The 5 GHz, Six-Core Project: Core i7-980X Gets Chilly

Tom’s Hardware has been ringing the 5 GHz bell for years, yet those efforts have never yielded a practical daily-use solution. Today we take a look at how far off-the-shelf parts can take us with an ambitious 5 GHz, six-core overclocking project.

Our history with sub-ambient cooling goes back to the early days of this site, with our discussion of Kryotech’s first phase-change cooler in 1997 and our test of the improved version in 1999. Our 618 MHz Celeron quickly gave way to 800 MHz and 900 MHz Athlons, and even more cooling revisions pushed us past the GHz barrier less than a month later.

And then the competition showed up. Before Asetek became the purveyor of low-cost liquid cooling, its VapoChill phase-change system streamlined case and cooling components to a single box that supported processors from both AMD and Intel. By the time Prometeia threw its hat into the ring Kryotech had vanished and we had blown past 3 GHz. A few more improvements got us to 4.1 GHz, but reaching the next level would require a major improvement in either CPU technology or cooling capacity.

Liquid nitrogen cooling on the CPU and a phase-change cooler on the chipset finally allowed us to go beyond 5 GHz six years ago, an effort that inspired competitive overclockers the world over. Of course it wasn’t practical, because there were no practical 5 GHz solutions at that time. It wasn’t until Intel released CPUs on its 32 nm production process that “permanent” cooling solutions began to look viable for achieving these speeds. In fact, Chris Angelini was able to boot at 4.93 GHz using his Core i5-655K on air.

The technology was now in place to forgo temperamental liquid nitrogen cooling in our 5 GHz efforts, yet reaching this speed on a low-cost CPU that was already capable of running stably at 4.6 GHz with air cooling would have appeared trivial. The performance of a 5 GHz dual-core in a world of quad-cores would have been likewise laughable. We needed a properly high-profile, high-tech CPU to make this article worthwhile.

We knew we had a the perfect start for our project when Intel finally released its six-core, twelve-thread Core i7-980X Extreme Edition in March. A cooler with adequate capacity would still be required, and matched us up with the hardware

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  • algis87
    But can it play crysis 2 ... in 3D?
  • DaeM
    Our 5 GHz six-core still makes a great demonstration PC, but the same can be said of any of the liquid nitrogen-cooled systems that have already pushed this same processor model to 6 GHz.

    point made :P still a sweet demo on how to reacht 5 GHz and immediatly showing that it is not worth the effort at the moment...
  • andybird123
    what's funniest about this article is how succinctly it shows that most day to day applications don't get any kind of boost from hyperthreading

    I never understood the point of making one processor (or core) look like 2 to software when most software isn't heavily multi-threaded
  • Silmarunya
    andybird123what's funniest about this article is how succinctly it shows that most day to day applications don't get any kind of boost from hyperthreadingI never understood the point of making one processor (or core) look like 2 to software when most software isn't heavily multi-threaded

    The operative word here is 'most'. There is software that's heavily multi-threaded and that software is usually productivity software, usually heavy video/sound editing or something similar. People and companies buying these have a high technical knowledge and a high budget. There's a lot of money to be made in this market, probably as much as in the gaming market.

    So even though it isn't useful for most of us, it's a huge benefit for a minority with high demands and the of spending power to go alongside it.
  • Gonemad
    Like a well-tuned engine, each processor has an optimal working range. This one is exactly at this point, trading efficiency and low power consumption for little extra processing power, beyond the 3.xxGHz range.

    The previous processors (other mentioned tests) were below their respective thresholds, so it was even cost-effective to overclock them. Intel is really no fool.
  • LePhuronn
    Um guys, that's a Corsair PSU, not a Cooler Master one...
  • LePhuronn
    I'm content to push it to 4.2GHz on air and be done with it - shaving a couple of seconds off a render that's already 20 seconds isn't worth it to me.

    Still, nice to see a CPU given a kicking to see how far it'll go.
  • Tarnovsky
    I must admit I was surprised at the phase change cooler installation and issues with condensation.

    I run a modded Prometeia Mach1 which has been regassed and again reach the -40 temps although under load this is between -28C and -31C. Temps on many phase change coolers have often been a bit iffy.

    One of the original pros about the Prometeia system was the reconfigured mounting kit to reduce condensation, and use of seal string seals the unit totally.

    In short, without any further protection or heating element (one is installed) the system can run 24/7 without any sign of condensation.

    A good illustration of this is the fact that there is more impact on the board from ambient moisture and this can be seen when I remove any motherboards as the area around the LGA is 'mint'

    Certainly one of my colleagues has managed 5GHz and stable on this type of system with no issues.

    I myself use a QX9770 FYI
  • Tarnovsky
    ....continued from above

    Therefore I was surprised to see the condensation issues you had above and wanted to make a couple of observations.

    The foam used did not look either solid or dense enough and as such held air gaps and can transfer air, put you lips over a piece and blow, if air comes through it is wrong.

    Any form of wiring on these systems is a point of risk.

    Filling the LGA is going to stop you ever reselling your board, use of seal string at least allows you to clean the board off.

    regards Seal string, it is not necessary to pay some of the extortionate costs people charge for 'dedicated' seal string. Use a butyl sealant strip, which is all it is, but make sure it can go down to your temps, many can.

    Bear in mind Butyl sealant can also be used in liquid cooling to protect other components from leaks if necessary.

    One of the biggest area and challenges in phase change cooling is noise vs heat build up. Prebuilt coolers often struggle with higher ambient temps or make a lot of noise. As long as you keep the compressor cool and balance the radiator cooling you can have a suitably cool,system that quietly runs all day long.

    Took me about a month to get the cooling balanced on my current system

  • ksampanna
    That's a bit of an anticlimax.
  • gdilord
    Thanks for sharing your experience Tarnovsky.