Is this REALLY overwhelming my TEC?

[charlie]

I'm a bit dismayed by the performance of my MCW5000PT...226w tec. I run an open loop system in a 5 gallon bucket strictly for benching. When I fill the bucket with 10# of ice and 2 gallons of water, my BIOS temps plunge down to N/A.
But when I get the cpu working @ 1.900v, 2.66@3880 I run 1 benchie of 3DMark and run at 20C. So, In 7 minutes or whatever, I'm going from -3C (?) to 20C. BTW after the benchie the water in the bucket is still 4-6C. It almost seems like the 226w pelt can't keep up with the heat from the cpu??Guesses? Bigger hose MORE pump? ???????????????????
Is this correct? Would I have better numbers if I was running chilled water through a NON-TEC waterblock? See, if the TEC can't keep that thick coldplate cool...maybe chilled water 2mm from the cpu core would?
My Rig,
MCW5000PT
40a 12v PSU
Stock 3/8 tubing ID
RIO 2500 powerhead 2972 l/h (much lower using thru WB)
Abit IC7
P4 2.66
AS3 TIM

[KnightElite]

How much ice, exactly, are you putting in this bucket? Put in lots, and lots, and lots of ice if you want it to work.... that TEC + your CPU + pump, etc.. is going to be putting something like 400 or 500W into the water. That's enough to heat it up pretty damn fast.

[mdzcpa]

charlie,

Be aware that the temps on the IC7 are reading 8-10c too high. This is known issue on the IC7. Abit has informed me that a BIOS correcting the issue will be coming soon.

So if you are going from n/a to 10c, then that's not nearly as bad:)

[Major]

Charlie do you have any Swiftech 1/2 " barb adaptors for your block ??

I would think that no matter how big your pump is, the 3/8" hose would be really really restrictive. especially if your using a 3/8" barb on the pump inlet and outlet. Increasing the hose to 1/2" ID and using 5/8" barbs on the pump would greatly increase the flow.

Your using a 40A 12v psu for the tec, are you sure its operating correctly ??

[charlie]

Major,
1/2" adapters...will do.
12v PSU? I hope it's working ;)
C

[charlie]

Originally posted by KnightElite
How much ice, exactly, are you putting in this bucket? Put in lots, and lots, and lots of ice if you want it to work.... that TEC + your CPU + pump, etc.. is going to be putting something like 400 or 500W into the water. That's enough to heat it up pretty damn fast.

Knight,
I'm throwing 1 - 8# bag of ice into the bucket w/2 gallons water.
The water is straight out of the tap (Yeah, I know...naughty me, no protectants) maybe 20C...
But whaddya' think? Is the "cold" getting through the coldplate onto the cpu? Would direct contact with a thinwall wb be better?
Now during normal use, this rig works well, even with warm water in the bucket, my temps stay sub ambient doing low load stuff...
MDZCPA,
Thanks, that makes me feel better!
C

[rabeb25]

run it off of the cpu and see if it frosts, with a 226 it should frost super fast if its working propery. I just had the same exact problem, and my pelt had gone bad, under any load, temps would skyrocket.

[]JR[]

Running your tec @ 12v is your problem, (23.8/15.2)*12*12*0.6 = 135watts of cooling power, which with a big loaded overclock too brings your dT to around -10 to 5degrees, which is rubbish tbh. (dont have the performance graphs on this pc unfortunately)

In terms of seeing the coldplate frost up any tec does that look at a pic i did a long time ago using a full power 172watter and an alpha 8045

http://www.phjrw.34sp.com/ac172c.jpg

And the 3/8"s barbs arent really going to help you either, flowrate is king where tecs are concerned.

So first I would up the voltage to 13.8v-14v and change to 1/2" pipes...

]JR[

[mdzcpa]

JR has a point. I have found the best voltage for running the Swiftech MCW462-UT w/ 226w TEC was 13.2v. that seemd to be the sweet spot. 12v may be too low.

[Jeff]

This thread is great since I am in the process of putting together a very similar system. Great bit of information here. :toast:

[]JR[]

Forgot to add that them fans cooling my alpha are 380cfm 240vac toriod fans, and theres two of them. So aircooling tecs isnt really possible :)

]JR[

[Pimpsho]

when u say 12v is to low what are you talking about? the +12v? also isnt a 226tec require a 25a dedicated psu to work properly?

[]JR[]

18.8amps @ 12v, but no im talking the cooling power of a 220w isnt 220w @ 12v its what i said in my above sums. And its too low for modern cpu cooling, since as pumped heat increases dT drops exponentially...

edit the big 100 for me is up tonight...

