Peltier module cooling for fun.

[Kajzer]

Recently, my friend got Phenom II X6 machine for free.So we thought about doing something crazy with it. From what I heard those cpus tend to be good at overclocking so I thought about building sick cooling for it (just for fun, I know that practically it will suck). Right now we have 360mm radiator,cheap water block, 20W pump and 6 fans (push-pull), Also the radiator is outside the window so it makes pretty good temperatures. However we would like to make it even better. Does adding peltier module between cpu and block make sense? If so, which to buy and how much difference we can expect?
Sorry for my english

[-rascal-]

Well...good at overclocking for it's time in 2008 ~ 2010.

They go up to 4.1 GHz ~ 4.3 GHz on high-end air cooling / liquid cooling.

That is if you get a decent chip, otherwise, 3.6 GHz ~ 3.8 GHz / 4.0 GHz range.

Dumping extra voltage onto it won't help -- that is like the wall these chips hit.

Of course, anything can go higher with LN2, Dry Ice, etc...

 

I had a Phenom II X6 1090T, paired with a ASUS Crosshair IV Formula / Crosshair V Formula (non-Z).

 

As for peltier coolers...you need to dump a lot of power into, to get it to cool decently.

E.g you need to input 300W (or even more!) worth of power to make it cool 200W.

You need to electrically bias one side, heat up one side, to make the opposite side cold.

At that point...you are sucking 200W of heat off the CPU, but pushing 300W worth to the CPU cooler / water block side...

Peltier coolers are inefficient.

[Kajzer]

2 minutes ago, -rascal- said:

Well...good at overclocking for it's time in 2008 ~ 2010.

They go up to 4.1 GHz ~ 4.3 GHz on high-end air cooling / liquid cooling.

That is if you get a decent chip, otherwise, 3.6 GHz ~ 3.8 GHz / 4.0 GHz range.

Dumping extra voltage onto it won't help -- that is like the wall these chips hit.

Of course, anything can go higher with LN2, Dry Ice, etc...

 

I had a Phenom II X6 1090T, paired with a ASUS Crosshair IV Formula / Crosshair V Formula (non-Z).

I have somewhat unrelated question. Why using for example LN2 cooling makes overclocking limits so high? Is it only because of the temperature? Or something else?

[Kajzer]

5 minutes ago, -rascal- said:

As for peltier coolers...you need to dump a lot of power into, to get it to cool decently.

E.g you need to input 300W (or even more!) worth of power to make it cool 200W.

You need to electrically bias one side, heat up one side, to make the opposite side cold.

At that point...you are sucking 200W of heat off the CPU, but pushing 300W worth to the CPU cooler / water block side...

Peltier coolers are inefficient.

Yea I know they are inefficent, but I would like to try it anyway, would 360mm rad with 6 fans keep up with it?

[-rascal-]

6 minutes ago, Kajzer said:

I have somewhat unrelated question. Why using for example LN2 cooling makes overclocking limits so high? Is it only because of the temperature? Or something else?

 

Temperature mainly.

Air / liquid cooling, you are limited to as low as ambient / room temperature ...or somewhere around that...you cannot physically go lower...

You go below 0*C with Dry Ice / LN2.

Sub zero temperatures also has an effect on the CPU regarding to the silicon die / electronics / current / voltage.

Chips behave differently when -40*C or -75*C compared to the usual operating 10*C ~ 90*C.

 

That and overclocking a chip, when pushing it to the max is NOT linear.

For an example, using the Phenom II X6 1090T....let's say

• 3.6 GHz ~ 4.0 GHz -- for every 0.1V you add to the Core Voltage, you gain 0.1 GHz
• 4.0 GHz ~ 4.3 GHz -- for every 0.4V you gain 0.1 GHz.
• If you go up to .... 5.5GHz+, it may be every 1.0V you gain 0.1 GHz

It's exponential.

 

My FX-8350 was a good example.

4.5 GHz ~ 4.7 GHz, below 1.4V easy.

4.8 GHz I could run it with 1.4V Core Voltage.

4.9 GHz I needed 1.45V ~ 1.47V.

5.0 GHz / 5.1 GHz I was pushing 1.5# V MINIMUM...

[-rascal-]

9 minutes ago, Kajzer said:

Yea I know they are inefficent, but I would like to try it anyway, would 360mm rad with 6 fans keep up with it?

 

360mm radiator will be plenty for a Phenom II X6.

