how much difference will it really make?

[Pirate_Freder]

how much difference will it really make?(cascaded peltiers )

so i'm at the final decision, i've asked a lot of questions around here and other places and i just have one more qusetion? (i hope ) how much difference will it make if i get my cpu into the 0-8C range in terms of my clock ceiling? i was informed by ViperJohn that with my two dual heater cores and evercool 120mm 80cfm fans i could get into that range at load wuth the swiftech mcw5002-64t
running at 12.4v. oh and also in my loop will be an mcp655.

thank you very much everyone you've all helped me out a lot and i'm finaly getting my system together

 

[Ad Rock]

That is a impossible question to answer really. It really just depends on your individual chip.

I do know that usually you see a 200 to 400 mhz gain (on average) when going from watercooling to DD phase-change. Hard to say what going down to 5c would do really.

 

[infinitevalence]

very true, YMWV, but an aproximation that I have seen used before is 10mhz for every 1c.

 

[Pirate_Freder]

hmm, well if i hit around zero then i guess it should be quite the improvement .
oh and Ad Rock, in terms of the individual chip, i've got an opteron 148 socet 939 which should be here tomorow and newegg told me will be cabne stepping so what kind of difference do you think there?

 

[Pirate_Freder]

uh oh, i just realized, i forgot to ask . would you guys agree that the swiftech 5002 is the best waterblock for a peltier (going to get their peltier kit so i can get that blocl)?

 

[infinitevalence]

no such thing as "Best" what your really asking is; is the 5002 a decent block, yes its a decent block. the 6000 series are better but you cannot get the full pelt setup.

 

[Pirate_Freder]

well yes this is true, but by best i guess i kind of meant in opinion. and i don't mean decent , i mean excellent , i of course want to get the most out of this so i want the best i can get and i'm willing ot pay for it(given the performance is worht the price and it doesn't cost as much as phase-change ).

 

[Pirate_Freder]

oh yeah and also i do want one that comes ready for a pelt (cold plate etc.) so i guess it comes down to maze4-1 and swiftech 5002 or of course if anyone here knows of somthing better.

 

[infinitevalence]

then look at the SwiftTech Apogee, with a good rad like the Blackice Extreme 2/3 or Thermochill 120.2/3. You can figure that your going to need to spend ~250 for high end pelt cooling.

 

[Pirate_Freder]

yeah, i know what i'll have to spend and i said i'm willing to.

 

[LabRat23]

I thought the apogee is too small for a pelt. The overall size might be just enough, but the internal pin footprint is smaller than the 5000 or 6000.

The rule of thumb that always worked with me is 2 to 3% faster with every 10C drop.

 

[Revivalist]

@ LabRat - But the apogee doesn't come with mountings for a cold plate. It's not made for a pelt out of the box.

@ Pirate_Freder - I see you already hit 2.678GHz at 2V Vcore. Is that stable through SuperPi, occt, Prime95, etc.? I don’t think you would be able to reach much higher than that even if you drop temps to 0-8C. My guess would be you might be able to do 2.70GHz stable with no errors at best.

Since you already have a good water-cooling system, you probably only need to spend about $180 for a pelt setup. ($90 for a Meanwell SP320-12, $50 for a Maze4-1, $20 for a pelt, $20 for insulation material – conformal coating, neoprene, dielectric grease.)

I personally went with the Maze4-1 because it’s about $75 cheaper than the Swiftech block, I couldn’t find any reviews or opinions that said the Swiftech is better, and I wanted to get my own 245W peltier instead of the 226W that comes with the Swiftech block. (I also think the Maze4-1 looks better, so that was nice.)

 

[datura3]

I just took off my pelt and it did run around -4 to 10C idle. I was able to super pi at 2.97 and now I can only super pi at 2.85. Of course it depends on the CPU, but I thought this info might be helpful. If I had to do it again, I would choose the mcw6000 series and make a custom mounting system out of 1/4inch copper. I think you can buy the 6002 for 35 bucks now.

