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

Basic Overclocking

The Core i7-980X might be labeled as a 3.33 GHz model, but Intel's Turbo Boost technology automatically increases its clock rate to either 3.60 GHz or 3.47 GHz, depending on the number of cores being used. The screen shot below doesn’t show exactly 3,466 MHz because Gigabyte doesn’t set its base clock to a proper 133.33 MHz. With a default base clock of around 135 MHz, choosing manual settings to reach Intel’s intended 133.333 MHz base clock results in an actual clock speed of 133.0 MHz.

Notice that the highest temperature reached by our CPU at stock settings was measurable, exceeding the lowest-possible reading of its DTS (digital thermal sensor) at -12° Celsius. While we couldn’t track temperatures this cold in real time, the fact that they occasionally exceeded the minimum threshold tells us that the CPU core is much warmer than the -50° evaporator temperature reported by the Cooler Express status monitor.

I dropped my personal test voltage limit for Intel's 32 nm technology to 1.35V after a rash of blown processors swept Tom’s Hardware labs at settings as low as 1.375V. But those articles used air cooling, and processors do gain some voltage tolerance as temperatures are lowered. Today we use my air-cooled 1.35V limit as the starting point for our chilled-overclocking effort.

A modest 1.35V is already pushing our CPU temperature into positive numbers at full load, and we’re beginning to wonder whether surface imperfections on the evaporator will need to be addressed if we’re to maintain useful temperatures going forward. The CPU is coping admirably, reaching 4.46 GHz at 100% stability.

Our next step is 1.45 volts, which yields a stable 4.69 GHz at full load with Intel Hyper-Threading turning our six physical cores into twelve logical cores. Temperatures are still acceptable, climbing only a few degrees from our 1.35V results. Normal caution would have us stop here, but we’re committed to finding this processor’s limit or reaching 5 GHz, whichever comes first.

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    Top Comments
  • Crashman
    tacoslavei thought it would perform much better in games
    Check this out:
    http://www.tomshardware.com/reviews/core-i3-gaming,2588.html
    For the CPU to become the choking point, you need the GPU to be extremely powerful. Tom's Hardware formerly used unrealistic tests like Half Life 2 at 640x480 just to prove the CPU performance difference in games, but the fact that nobody used those settings eventually lead to the discontinuation of that testing method.
    16
  • dark bishop
    id like to see them try it on the phenom II x6
    15
  • zorky9
    Cooler Master’s reputable CMPSU-850HX

    Did you mean Corsair?
    13
  • Other Comments
  • Poisoner
    Pretty impressive. I wish Athlon II would over clock to 4ghz on air. :(
    10
  • zorky9
    Cooler Master’s reputable CMPSU-850HX

    Did you mean Corsair?
    13
  • tacoslave
    i thought it would perform much better in games
    -6
  • Crashman
    tacoslavei thought it would perform much better in games
    Check this out:
    http://www.tomshardware.com/reviews/core-i3-gaming,2588.html
    For the CPU to become the choking point, you need the GPU to be extremely powerful. Tom's Hardware formerly used unrealistic tests like Half Life 2 at 640x480 just to prove the CPU performance difference in games, but the fact that nobody used those settings eventually lead to the discontinuation of that testing method.
    16
  • noob2222
    tacoslavei thought it would perform much better in games

    There was a thread several months ago comparing the Intel Vs AMD platforms regarding the graphic card bottleneck. Suprising enough Intel cpus capped at a certain overclock where as AMD did not, eventually becoming faster FPS but required a much higher clock speed. It was determined that Intel has a limit on pcie bandwidth. Good luck finidng it, its probably over 6 months old.

    back to the arcitle, very interesting, and extremely expensive to even consider doing something like this.
    Quote:
    Finally there’s the expense. Our $900 cooler requires around 480W of power in addition to that consumed by the rest of the PC

    Add in the cost and time required to set this type of thing up as well as coating the MB ... lol, I don't even want to think about actually trying to go this extreme.

    Water is good for me, and if I want extreme, I will wait till winter and throw my radiator out the window while its freezing outside and pump antifreeze through it lol.
    7
  • liquidsnake718
    zorky9Cooler Master’s reputable CMPSU-850HXDid you mean Corsair?

    Nope coolmaster has a whole line of PSU's... they are decent and perhaps compareable to Corsair for albeit a slightly lower price point. But Oc'ing to 5.ghz and above is really crazy stuff here. I am actually happy with 3.0 and above already stock but damn, I dont think i would like to tax my system to 5.0 and above, regardless of cooling! It would cost more, but I do see the sport of it and commend those that take time to reach 5.0 and above figures with regular water cooled systems.
    -4
  • vinehoyle
    Amusing article. However some correcting is needed. The next to last paragraph states the cooler consumed 480W and the cpu consumes according to ur graphic 220w? My math says 700w JUST for the cooler and cpu. This calls in to question ur power bill figures. It's clearly much greater. I won't even talk about once u add things, though it would have been a good idea to calculate that figure too. Simply to show the madness of this project to ur power bill lol!
    5
  • Crashman
    vinehoyleAmusing article. However some correcting is needed. The next to last paragraph states the cooler consumed 480W and the cpu consumes according to ur graphic 220w? My math says 700w JUST for the cooler and cpu. This calls in to question ur power bill figures. It's clearly much greater. I won't even talk about once u add things, though it would have been a good idea to calculate that figure too. Simply to show the madness of this project to ur power bill lol!

