• 0 Posts
  • 22 Comments
Joined 1 year ago
Cake day: June 25th, 2023
  • qupada@kbin.socialtoSelfhosted@lemmy.world•EPYC for Desktop: It's finally here! (and cheap too)
    3·
    6 months ago

    Probably best to look at it as a competitor to a Xeon D system, rather than any full-size server.

    We use a few of the Dell XR4000 at work (https://www.dell.com/en-us/shop/ipovw/poweredge-xr4510c), as they’re small, low power, and able to be mounted in a 2-post comms rack.

    Our CPU of choice there is the Xeon D-2776NT (https://www.intel.com/content/www/us/en/products/sku/226239/intel-xeon-d2776nt-processor-25m-cache-up-to-3-20-ghz/specifications.html), which features 16 cores @ 2.1GHz, 32 PCIe 4.0 lanes, and is rated 117W.

    The ostensibly top of this range 4584PX, also with 16 cores but at double the clock speed, 28 PCIe 5.0 lanes, and 120W seems like it would be a perfectly fine drop-in replacement for that.

    (I will note there is one significant difference that the Xeon does come with a built-in NIC; in this case the 4-port 25Gb “E823-C”, saving you space and PCIe lanes in your system)

    As more PCIe 5.0 expansion options land, I’d expect the need for large quantities of PCIe to diminish somewhat. A 100Gb NIC would only require a x4 port, and even a x8 HBA could push more than 15GB/s. Indeed, if you compare the total possible PCIe throughput of those CPUs, 32x 4.0 is ~63GB/s, while 28x 5.0 gets you ~110GB/s.

    Unfortunately, we’re now at the mercy of what server designs these wind up in. I have to say though, I fully expect it is going to be smaller designs marketed as “edge” compute, like that Dell system.

  • qupada@kbin.socialtoTechnology@lemmy.ml•A Staggering 19x Energy Jump in Capacitors May Be the Beginning of the End for Batteries
    0·
    6 months ago

    Unfortunately what’s shipping today seems it would offer maybe half that.

    For the batteries that were announced this past week, a larger-than-refrigerator-sized cabinet held a capacity of around 15kWh.

    Around half the energy density by mass of Lithium batteries, and in the order of a sixth of the density by volume.

    Now if only we could come up with a system where your car could be charged while stopped at traffic lights, we might be onto a winner (:

    Considering however that the price of sodium is around 1-2% that of lithium, I expect we will see significant R&D and those numbers quickly start to improve.

  • qupada@kbin.socialtoTechnology@lemmy.world•DVD-like optical disc could store 1.6 petabits (or 200 terabytes) on 100 layers
    0·
    9 months ago

    Since the realistic competitor here is probably magnetic tape, current-generation (LTO9) media can transfer at around 400MB/s, taking 12 hours and change to fill an 18TB tape.

    Earlier archival optical disk formats (https://news.panasonic.com/global/stories/798) claimed 360MB/s, but I believe that is six, double-sided discs writing both sides simultaneously, so 30MB/s per stream. Filling the same six (300GB) discs would take about an hour and a half.

    Building the library to handle and read/write in bulk is always the issue though. The above optical system fit 1.9PB in the space of a server rack (and I didn’t see any options to expand further when that was current technology), and by the looks is 7 units that each can be writing a set of discs (call that 2.5GB/s total).

    In the same single rack you’d fit 560 LTO tapes (10.1PB for LTO9) and 21 drives (8.4GB/s).

    So they have a bit of catching up to do, especially with LTO10 (due in the next year or so) doubling the capacity and further increasing the throughput.

    There’s also the small matter that every one of these massive increases in optical disc capacity in recent years has turned out to be vapourware. I mean I don’t doubt that they will achieve it someday, but they always seem to go nowhere.

  • qupada@kbin.socialtoTechnology@lemmy.world•Toshiba exec claims hard drives are 7X cheaper than SSDs and will continually evolve for large datacenters
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    11 months ago

    There’s some space occupied by the servo tracks (which align the heads to the tap) in LTO, but if we ignore that…

    Current-generation LTO9 has 1035m of 12.65mm wide tape, for 18TB of storage. That’s approximately 13.1m², or just under 1.4TB/m².

    A 90 minute audio cassette has around 90m of 6.4mm wide tape, or 0.576m². At the same density it could potentially hold 825GB.

    DDS (which was data tape in a similar form factor) achieved 160GB in 2009, although there’s a lot more tape in one of those cartridges (153m).

    Honestly, you’d be better off using the LTO. Because they’re single-reel cartridges (the 2nd is inside the drive), they can pack a lot more tape into the same volume.