]JR[

[KnightElite]

Yeah, different voltage means that the TEC will cool a different amount. Basically, it will move 226W of heat if you run it at VMax. It will move less if you run it at lower wattage, but it will also generate less additional heat.

[mdzcpa]

Originally posted by KnightElite
Yeah, different voltage means that the TEC will cool a different amount. Basically, it will move 226W of heat if you run it at VMax. It will move less if you run it at lower wattage, but it will also generate less additional heat.

Well said. Most 226w TECs max cool at 15v. I've found that there is a sweet spot for every system. Too low of voltage and the TEC does not cool the coldplate enough. Too high and water temps sky rocket and you lose efficiency and face diminishing returns. When that happens all you do is throw a lot of hot air around your case and work area with little improvment in temps. I like to use an adjustable dedicated TEC PSU and turn up the voltage to the point that I see efficiency start to nose over than stop there.

[Pimpsho]

would u guys get the meanwell psu over this? http://www.etronics.com/product.asp?stk_code=pyrps36kx

[mdzcpa]

I've used that same PSU myself with excellent results:) It's not an extreme PSU, but it makes a good choice for those getting into pelt cooling. Unless you have some serious water cooling capabilities, you'll never need a PSU that runs flat out at 15v. That meanwell does 12v, but is adjustable plus/minus 10%, so you get a range of 10.8 to 13.2v. Anything around 13v is where that 226 what will be at it's best efficiency with typical water cooling.

EDIT- woops...i thought that link was going to be pointing to the meanwell S320. that's a pyramid psu in your link.

[Pimpsho]

so which one would u get then? the meanwell is more and can fit in the case if thats a factor but also doesnt put out as much amps since the meanwell can only goto 13 or so and this one can goto 15v and 25a

[mdzcpa]

I have no experience with that pyramid so I cannot really comment on it.

I like the meanwell because it can fit in a standard ATAPI drive bay for nice finished look. Since most 226w TECs do best around the 13v range, I feel the sacrifice of a 13v max was worth being able to conceal the PSU.

If your water cooling is up to it, running a higher voltage (eg 15v) will help make colder temps, so it is a personal choice. Just make sure your WC system has enough power to cope with the extreme heat the 226w TCE will produce at 15v.

[CSOFT]

On the Pyramid things I'v used (500w amp/15"Sub) I'v never had any problems in terms of quiality.

[Marci]

Righty... from twiddlin on me Meanwell with a multimetre in hand, I get a range of 10v thru to 14.2v... Currently run my 220w TEC at 13.6v (can't remember who posted it but was a while ago... saying was optimum voltage for this tec)

At the mo I'm runnin at 7 on core, 17 ambient.... XP2400 clocked up at 2400Mhz, 12x200, 1.85v, NF7-S Rev2 with latest beta bios. That's with me rad fans down at 6v for silence... and the same watercoolin on the tec also coolin NB and GPU.

[charlie]

Tec guru's,
Well I think I may have found the key...
Remember the prob was that I could hit negative temps at idle, like -3C but when you sneezed on the pc...like surfing intrnet...
it jumped like 10 degrees. Like 25 when loading hard...
Well, I measured the PSU outputs when the rig was loaded...
11.40v
So...I guess why that explains why it won't hold a temp worth a cr*p...right? Since I only bench with iced water, I'm gonna' buy a new adjstable PSU that allow me to dial in 13.6v++ up to 15v.
Seems to me that others are reporting loaded temps of -10ish with Prommies...might get close with optimized TEC's right?
C

[kchip]

I tried 3 PSU's with my 226 Swifty. The more voltage ( 13-15v) the hotter the water gets in a shorter amount of time. Sometimes the water got so hot the block was radiating heat to my NB ( 37-39 C ouch )

I could not find a decent middle ground.

I bought a 156 W and swapped it with wonderful results. 15 - 20C loaded @ 1.85 @ 2466

[jinu117]

Yup the extra voltage will matter a lot once you start pushing the limit of your tec. .5v on my previously tec set up made as much as 7c load temp difference! I believe 13-13.5v is the sweet spot for MCW-5000PT if you can figure out how to dump the heat it generates :P

[charlie]

You know what Swiftech did to test it's MCW5000pt?
They simply attached the WB to the faucet and opened the valve...lol...like 15C water, might work for short term benching.
However I've had enough of the TEC hassle and am going phase change
C