I was able to tame the temperatures with a high-end tower air cooler.

Even easier with my 240mm radiator.

 

You will hit the frequency wall of the CPU (45nm Thuban architecture) before temperature becomes the limit IMO.

If you're dumping in the range of 1.5V into the CPU, and you are not gaining any extra MHz, that's the limit of the chip.

[Kajzer]

2 minutes ago, -rascal- said:

360mm radiator will be plenty for a Phenom II X6.

I meant about cooling the Peltier.

[-rascal-]

3 minutes ago, Kajzer said:

I meant about cooling the Peltier.

 

Oh, that will depend on the spec (e.g spec sheet) of the Peltier cooler you are using, and HOW you have it set-up / HOW you are going to use it.

Gotta determine how much heat you are making it generate...

Then see how your 360mm set-up is done...

 

Depending on the manufacturer / brand / model / material of the Peltier you are using, specs can vary...

[Kajzer]

1 minute ago, -rascal- said:

 

Oh, that will depend on the spec (e.g spec sheet) of the Peltier cooler you are using, and HOW you have it set-up / HOW you are going to use it.

Gotta determine how much heat you are making it generate...

Then see how your 360mm set-up is done...

 

Depending on the manufacturer / brand / model / material of the Peltier you are using, specs can vary...

Oh. Okay, I've calculated that to achieve anything practical, I would need 200W Peltier like this: click
That would make 200W+125W=325 Watts of heat being outputted to the radiator, am I right? How can I calculate the maximum output power of a radiator?

[Kilrah]

Even a 550W Peltier wasn't able to cool a CPU with similar TDP:

 

 

[-rascal-]

13 minutes ago, Kajzer said:

Oh. Okay, I've calculated that to achieve anything practical, I would need 200W Peltier like this: click
That would make 200W+125W=325 Watts of heat being outputted to the radiator, am I right? How can I calculate the maximum output power of a radiator?

 

If you look at the spec of THAT peltier cooler...when it biased using MAX current, and MAX voltage, it is 200W/224W.

13A x 24.1V = 312W heat generated from the hot side of the peltier cooler...to be able to cool 200W worth of heat.

Another problem, how are you going to supply 13A and 24V?

It is 312W PLUS heat generated from the CPU.

 

Maximum cooling capacity is when there is a 0*C temperature different between the hot and cold side of the peltier.

So...if you cold side (CPU side) is 50*C, and your hot side (water block side) is 80*C ... difference of 30*C your cooling capacity dives to ~125W, from 200W.

Assuming you are powering the peltier with 312W of power.

 

Spec sheet mentioned their numbers are collected with the hot side being held stable at 27*C for 200W cooling.

 

 

[Kajzer]

3 minutes ago, -rascal- said:

Another problem, how are you going to supply 13A and 24V?

That's not a problem for me. I have strong power supplies.
 

 

5 minutes ago, -rascal- said:

So...if you cold side (CPU side) is 50*C, and your hot side (water block side) is 80*C ... difference of 30*C your cooling capacity dives to ~125W, from 200W.

Assuming you are powering the peltier with 312W of power.

I don't think that hot side would be 80*C. Radiator is outside and right now at my place outdoor the temperature is -5*C. I know that water will be much hotter than -5*C but it certainly wont reach 80*C.

[-rascal-]

1 hour ago, Kajzer said:

That's not a problem for me. I have strong power supplies.
 

 

I don't think that hot side would be 80*C. Radiator is outside and right now at my place outdoor the temperature is -5*C. I know that water will be much hotter than -5*C but it certainly wont reach 80*C.

 

What kind of power supply...are you using?

ATX PSU is +12V

You would ideally, want a lab PSU, where you have a knob to adjust the voltage and current limit, etc.

13A through thin hobby electronics wire is not going to cut it...

 

Well...that will depend on how much your radiator can pull heat away EFFICIENTLY from the hot side of the peltier cooler then.

Sure the outside temperature is -5*C, but what is the coldplate / liquid temperature?

It certainly won't be -5*C.

 

Something like the Enermax LiqTech TR4 is rated for ~500W TDP?

And that's a 360mm radiator AIO.

 

Let's assuming your AIO liquid temperature is 45*C (can be typical when a CPU like a i9-9900K is overclocked and under heavy load with 25*C ambient temperature).

But -5*C outside...let's assume liquid temperature is 25*C then.

25*C to whatever your CPU temperature is...which gets you the temperature difference....then how much the peltier is able cool.