Hacker News Reader

Comment by walrus01 | Hacker News Reader

Cooling: "Liquid Nitrogen" reminds me of the amazing day when somebody first overclocked a slot based AMD Athlon to 1.0 GHz using a custom refrigerant loop system.

View on HN

Cooling with Liquid nitrogen is in some ways simpler than a refrigerator cycle since it’s completely impractical to compress & recondense it. A cryogenic cooling system usually just vents the gas into the room, it may just be a little well around the part which gets filled with ln2 from a dewar.

Indeed so, I remember seeing people do temporary "overclocking world records" with things like 900 MHz Pentium 3s, and Athlons, around twenty years ago, bare motherboard on an open table with liquid nitrogen dewar mounted to the CPU socket. Guys pouring more nitrogen into the thing as it evaporates and they run benchmarks. I guess the procedure for that probably hasn't changed very much, since it's a very ephemeral and temporary process.

Youtube channels like Gamer's Nexus are still out there doing this exact kinda thing. I'm still as fascinated by it now as I was back then.

Related from a little while ago: https://news.ycombinator.com/item?id=24280218

Do you need some form of sonicator to keep bubbles from sticking?

Not in practice. I deal with LN2 cooled optical detectors, and the bubbles clear themselves out pretty quickly. Sometimes folks add a little bit of sand to help the bubbles nucleate.

> A cryogenic cooling system usually just vents the gas into the room, it may just be a little well around the part which gets filled with ln2 from a dewar.

It depends on the scale, and whether the cooling is only required for a short while.

Large scale cryogenics (such as at CERN, an LNG tanker etc) will recompress the vapor as it forms.

If so, the loop basically IS as refrigerator, just a much bigger, higher performing unit.

For an extreme example, see: https://home.cern/science/engineering/cryogenics-low-tempera...

True, I should have qualified the phrase impractical by stating at this scale. it’s an industrial scale process that because of the pressures and temperatures involved isn’t practical to use for anyone who isn’t permanently installing it at significant capital outlay - which, wouldn’t be practical for cooling any cpu other than maybe a supercomputer.

Man what a throwback, memories I forgot I had. I was all about upgrading my K6-2 450 to a 550, but was equally fun to cheer on AMD's Slot A chips that had begun to erase Intel's dominance at the time.

The peak of tech excitement in my entire life was when a friend brought a copy of Computer Shopper to school, and the cover proclaimed a new 90Mhz 486!! No other tech ever blew my mind like that again.

Likewise - I remember someone walking into art class at school with a computer magazine featuring at 100mhz 486 DX4 on the cover. Triple figures!

I have to wonder if computer parts are less exciting now because of the lack of generational improvement or the fact that I'm an old fart that can't spend a bunch of time geeking out over the next generation.

I really followed computer evolution during the GHz wars. Watching a CPU go from 300Mhz being fast to 2GHz being fast was amazing. Then watching as AMD pulled 1.8GHz parts and kicked the pants off of Intel's 2.5GHz parts was equally incredible to young me.

Now I see generation to generation pushing 5->10% improvements and mostly go "meh".

Do you remember being able to run DooM and Winamp at the same time!?

Upgrading from 450 to 550? I once had an AMD Duron 650, which I overclocked very late in its life to 850MHz simply by increasing the FSB from 100MHz to 133Mhz (or so), no extra cooling or anything.

Yeah maybe today 100MHz difference might not seem like much, but it's a >20% increase which is nothing to sneeze at! I did a similar one (K6-2 366MHz to K6-2 550MHz).

Those lower-clocked Durons you mentioned were fantastic value though - I remember buying a 700 MHz part and running it at 900 MHz (after using a pencil to short those traces on the chip that let you manipulate the clock multiplier)

The biggest overclocking story of all time was when people discovered that (many/most?) 300Mhz Celerons where intentionally mislabeled 450Mhz ones, because apparently the yields where such that they couldn't not make mostly 450Mhz ones.

Those werent miss-labeled, as there were never 450MHz Celerons. This overclockability was due to excellent 0.25um lithography process Intel was wielding at the time. Every Intel CPU had same MHz ceiling, even older laptop 200MHz Pentium 1 MMX Tillamook CPUs overclocked to over 400MHz https://www.youtube.com/watch?v=fqB4yCssUCM. This was also one of the reasons for Intel to start fighting with overclockers by locking multipliers.

Thanks for the correction, I remember indeed it was as you said, simply that they were capable of much higher frequencies.

I didn't know that it was the case with other models, I guess I was mainly eyeing Celerons at that time because they were so cheap.

Also reminds me of this old video (early 2000s) that shows what happens when you remove the heatsink. This is what cemented that image in my head of “AMD=cheap knockoff” that AMD reversed only 2-3 years ago (and now I am trying to source an EPYC Milan!).

https://www.youtube.com/watch?v=YYQSHXNFvUk

This exact video had a big impact on my impressions of those companies as well, it's pretty amazing how long those views last.

What you probably never saw was the non-retraction retraction Tomshardware had to publish later, and buried so deep even archive.org doesnt have access anymore. Yes, they manually excluded the link from wayback machine :o

Here is the whole story: https://www.tomshardware.com/reviews/hot-spot,365-4.html somehow still accessible under its original 2001 link unlike most of their old material, wonder why :)

>"AMD did not bless the Thunderbird core with ANY thermal protection whatsoever."

In reality AMD socket certification required thermal cutout, same as Intel for Pentium 3. AMD processors do include thermal diode just like Intel ones.

>"Intel's older processor is also equipped with a thermal diode and a thermal monitoring unit"

is a lie. Pentium 3 thermal throttling is performed by the Bios just like in Athlon case. Serendipitously tomshardware picked broken Siemens motherboard for AMD system as recommended by Intel, imagine that.

They published a non-retraction catching Siemens in a lie and showing proper AMD setup safely shutting down. Of course you cant read it because its buried down, excluded from wayback machine and deadlinked http://www.tomshardware.com/column/01q4/011029/index.html

The Kryotech SuperG!

http://www.thg.ru/cpu/19991115/print.html

That was mindblasting for me at the time and remember I dreamed of buying one.

Now I have a multi-ghz Ryzen 270p.. not even the latest and gratest and take it for granted.

Those were the days...

It's unfortunate that the images seem to be gone now, because I remember it being quite a feat of engineering for its era.

It looks like there's some shots of it here: https://www.anandtech.com/show/432/2

LN2 is pretty standard for extreme overclocking. Requires a lot of preparation due to water condensation and some blow torch heating for the system to start up as it can fail to boot entirely.

It's fairly simple and most pundits can do it at home if they so desire.

Reply on news.ycombinator.com