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Overclocker Pushes Intel Core i7-7700K Past 7GHz Using Liquid Nitrogen (hothardware.com)

Posted by BeauHD on from the if-you-can't-stand-the-heat-get-out-of-the-kitchen dept.

MojoKid writes from a report via HotHardware: If you've had any doubts of Intel's upcoming Kaby Lake processor's capabilities with respect to overclocking, don't fret. It's looking like even the most dedicated overclockers are going to have a blast with this series. Someone recently got a hold of an Intel Core i7-7700K chip and decided to take it for an overclocking spin. Interestingly, the motherboard used is not one of the upcoming series designed for Kaby Lake, but the chip was instead overclocked on a Z170 motherboard from ASRock (Z170M OC Formula). That bodes well for those planning to snag a Kaby Lake CPU and would rather not have to upgrade their motherboard as well. With liquid nitrogen cooling the processor, this particular chip peaked at just over 7GHz, which helped deliver a SuperPi 32M time of 4m 20s, and a wPrime 1024M time of 1m 33s. It's encouraging to see the chip breaking this clock speed, even with extreme methods, since it's a potential relative indicator of how much headroom will be available for overclocking with more standard cooling solutions.

7 of 139 comments (clear)

  1. Most depressing thing I've read all week by phantomfive · · Score: 5, Interesting

    If I recall correctly, the first time someone got over 8 Ghz was back in ~2004, over a decade ago. I know clock speed isn't everything, but parallelism will only get you so far. I really hope before we get to 5nm chips, we can get some 20 Ghz clock speeds. The amount of work you'll be able to do on a single thread will be amazing.

    --
    "First they came for the slanderers and i said nothing."
    1. Re:Most depressing thing I've read all week by Anonymous Coward · · Score: 4, Informative

      If I recall correctly, the first time someone got over 8 Ghz was back in ~2004, over a decade ago. I know clock speed isn't everything, but parallelism will only get you so far. I really hope before we get to 5nm chips, we can get some 20 Ghz clock speeds. The amount of work you'll be able to do on a single thread will be amazing.

      The only thing inherently inefficient about parallel computing is the inefficiency created by the overhead required to keep the software consistent and coherent. The real problem with multi-core computing is very little software is written in such a way that it can run on multiple CPUs. Hell, my professors were saying that in college 15 years ago, and it's still true today.

    2. Re:Most depressing thing I've read all week by phantomfive · · Score: 5, Interesting

      The only thing inherently inefficient about parallel computing

      Not all things are parallelizable. Sometimes you must wait for part A to finish before part B can begin. The obvious example is anything requiring user input (like games). Another example is databases.....when they wan to maintain ACID, they must do some things sequentially (which is unfortunately a huge bottleneck). See also, Amdahl's law.

      --
      "First they came for the slanderers and i said nothing."
    3. Re:Most depressing thing I've read all week by phantomfive · · Score: 3, Insightful

      Not everyone is putting their crap on AWS. Some of us still like our crap local. Not everything is 'in the cloud' or even 'web based.'

      --
      "First they came for the slanderers and i said nothing."
    4. Re:Most depressing thing I've read all week by Ramze · · Score: 4, Interesting

      Intel gave up on increasing clock speeds way back when they hit 4Ghz. They hit a wall, and they're done, so I wouldn't expect them to revisit it. That's when they went to multi-core. Every computer does better with dual core over single core. Most do better with quad core than dual core. (because even if a single program isn't compiled for multi-core, different programs can be assigned different cores). With VR tech and GPUs added to the cores, multi-core is likely going to continue to be the area of development for some time. As always, expect new physics and graphics extensions as well as codecs.

      Multi-core means managing the power and speed of each core individually and allowing some to power down while ramping up one or two to keep the thermal and power envelopes within tolerances. The biggest metric for Intel is performance per Watt -- as data centers are concerned about power usage for the machines and the air conditioning systems.

      I don't think there is enough of a market for enthusiasts that want 20 Ghz clock speeds for Intel to bother even doing the research for new materials to pull that off... assuming it's even possible without extreme cooling.

    5. Re:Most depressing thing I've read all week by Ramze · · Score: 5, Insightful

      This is true, but the CPU isn't the bottleneck for your examples. For user input (especially games), the user is the bottleneck. Games largely benefit from parallelization for rendering graphics. The logic isn't the bottleneck, and the latency for the response of user input is imperceptible to the human. For most instances, the RAM and CPU are waiting on the human and already have everything loaded to respond to the human. If a human's choice requires the loading of a different zone, the game could even predict which zone would load and pre-load a zone without human input, but dump it if the input wasn't what was predicted. Still, it's the I/O for the disk that's the bottleneck, not the CPU.

      As for databases, the biggest bottleneck is the storage medium. Depending on the database and how it's divided, one can even run many tasks on the same database simultaneously so long as the tables don't interact. Ramping up the CPU speed does little to nothing if the I/O to the storage medium of the database is slow b/c the db won't unlock the region of the database for the next transaction until the last transaction is written at least to a buffer if not the final storage medium.

      For that example, the best way to improve DB processing is to add RAM, add cache, and increase the clock speed of both.... if possible, even let entire tables if not the full database to exist in RAM and only write to disk periodically as a save-state. Even DDR4 2400 RAM only operates around 1.2 Ghz, though with access on rising and falling edge, it's effectively 2.4 ghz. What is your 20 Ghz CPU going to do with 10 cycles between every read and write to RAM ? Current Intel CPUs have a 4 stage pipeline. Even with a sizable cache at a higher speed, it's going to choke on the RAM latency... especially for large sequential database transactions. RAM is already hot enough to fry eggs on, so it'll be until the next RAM replacement tech comes out before we see some real boosts there. Maybe in a year or two.

      I'm curious what exactly you'd like to run at 20 Ghz through the general purpose CPU registers that can't be done better/faster with extensions using specialized hardware. For instance, x265 HEVC video playback can really heat up a CPU to nearly 100% usage, but if it has x265 decoding hardware, the CPU barely breaks 1% playing the same video on a similar CPU architecture and speed. Seems if you have a single thread that you need to have repetitively run at very high speeds, you'd rather have a FPGA or some other hardware to accommodate whatever you're trying to do rather than a general purpose cpu.

  2. Meanwhile, the bus speed... by inflex · · Score: 4, Informative

    ... lumbers along at 100MHz still.

    Time we started working on that side of the hardware some more.