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Random/LFSR on P2

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  • evanhevanh Posts: 10,859
    ...
    Edit 2: The switch back to WSL 1 was easy (through PowerShell): 'wsl --set-version Ubuntu-20.04 1'... then re-launch my bash scripts, and done. Before the switch-back, all of my workloads had been quickly installed and recompiled 'native' under WSL 2 specifically for my (pair of) Xeon E5-2697 V2 processors (which I failed to do when I upgraded the CPUs), so it might be slightly faster than before.
    That's a relief for me too. I didn't know what to say.

    So the WSL 1 you're using now is both invoked and installed differently than before?

  • As far as I can tell, the installation of WSL 2 left WSL 1 intact. I could have simply switched my original Ubuntu from WSL 1 to 2 without re-installing Ubuntu, toolchain, apps, etc., but I didn't realize it at the time (i.e. trial by fire). Alternatively, I could have pinned one version of Ubuntu to WSL 1 and another to WSL 2 (which is what I will do on my laptop), but I would have to manage which is the default for launching bat files that call bash from Windows. Opening bash directly for either Ubuntu via shortcut is easy, though. However, I think that since switching back-and-forth the WSL version is also very easy, I'll keep just the one Ubuntu for now on that server for simplicity. I'll play with some of this on my small workstation (hopefully without getting too stressed).
  • xoroshironotxoroshironot Posts: 283
    edited 2021-02-10 03:25

    Evan, I'm picking up an AMD 3700X CPU/5700 XT GPU system tomorrow cheap (guy needs money for a new Xbox)... it should perform about 75% 70% of my 24C/48T server fully loaded, I guess.

  • evanhevanh Posts: 10,859
    Really? 33% of the cores. What about power consumption? You're just gonna run them all anyway aren't you. :)
  • xoroshironotxoroshironot Posts: 283
    edited 2021-02-13 17:41

    I have it up and running (water cooler pre-installed), but it came with Windows 10 Home, so will have to figure out how to get WSL working on it. Last I checked, it is possible, but not officially supported. It is supported on W10 Home.
    We will just have to see how it actually performs fully loaded... I was basing my performance assessment on the PassMark Cross-Platform rating of 43000 vs. 60000, but it might not be correct for my workloads on this CPU due to only 2 memory channels, etc.
    PassMark baseline: Here
    Edit: Win 10 Home does not support RDP. I installed a shim obtained from GitHub, and can remote out, but not remote in from another PC, as yet.
    Edit2: Looking for a spare Win 8 Pro license that I never used, which should be sufficient to bump Win 10 Home to Pro.

  • xoroshironotxoroshironot Posts: 283
    edited 2021-02-17 14:22

    @evanh said:
    Really? 33% of the cores. What about power consumption? You're just gonna run them all anyway aren't you. :)

    The preliminary performance figure for all-cores-loaded BigCrush on my AMD 3700X is 56% 58% (after letting threads normalize) of my dual Intel E5-2697 V2s.
    That is 16 threads vs. 48 threads, using DDR4 3000 RAM (vs 1866 on Intel), and the exact same Intel native executable.
    On a new AMD native compile and/or with DDR4 3600 and/or with a 3800 XT I might expect about 60% performance.
    It would take a 5800X to get the 70% performance figure I had guessed for the 3700X based on the PassMark cross-platform values.
    Therefore a 5900X should easily match the dual 2697 V2s, so 2x the performance per core/thread under full load.
    Knowing that will make it easier to calculate the performance of the next-gen Threadripper, hopefully out by late this year.

    I'm not worried about power consumption right now, but not much heat coming out of that case, unlike the dual Xeons which turn the PC into a space heater.

    Edit: The published PassMark dual-CPU cross-platform results are significantly lower than twice the single-CPU result. A simple equation that seems to better predict observed performance for all-cores-loaded BigCrush when comparing these two types of CPUs: '3700X cross-platform / (single-2697V2 cross-platform * 2 CPUs)', so 42854 / (35885 * 2) = 0.597.