    The article specifically states that the "added expense" figures are based on the 480W it takes to run the cooler. It assumes you're already planning to use the rest of the system at whatever speed you can get WITHOUT the cooler, and tells you how much MORE it costs to use the cooler. I think its fairly well explained, but feel free to point out any specific spot I missed, thanks!
    liquidsnake718Nope coolmaster has a whole line of PSU's...
    He's right, CMPSU-850HX is a Cosair model. Cooler Master does have some decent 850W power supplies though, I have one sitting in my liquid cooling bench station.
    3
  • dark bishop
    id like to see them try it on the phenom II x6
    15
  • Moshu78
    I'm sorry but once again, Tom's is testing CPU's while bottlenecking the Video. Can't you guys just use a simple rule like: When you test the CPU, use highest available video power (like Xfire of 5970), and when testing the GPU, use highest available CPU (980X). It's THAT simple. The 3D benchmarks are meaningless, waste of time AND money AND information. I predicted those graphs in the moment I saw you used a 5850 for the tests.
    7
  • Crashman
    Moshu78I'm sorry but once again, Tom's is testing CPU's while bottlenecking the Video. Can't you guys just use a simple rule like: When you test the CPU, use highest available video power (like Xfire of 5970)
    Yes, this is completely possible and highly desirable, please send two HD 5970 graphics cards immediately to the two remaining U.S. test labs that don't have them. And thanks for helping out!
    13
  • siman
    PoisonerPretty impressive. I wish Athlon II would over clock to 4ghz on air.


    Phenoms can reach that, why would you overclock an Athlon II anyway? This is a little pointless toms had to disable hyper-threading. Effectively killing off I'd say 45% of the CPUs juice. Im already running my Phenom II X6 @ 4.5GHz on water cooling. It runs everything vary well and with the money I saved on the CPU, I got 5850s in crossfire. All in a Micro ATX case...
    2
  • Crashman
    simanPhenoms can reach that, why would you overclock an Athlon II anyway? This is a little pointless toms had to disable hyper-threading. Effectively killing off I'd say 45% of the CPUs juice. Im already running my Phenom II X6 @ 4.5GHz on water cooling. It runs everything vary well and with the money I saved on the CPU, I got 5850s in crossfire. All in a Micro ATX case...
    Juice? It obviously saves enough power to drop the CPU temperature, but doesn't have a huge effect on average performance. Check out the benchmark difference between 4.7 GHz at 12-threads and 5.0 GHz with 6.
    0
  • Moshu78
    CrashmanYes, this is completely possible and highly desirable, please send two HD 5970 graphics cards immediately to the two remaining U.S. test labs that don't have them. And thanks for helping out!

    I'm sure Tom's have 2 x 5970 at their disposal and if they don't, just don't start to work if you don't have the proper tools. Cause the quality (results) will disapoint. Come on... I know there are Tom's fanboys on this website, which is understandable, but bottlenecking a stock 980X with a 5850 and then making graphs with how FPS don't change if you increase the frequence is just... sad.
    10
  • anamaniac
    I still run my i7 920 at stock just because I feel there's no reason for me to juice it up some.

    There's a nice German fellow working on a 5 stage cascade at xtremesystems, too bad its taken him over a year and a half without completion. Tom's should go ninja it from him when he finishes and bench a i7-980x and a Atom N270. :)

    Too many of hese 32nm melting below 1.4V (Highest I tried on air for my i7-920 was 1.55V).
    2
  • Crashman
    Moshu78I'm sure Tom's have 2 x 5970 at their disposal.
    I'm pretty certain they have a total of 3 to share between 4 labs, that Chris has two, Don has one, and Paul and Thomas have zero. I'm also pretty certain that Chris uses his two often enough that he hasn't been able to lend them to Thomas, and that Don actually lives in Canada :)
    7
  • haplo602
    simply cool :-)

    however the price/performance/convenience factor completely obliterates the result ... as was expected ...
    4
  • Tamz_msc
    So, the positive aspect of this article is that disabling HT reduced temps by 20 degrees.That's a HUGE decrease.Good job!:-)
    1
  • Reynod
    crashman always gets the best toys to play with.

    :)
    1
  • doomtomb
    Overclocking is OVERRATED and this article proves it.
    -6