View Full Version : OC difference between low end phase change and cascade
l3ored
10-27-2005, 03:05 PM
If one already had a single stage direct die system, at say -30C, with their processor fully overclocked, how much higher could they expect to push it with a cascade around -100C?
RussC
10-27-2005, 03:27 PM
Thats almost impossible to answer as OC is a one off proposition at best ie each CPU will respond differently to temp differences. We could guess, but that would be dis-ingenuous. It may not OC higher with the temp change lower :eek:
RussC
sin0822
10-27-2005, 03:39 PM
low end phase change is liek -15c btw, and some people say that you gain 3% for every 10c below ambient, its all BS there is no way of determineing.
jinu117
10-27-2005, 07:08 PM
There are some in forum who has both and maybe able to tell you on select few candidates they played with.
l3ored
10-27-2005, 07:09 PM
anyone mind discussing theory? as i understand it, your max oc is just below the point where energy leaks between transistors (or something like that) and ultimately causes errors and system instability. having your processor cold reduces the ammount of leakage, while allowing you to push more volts through (because you're not going to fry anything) and getting a higher overclock, right? it seems to me that having a temp at or below room temperature is superb (i'm talking under load and with extra voltage) and below 0, heat is such a small factor of system instability, that it shouldnt matter whether you're -15 or -100. the lower temp probably helps in cooling parts around the processor more than helping stability in the cpu itself. please correct me because i'm sure i'm wrong just about everywhere.
l3ored
10-27-2005, 07:10 PM
There are some in forum who has both and maybe able to tell you on select few candidates they played with.
yea, i'd like that *hint hint wink wink*
eshbach
10-27-2005, 08:10 PM
my 830 did 4.9ghz with single stage and 5.4ghz with cascade.
570 did 5.1ghz with single stage and 6.0ghz with cascade.
haven't had an AMD recently that worked at all on cascade.
l3ored
10-27-2005, 08:25 PM
my 830 did 4.9ghz with single stage and 5.4ghz with cascade.
570 did 5.1ghz with single stage and 6.0ghz with cascade.
haven't had an AMD recently that worked at all on cascade.
ok, big difference then. can anyone explain why?
Well, a few things. In CMOS, electron mobility increases as temperature decreases. Also, thermal noise is reduced. Leakage current from subthreshold transistor operation is also reduced. I'm sure there are other good reasons more CPU specific as well.
It seems chips with cold "bugs" have components which simply don't operate properly at extremely cold temperatures way out of their original design specs.
jinu117
10-27-2005, 10:44 PM
Not only what weee said, the cold bug might have something to do with CPU design inside as well. When winchester first came out, I had major cold bug issues with them on single stage. I've tried many different MOBOs, CPUs and came to conclusion it was combination of CPU and mobo too. I remember Asus giving you about 10c margin more while MSI and Gigabyte didn't play as nice for same CPU. Also, variance among CPU was great. Some will boot -25c, some will boot -40c, some will boot -45c based on MSI back than.
Anyways back to topic... Bored. Do you have single stage? Cascade sound fun but requires bit of disciplene.
l3ored
10-27-2005, 10:59 PM
no, at the moment i got nothing but curiosity. i want to get into phase change, but at the moment i dont think i have the time or money (college student), i'm just gathering information for later when it's a possibility.
jinu117
10-27-2005, 11:49 PM
no, at the moment i got nothing but curiosity. i want to get into phase change, but at the moment i dont think i have the time or money (college student), i'm just gathering information for later when it's a possibility.
Good way to go... :) only took me 2 years of keep reading before I got my first unit. (went through air->water->peltier->phase and a lot of back and forth in between). Everytime though, more you read, more efficient you are at getting to where you want to and less mistake on purchases which can add up quickly. Save money and pain by studying :) Cascade till today is bench only kind of system really. It might change once there comes controllers that can monitor all kind of situations but power draw alone would make it unsuitable really for anything other than benching. There are plenty of, actually most of single stages are that can run 24x7 (daily rig). Which actually do quite well if you are not going for world record on benching too :)
l3ored
10-28-2005, 01:01 AM
i'd like to get a 24/7 rig up and fit it all in one, compact case, because i'm a hardcore gamer and go to lan parties.