For several years people have benched their computers, and still more join the game, and only a few part, thereby it gives you a hard time making your computer perform better then everyone else’s.
Most of you probably know about applications that are being used to benchmark your computers, applications like:
SuperPi
Hexus PiFast
3Dmark
Well, LN2 benching allows you that “little” extra too get on top of things :)
One year ago I would have said “processors keep making more and more heat, and thereby needs better cooling”, but that’s just not true, they make less heat than ever, due to new market strategies from the major CPU manufacturers, AMD & Intel. But even though the low W usage there’s still a lot to gain by using extreme cooling.
In case some of you wonder “what the heck is LN2”, now should be a proper time to answer that question, LN2 is Liquid Nitrogen, which is -196 deg Celsius, and works very good as coolant :)
What do you need for LN2 benching?
You’ll need a tube, solid or brazed, you’ll need LN2 of cause :) - And you will need some hardware that allows you to go seriously subzero, also, you need a truckload of money, ‘cause if you choose this path, you will definitely loose hardware now and then.
Where can you get LN2???
LN2 is not easy to get, I do not know how you will get it if your from Asia or the USA, but here, in Europe, we have a firm, Air Liquide, which produces LN2. It’s not like shopping in the local Ikea, you have to be a member in order to get the nitrogen, further in some country’s, you got to have your own dewar. (“can” for transport)
In Denmark, it’s possible to rent a dewar at Air Liquide, and quite cheap as well, 22 DKK (about 3.5$) a day.
How much will you need?
Of cause it depends on the amount of heat your hardware puts out, but it’s a darn shame to run dry, get 15 liters while your at it, you might only need 8-10 if it’s a low W CPU, but its not fun to run dry and being near a WR.
What is the price of LN2?
This question, I’m sad to announce I cannot help you with, in Denmark its 23DKK (3.8$) for one single liter… - My friend, Waus-Mod, from Holland, purchases his for 0.5 Euro a liter, which is WAY cheaper, so the price is not easy to tell.
How much is a tube?
The price of a tube varies a lot, a solid one will cost you 100-250$, while a brazed 50-100$.
Dewar:
http://img301.imageshack.us/img301/1...ede03329bx.jpg
Just next to the dewar I’ve put a A64 box, as most of you know the size of such a box,
this is a 25L dewar, and weights more than…. Well too much ;)
Tube
This is my tube, made by Minusgrader, a XS user from Sweden, its brazed, but works very well, sadly I don’t know the exact temperature, due to some bios complications.
http://img220.imageshack.us/img220/1210/botten6sg.jpg
http://img146.imageshack.us/img146/4416/klar19oa9ox.jpg
What potential does LN2 have as far as temps matter?
The temperature you will hit depends on tube, and CPU, I’ve tried two LN2 sessions so far, first was with a good old FX55 Clawhammer, it was very easy to get it to -120 deg, actually, I had to keep it warm in order to prevent coldbug in IMC, and that was a 1.85v 130nm CPU, the tube used was a 1.5” brazed Cu-Tube, made by a Danish fellow.
But I know from my dear mate, Waus-mod, that one of his tubes was -191 deg Celsius cold under load from his Dothan, a very decent temp considering LN2 being -196 deg.
The test
Config:
T2600ES QHJJ (step 4)
AOpen i975Xa-YDG
2*1GB Crucial Ballistix PC6400 4-4-4-12
Sapphire x1900 XTX
Preparation:
Before doing any tests, I mounted an IHS on the CPU, in order to make sure I don’t break the chip. Before mounting IHS I sanded it, in order to get perfect contact.
http://img174.imageshack.us/img174/8234/pict00079ob.jpg
http://img60.imageshack.us/img60/3118/pict00167gv.jpg
The board with insulation, armaflex tape, around socket
http://img73.imageshack.us/img73/5227/pict00175fk.jpg
Gear ready for some action, sadly I didn’t have time for making a PVC holding :(
http://img177.imageshack.us/img177/4257/pict00202qy.jpg
Anybody doubts this is some really cold stuff? Picture taken after I put down dewar safely, picked up my digicam and pressed the button!
http://img276.imageshack.us/img276/8812/pict00068ax.jpg
A little how not to do it, do NOT fill the tube, I just did it once to get a good picture,
It’ll only waste your LN2 a lot faster without gaining a thing.
http://img306.imageshack.us/img306/3835/pict00128cm.jpg
Funny how this coffee can gets all frosted up, but it sure did, also in the background, it’s quite easy to see that my hold down should have been in PVC, ice all over due to metal hold down.
Results
http://img58.imageshack.us/img58/4981/pict00171fp.jpg
First result, or actually, last one, but there are only two I took a picture of.
http://img143.imageshack.us/img143/3144/pict00077lu.jpg
SPI 32M
PiFast: 30.98s
SPI 1M: 17.375s
SPI 32M: 16m 27s
AM3: 134.159
01SE: 49.634
05: 15.193
Final thoughts
THIS WILL NOT WORK AS A 24/7 METHOD, DON’T EVEN CONSIDER IT.
I think of LN2 action as great fun, it’s the most extreme it gets. And its very different from normal benching, it’s a challenge.
M.Beier over’n out :)
PS: Feel free to download the entire picture collection!!
