's comment if we were talking about a 'standard' 16V TEC, but the 340W TEC is a 36V part, so you are undervolting to a very efficient operating point. Don't expect super cooling - but a 15C drop is still worth going after IMO.

short run down of wattage used,cooler is smaller then mine (I think)
http://www.xtremesystems.org/forums/...d.php?t=213644

170 watts at 3.85ghz votls at 1.600.

btw i'm already running my phenom II at 3.755ghz @ 1.4875