Feeds

AMD spills secret to World Record clock speed

A little liquid helium goes a long way

The essential guide to IT transformation

On August 31, a team of AMD-sponsored overclockers cranked a Bulldozer-based AMD FX processor up to an unearthly 8.429GHz, setting a new world record. This week, The Reg sat down with the leader of that processor-torturing team to find out exactly how they did it.

"This is an extreme technology sport," Simon Solotko, AMD's senior manager of social media, told us. When we asked if social media wasn't a bit of a stretch from overclocking, he said he first got into social media through overclocking connections. Then he grinned. "I also do a number of our more extreme activities."

Any extreme sport requires its own specialized equipment, Solotko said. In the case of extreme overclocking, two of the most important tools are liquid nitrogen and liquid helium.

"It's really cold stuff," Solotko said of liquid helium. How cold is "really cold"? Well, liquid helium boils at -268.93°C (4.22 K). Liquid nitrogen, on the other hand, boils at a comparatively toasty -195.79°C (77.36 K). Solotko referred to liquid helium as "the coldest readily available stuff you can get for cooling."

Liquid nitrogen is all well and good, he told us, but liquid helium can get you close to absolute zero.

When overclocking AMD's Phenom II – an earlier processor – Soltko discovered that it could be operated at extremely cold temperatures. That isn't true of many if not most electronic circuits, which often fail under extreme cold.

Cold can affect timing, Solotko says, and it can also affect power circuits. If you get a voltage regulator too cold, for example, it will stop switching and it will "fry everything." So one of the precautions that Solotko and his team took was to ensure that their AMD FX was well-isolated from other motherboard components.

Extreme cold doesn't merely prevent a fast-cranking processor from overheating, he reminded us. Extreme cold also helps the conductivity of silicon.

To cool the test processor down to as close to absolute zero as possible, Solotko told us, his team first cools the processor with liquid nitrogen. Then they let the liquid nitrogen evaporate so it doesn't turn to ice. And then they use the liquid helium.

Liquid nitrogen turns to ice at -209.86°C (63.17 K), by the way, and liquid helium is about 60°C colder than that.

Once the liquid nitrogen has safely evaporated away from the cooling assembly on top of the processor, "Then we hit it with liquid helium, and we take the temperature further down still."

When we asked him exactly how cold he and his team were able to get their test chip, Solotko said he didn't know. The problem, he told us, is there isn't a thermometer that's accurate to those temperatures. The thermal probes that the team used read around -230°C, Solotko said, but this can't be trusted. "We don't actually know what that means. Our guess is that we're somewhere in the vicinity of 10 degrees north of 0 K."

Another reason that the true temperature of the silicon remains a mystery is that there are temperature gradients between those ludicrously fast-switching transistors and the temperature probes. Solotko cited as examples the first copper layer over the silicon, which he called the "metal lid", and the bottom of the liquid nitrogen- and helium- containing copper "pot".

Boost IT visibility and business value

Next page: Miraculous pot

More from The Register

next story
So, Apple won't sell cheap kit? Prepare the iOS garden wall WRECKING BALL
It can throw the low cost race if it looks to the cloud
Apple's iWatch? They cannae do it ... they don't have the POWER
Analyst predicts fanbois will have to wait until next year
AMD unveils 'single purpose' graphics card for PC gamers and NO ONE else
Chip maker claims the Radeon R9 285 is 'best in its class'
Barnes & Noble: Swallow a Samsung Nook tablet, please ... pretty please
Novelslab finally on sale with ($199 - $20) price tag
Apple to build WORLD'S BIGGEST iStore in Dubai
It's not the size of your shiny-shiny...
Just in case? Unverified 'supersize me' iPhone 6 pics in sneak leak peek
Is bigger necessarily better for the fruity firm's flagship phone?
Steve Jobs had BETTER BALLS than Atari, says Apple mouse designer
Xerox? Pff, not even in the same league as His Jobsiness
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
5 things you didn’t know about cloud backup
IT departments are embracing cloud backup, but there’s a lot you need to know before choosing a service provider. Learn all the critical things you need to know.
Why and how to choose the right cloud vendor
The benefits of cloud-based storage in your processes. Eliminate onsite, disk-based backup and archiving in favor of cloud-based data protection.
Top 8 considerations to enable and simplify mobility
In this whitepaper learn how to successfully add mobile capabilities simply and cost effectively.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?