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A Cray-1 supercomputer replica from 30 "obsolete" Mac Minis

arstechnica.com

62 points by pseudolus · 28 comments

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9 threads
TrevorFSmith

I know it's pedantic but this is a tribute or a re-envisioning but it's not a replica.

minimaxa

Just awesome; now they need SI to recreate Fortran in Rust to use Sketchpad?

I always wanted to build a mini CM-2 supercomputer with the red lights.

https://www.britannica.com/technology/supercomputer

amelius

Isn't the limit of supercomputing more about the data link speed than about the actual node compute speed?

  • robotnikman

    Thats what I thought as well. I think its possible to use the Thunderbolt 1 port for that, but it would still be rather slow.

    • amelius

      Well, you would need a crossbar switch to make that full NxN connection matrix. That's the hard part.

bitfilped

I don't get it, an actual Cray-1 getting refurbed would be much more exciting.

fortran77

Can it run Cray-1 software? The architecture is completely different. I coudn't get that from the article. It seems like a large cluster of Macs arranged superficially to look like a Cray-1.

ginko

>The Cray-1 team hopes to fill the currently empty second half of the tower through a crowdfunding campaign to secure 70–80 additional M4 Mac Minis. The goal: create a cluster capable of ranking on the TOP500 supercomputers list.

Is ~100 Mac Minis really all it takes to get into the TOP500 these days?

  • gs17

    I don't think so, the lowest from 2026 was still 2.66 PFlop/s, so they'd need thousands of Mac Minis. The M4s in the Minis aren't on a different level than the Xeons in those old clusters (outside of power consumption), even if we let the Macs use FP32.

  • shagie

    It would likely take a few more...

    but for some history fun: https://www.top500.org/lists/top500/2003/11/

    #3 on the list was "X" https://www.top500.org/system/173225/

    Virginia Tech, self made 2,200 core PowerPC 970 as 1100 G5 Macs with Rmax at 10,280.00 GFlops (this is 0.012 PFlops).

    ... and for some more history about the Cray vs modern computers... http://www.roylongbottom.org.uk/Cray%201%20Supercomputer%20P...

        “In 1978, the Cray 1 supercomputer cost $7 Million, weighed 10,500 pounds and had a 115 kilowatt power supply. It was, by far, the fastest computer in the world. The Raspberry Pi costs around $70 (CPU board, case, power supply, SD card), weighs a few ounces, uses a 5 watt power supply and is more than 4.5 times faster than the Cray 1.” This refers to official average geometric mean results.
    
    
    Back to TOP500... the 500th spot in June 2026: https://www.top500.org/lists/top500/list/2026/06/?page=5 is https://www.top500.org/system/179890/

    It debuted in 2020 at #130 with Max at 2.66 PFlops.

    A M4Pro mini today benches at 8.520 TFlops https://www.check-mac.com/en/product_benchmark-apple_mac_min...

    From the article, the minis they are using:

        ... the developers can orchestrate the 64 active processing cores into a combined 1.3 teraflops of performance in their most recent tests.
    
    That's a rather nice number... it will need about 2000x of the current systems to match the current 500th spot.

    ... however it would only take about 300 Mac M4Pro minis to get to the 500th spot today.

  • mat_epice

    Pretty sure not, especially since it requires 64-bit floating-point, so the GPU cores don't help. #500 right now is 2PF. One Mac won't do anywhere near 20 TF. Google tells me you can get 350GF of DP from one 10-core M4, so you might need 10,000 to get there. Then there's the network...

mrlonglong

They could rent out all that compute to subsidy the museum running costs.

  • gs17

    Rather than rent it out (maybe some people would pay a few bucks a year for novelty web/mail hosting, but it's both too much and too little for most use cases, running the program of renting it probably eats up a lot of the revenue), maybe they could give compute time to universities for free, with the requirement that they provide some sort of display for museum visitors? There's probably some people with Monte Carlo simulations that could benefit from a lot of cores (if they get the M4 upgrade) while being on a student budget of $0. And if no one has requested it, they could run some BOINC project that has a nice visualization.

  • eric__cartman

    I doubt distributed compute in a bunch of old i7s is worth much once you factor in the electricity cost

  • bigyabai

    The RAM shortage is bad, but not that bad (yet).

    • mrlonglong

      You think it's bad now?

      New 48GB DDR5 ECC UDIMM chips are retailing for £2.5K each in the UK.

ck2

imagine showing even the first iphone to a Cray engineer in 1976

they'd lose their minds lol

(Cray-1 was 160 megaflops, smartphones are teraflops)

  • mat_epice

    The Cray-1 was measured on 64-bit FLOPS, so you would have to do apples-to-apples (heh). A modern iPhone can do 300 GF of 64-bit, so only 2000x.

    The iPhone 4 was probably the first that could beat a Cray-1, and it was by a narrow margin. However, that was only a 32-bit chip. The next year iPhones went 64-bit, and it was all over.

    • gcanyon

      We live in an amazing era, where the limit to what we can do is (almost?) more what we can imagine to do than what we are actually able to do.

      • brewtide

        I phrase this to my kids in a different way, but same exact sentiment: The only limit these days is a modest amount of resources and the ideas in your head.

        ie. Feature film? Sure. Music album, sure. Your own electronics project designed at the kitchen table, ordered from china, housings printed on the 3d printer -- all from the table.

        It is an absolutely astoundingly low bar of entry these days to almost anything you'd like to create or build.

      • dmd

        oh, but a man's reach should exceed his grasp. Or what is a heaven for?

    • ciupicri

      There is also the issue of cooling. The iPhone will need extra cooling in order to function at full speed for more than a few minutes.

    • ck2

      I genuinely love r/TheyDidTheMath corrections, thank you!

      (now calculate it in iphone charger plug computing power heh > lunar lander)

  • bigyabai

    I don't think they would be that surprised. Look at the inside of the Cray-1: https://thumbs.dreamstime.com/z/inside-red-yellow-cray-super...

    If you were an engineer working on this machine, it was visually clear to you that the modularity took up the majority of the space. The ICs themselves were already pretty dense.

latchkey

The picture with all the cables everywhere... ugh that sets off my OCD.

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