To go below zero....

[[KoG]^weaZel]

Lately I have been doing alot of reading about people making they own cascade phase-change coolers. This brings me to want to do the same. the question is: should I? If I was doing benchmark runs all the time on different systems I think I would take this project on. I think that I need to finish my current project and then maybe later on I will build one of these monsters. But it does sound good to get a cpu down to -40 to -100c! After all I am sure I would be able to take the WR from Fugger for the Pentium Extreme Edition 840. His record stands at 4.9ghz. So far I have been able to run 4.4ghz on water. I guess time will tell.
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I tweaked and it tweaked back! So I Tweaked some more!

"Barney is like the Michael Jackson of PBS." - James Tybeerious

[Google]

[PhRoZeN_X_]

Go for it bro. It would be some sweet if you took a WR. Tweak news and weaZel #1 sweeeet !!!!!

[fussnfeathers]

I think they'd be more for bragging rights, than for any true performance gain....and in fact, there is a law of diminishing returns when it comes to CPU temps. For example, to get a 500mhz OC, you have to cool the CPU down to 20c or so (on average), which is only a 20-25c drop. Cooling the proc down to 0c (another 20c) might only net you another 100-200mhz.

Of course, this isn't counting some engineering samples, the very rare monster OC, or procs that are designed for sub-zero temps.

Also bear in mind that electricity does require a certain amount of heat to work properly. Cooling the CPU die to sub-zero temps sounds impressive, but it can actually hurt your performance more than help.

This is based on averages, of course, not set in stone. Obviously some guys have gotten massive OC's (1.7ghz on Fugger's part), but that's the exception, not the rule.

If ya gots the dough, go for it, the experience is worth it.......and when you're done proving it works, you can send me one of the PC setups.
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Big enough to scare you

[meobius]

if you need a vapochill unit, i have a spare one i was thinking of selling.
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If time is of the essence,
than why is it that we waste,
that which holds such great importance,
spent without a trace.

[fussnfeathers]

LMAO

I'm not in the market anytime soon, I have to find a job first. Not to mention the cost of electricity here.......I'll be sticking with air cooling for awhile.

Although.......if I took cold showers, and cooked dinner on the grill every night, I could cut the electric bill.......
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Big enough to scare you

[FreeTheRock [banned]]

i know a guy who got the FX-57 to 3.9 with ln2 i think is what its called and he oced the 7800GTX to 600+ core.

[[KoG]^weaZel]

right now the WR is a little over 4.0ghz on the FX-57.

And with temps in the neighborhood of -100c they have gotten Intel chips to 7ghz and broke 19 seconds for SuperPi at 1m. So there are great returns when you drop the temp that much.

Fugger has gotten a single core P4 to 7ghz, but that was just in bios with a prototype motherboard from DFI. That was with a 925X chipset. The new 955 chipset overclocks much better. Not to mention DDR2 modules have gotten alot better lately.

Maybe I will start off with a Vaporchill unit. Meobius, you say you have a spare? how much and what about shipping? PM me and maybe we can do some business.
_________________
I tweaked and it tweaked back! So I Tweaked some more!

"Barney is like the Michael Jackson of PBS." - James Tybeerious

[fussnfeathers]

Like I said, those are the exceptions, not the rule. And it still follows.....at -100c to get a 3.2ghz OC (assuming a 3.8ghz chip stock), a bit of math.........

If it were a linear progression, let's just say a 500mhz OC for a 20c drop (just a random figure, pretty close to what most people get with a stock WC setup) from, say, 40c idle temps.......a 140c drop in temps would net you an OC of between 3.5 and 4ghz. Unfortunately, it's not linear. You get the best OC's within a smallish range (usually between 0c and 20c, from everything I've read), up to an average of a 1.2-1.5hghz possible OC at 0c. That's close to half of the total OC you're mentioning of approx. 3.2ghz. So the remaining temp drop, at around three times the temp difference, only nets you as much as the first 20-40c drop. I'd be willing to bet that in the last 20c drop from -80c to -100c might only net you a 50mhz bump, just to round out the figure. That's 1/100th or less of the OC from the original drop to 0c.

It'd be interesting to see a few comparisons graphed out, I'm pretty sure I'm right in my thinking, but it would be nice to see it on paper, so to speak.
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Big enough to scare you

[[KoG]^weaZel]

ok I have already found that it should be possible to get a 1.1 to 1.2 ghz overclock on my dualcore with watercooling. So with phase should be able get another 700 to 800 mhz easy. Even at the 4.3 and 4.4 ghz I am still at stock voltage. I still need to get windows loaded and then I will start on the CPu burn-in runs. I am going to try and get this cpu to run on the lowest possible vCore possible.

If you want to do a little reading on what possible with some phase change, dry ice, and LN2. Check out this section, especially the "world record database"
http://www.xtremesystems.org/forums/forumdisplay.php?f=56
_________________
I tweaked and it tweaked back! So I Tweaked some more!

"Barney is like the Michael Jackson of PBS." - James Tybeerious

[(DJ PhiLO)]

Dont know if you guys have seen this.

http://www.tomshardware.com/cpu/20031230/5ghz-03.html

[[KoG]^weaZel]

[quote="(DJ PhiLO)"]Dont know if you guys have seen this.



yeah old news.
Team Japan holds the WR right now at a little over 7.2ghz benchable under LN2 using a P4 670 on an Asus P5wd2
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I tweaked and it tweaked back! So I Tweaked some more!

"Barney is like the Michael Jackson of PBS." - James Tybeerious