 

[Pirate_Freder]

Revivalist-yes that is a stable clock but that is on my system that i have currently and am selling to build my new one (opteron 148 should be here today ).

also i think i am just going to go with the swiftech 5002 kit because i am not capable of making a cold plate. i found some good test result on this kit in a review here: http://www.systemcooling.com/mcw5002-64t-10.html
also, there cooling loop had half the flow and only two SINGLE 120mm fan heater cores, where as i will have two DUALS. they hit 11C at a 100w load. i will probabaly have about a 130w but now i am considering a new little trick*hehe*, i emailed thermal enterprises about performance of their peltiers and he said that in order to achieve the -60C on ht ecold side under load rather than how it is usualy only possible under 0 load you can cascade(stack) peltiers. if neccessary i can run another radiator. what do you guys think of this?

 

[datura3]

Revivalist-yes that is a stable clock but that is on my system that i have currently and am selling to build my new one (opteron 148 should be here today ).

also i think i am just going to go with the swiftech 5002 kit because i am not capable of making a cold plate. i found some good test result on this kit in a review here: http://www.systemcooling.com/mcw5002-64t-10.html
also, there cooling loop had half the flow and only two SINGLE 120mm fan heater cores, where as i will have two DUALS. they hit 11C at a 100w load. i will probabaly have about a 130w but now i am considering a new little trick*hehe*, i emailed thermal enterprises about performance of their peltiers and he said that in order to achieve the -60C on ht ecold side under load rather than how it is usualy only possible under 0 load you can cascade(stack) peltiers. if neccessary i can run another radiator. what do you guys think of this?

It's possible, but I hear that it doesn't perform that well. I really doubt that you will achieve -60C with a pelt cascade. That's a lot of heat to deal with. But I say, go for it. I'd like to see it done! Just be careful and you will need probably two to three radiators to deal with that kinda of heat. 130 +226 + a really large pelt (>380). You will need a large pelt that can handle the heat of the first pelt + processor.

Don't forget it will cost you a couple of hundred of dollars/year to run those 24/7. Fortunately, you will have to spend less on oil, since that will put out as much heat as most personal space heaters.

 

[Revivalist]

i emailed thermal enterprises about performance of their peltiers and he said that in order to achieve the -60C on ht ecold side under load rather than how it is usualy only possible under 0 load you can cascade(stack) peltiers. if neccessary i can run another radiator. what do you guys think of this?

I've read quite a bit of debate on this topic of stacking TECs. I don't know if it works in practice. . . .

But I think you might be heading toward the price of a phase change unit, which is gauranteed to keep you at negative temps under load. If you do two TECs, you would need

2 TECs (~$40)
2 power supplies for the 2 TECs (~$200)
Waterblock (~$50 or $120)
Another radiator (~$30)
Insulation (~$20)

Total: ~ $340-$410

 

[LabRat23]

@ LabRat - But the apogee doesn't come with mountings for a cold plate. It's not made for a pelt out of the box.

Does that mean you are agreeing with me?



Forget about stacking pelts. Its not possible on any modern cpu. If you stack pelts, the pelt on top has to take the heat of both the cpu and the bottom pelt with would be over 300w. There are no pelts with that capacity.


IMHO, pelts on a prescott is nonsence and as much as I have messed with pelts, I will never put one on a prescott. For what you end up paying including power costs, the bang for buck just doesn't compare to phase change.

 

[Pirate_Freder]

yeah i guess i would need about a 400w pelt , yeah i haven't seen any of those. hmm, well what are my options around phase? is there one that would be portable? cause i was going with water/tec for the portability. also how much? *winces*

 

[LabRat23]

Well reading your original post, I figure a single 226w pelt with the w/c system you already have is enough to do just what you want to do. I would go for it. Just remember that a pelt is not going to do anything else for you. If you want better than 0 to 8C with a pelt, forget it. Its easy to get caught up in trying to figure out what else you can do with a pelt but in the end you will find that the 0-8C range is just what a pelt will get you.

 

[Pirate_Freder]

you really think so? well what happened to revivalist? he only got to about oh what was it 22-30C somwhere around there. check out his thread on his setup and tell me where you think he went wrong. maybe the fact that he has 80cfm fans on a BIX3?
http://www.ocforums.com/showthread.php?t=425446