  • evanhevanh Posts: 10,859

    Oh wow, the pricey Threadripper Pros have showed up locally. I wasn't really expecting to ever see one listed as a part. And I can even buy a motherboard for it too: https://www.pbtech.co.nz/product/CPUAMD03995WX/AMD-Ryzen-Threadripper-Pro-3995WX-64-Cores--128-Th https://www.pbtech.co.nz/product/MBDASU92011/ASUS-Pro-WS-WRX80E-SAGE-SE-WIFI

  • They should have had the TR Pro on track sooner, as I suspect the pending Zen 3 EPYC release next Monday may turn some heads.
    The expected IPC improvement is fairly well understood moving from Zen 2 to Zen 3, but the base/boost clocks also might see a significant increase, as well as other improvements, which early report suggest up to 40% better than Zen 2 EPYC under some workloads.
    If that is true, AMD would have to drive the price way up to avoid some potential competition with TR Pro.

  • @xoroshironot said:
    up to 40% better than Zen 2 EPYC under some workloads.

    Zen3 actually implements PDEP/PEXT BMI2 instructions in hardware (vs up to some hundred cycles of microcode), so if "some workloads" use those, it's an easy win.

  • evanhevanh Posts: 10,859

    @Wuerfel_21 said:

    @xoroshironot said:
    up to 40% better than Zen 2 EPYC under some workloads.

    Zen3 actually implements PDEP/PEXT BMI2 instructions in hardware (vs up to some hundred cycles of microcode), so if "some workloads" use those, it's an easy win.

    Ah, looking that up, I see that's part of AVX2. It's notable that all Zen processors are listed on paper as supporting AVX2 but Steam consistently excludes them from the AVX2 supported list.

  • xoroshironotxoroshironot Posts: 283
    edited 2021-03-29 20:39

    @Wuerfel_21 said:

    @xoroshironot said:
    up to 40% better than Zen 2 EPYC under some workloads.

    Zen3 actually implements PDEP/PEXT BMI2 instructions in hardware (vs up to some hundred cycles of microcode), so if "some workloads" use those, it's an easy win.

    I need to look into that more deeply, as I am planning to write a statistical analyzer for random numbers that will make extensive use of bit manipulation.
    It is based on an old drinking game where two people pick an integer from 1 to infinity, and the smaller value wins larger value buys the round, unless it is only 1 smaller larger, where the smaller value buys the next two rounds, and ties are discarded. A full analysis of the game shows that picking randomly from the integers 1-5 with the following frequency distribution is provably (1) the best strategy, with 2 and 4 picked 5/16 each, 3 picked 4/16, and 1 and 5 picked 1/16 each. There is a trivial way to use 4 random bits per person to create these ratios. My goal was to put this up against a Hamming weight dependency distribution analysis to see how it compares.

    1. From M. Gardner's 'Time Travel and Other Mathematical Bewilderments' (pg. 112): "For a proof of the strategy see "A Psychological Game," by N. S. Mendelsohn (American Mathematical Monthly 53, February 1946, pp. 86-88) and pages 212-215 of I. N. Herstein and I. Kaplansky's Matters Mathematical (Harper & Row, 1974)".

  • evanhevanh Posts: 10,859

    Crazy, that $9000 TR Pro I linked above is now listed as restocking and is the most popular of the Threadrippers sold there. Three other models in stock. It'd have to be someone like Weta Digital as a guess.

  • @evanh said:
    Crazy, that $9000 TR Pro I linked above is now listed as restocking and is the most popular of the Threadrippers sold there. Three other models in stock. It'd have to be someone like Weta Digital as a guess.

    That is crazy... the U.S. price for a 3995WX at Newegg is $5,488.99, and they are in stock. The way they are handing out money here, I could just about buy one, but then regret it 6-9 months down the road.

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