Skip Navigation
A call to replace air conditioners with heat pumps in California
  • It is a good question.

    Where I live, electricity costs around $0.28/kWh, but generation is typically >85% renewable (predominantly hydroelectric).

    My heat pump (4.7 COP when heating) would cost $0.06 to run for every 1kWh of heat it produces, with only 0.03kWh of that electricity coming from fossil fuel sources.

    Gas - which I don't have at my house - would have pricing in the neighbourhood of $0.15/kWh. Even at 95% efficiency getting 1kWh of heat from gas would cost $0.16, using 1.05kWh of gas.

    35x the fossil fuel usage and 2.5x the price, for the same quantity of heat. Some luck of living in a moderate climate where an air-source heat pump almost never loses efficiency, to be fair.

  • EPYC for Desktop: It's finally here! (and cheap too)
  • 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.

  • What Convinced You To Pick Xbox In The First Place?
  • I'm still convinced the person who chose the location of the sticks on the PS2's controller had never seen human hands before. Or at the very least, they weren't at all aware which direction our thumbs bend in.

  • A Staggering 19x Energy Jump in Capacitors May Be the Beginning of the End for Batteries
  • 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.

  • A Staggering 19x Energy Jump in Capacitors May Be the Beginning of the End for Batteries
  • I've been seeing a lot about Sodium-ion just in the past week.

    While they seem to have a huge advantage in being able to charge and discharge at some fairly eye-watering rates, the miserable energy density would seem to limit them to stationary applications, at least for now.

    Perfect for backup power, load shifting, and other power-grid-tied applications though.

  • Asking a Linux user to recommend a printer
  • Sharp also make great commerical-grade printers that are 100% Linux compatible, we're using these at work: http://global.sharp/products/copier/products/bp_70c65/index.html

    They don't really make anything small enough to be a "home" model, this looks like their smallest printer: https://global.sharp/products/copier/products/mx_c358f/index.html (and that's around $1000, if you could even find someone to sell you one).

  • Amazon refusing to show me the price of something if I do not add it to cart
  • Without giving Amazon too much of the benefit of the doubt here, I've noticed they love to offer you "coupons", generally with a midnight expiry.

    I expect it's 100% a tactic to get you to commit to something you've looked at a couple of times but might be on the fence about buying.

    I get the same as OP's logged-out price (nothing hidden) while logged in, perhaps if they are offering a coupon it would take it below the minimum advertised price.

    Definitely stupid, but it's the only way I can see of arriving at this situation.

  • A DisplayPort Port That You Can Plug HDMI Into
  • eSATAp! What a wild combination.

    Not actually a terrible idea, even if it frequently was limited to powering 2.5" drives due to a lack of 12V. Some had extra contacts for that, but most that I saw didn't.

  • Elon Musk finally says something we can all agree on: No one wants to have to log in with a Microsoft Account on Windows 11
  • It does however affect getting updates from government agencies, and others who insist on only disseminating real-time information to the public via Twitter.

    For instance: https://twitter.com/WakaKotahiWgtn

    This is the account for traffic events (road closures, traffic accidents, etc) in my city. Not signed in, the latest visible post is from February 2023.

    Since I don't have a twitter account, this is now functionally useless.

  • Deleted
    Reliable, easy to use Linux OS
  • It can be a one-time setup.

    Right up until your laptop gets its motherboard replaced and won't boot due to a MOK-signed module (in my case it was ZFS, which I needed for the machine to actually function).

    At which point you

    • Switch secure boot from enforcing to permissive mode (note you can't turn it off entirely, or the enrollment will fail with an error that your system doesn't support secure boot).
    • Boot into your OS.
    • Find the arcane command to re-enroll the MOK. That's sudo mokutil --import /var/lib/shim-signed/mok/MOK.der (for Ubuntu derivatives and probably others), in case someone finds this post in the future.
    • Reboot again, accept enrolling the key.
    • Reboot again, and switch back to enforcing.

    If you have a BIOS password, encrypted filesystem, and all the other moving parts that make having secure boot enabled actually a meaningful exercise, this is neither a fun, nor particularly quick process.

    As for modules being signed automatically when built by DKMS, I've never had an issue with that.

  • DVD-like optical disc could store 1.6 petabits (or 200 terabytes) on 100 layers
  • 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.

  • Samsung purposely knives customer's TV to weasel out of repair
  • From the video description:

    I have been a Samsung product user for many years, and I don't plan to stop anytime soon

    And all sympathy I had for this person just vanished. If you don't demand better, they will keep doing - and getting away with - shit like this.

    Voting with your wallet might be the one voice you have left in this world, what a way to squander it by continuing to buy products from companies whose representatives behave in this manner.

  • My sister’s 16 yr old bengal, Tica
  • I was going to say out of Half Life (as in the 1998 original), so we're clearly thinking about much the same era :)

    I think it's the slightly crispy edges where the blurred background starts, combined with the overall... flat... appearance.

    Cute cat though.

  • Mark Zuckerberg indicates Meta is spending billions of dollars on Nvidia AI chips
  • The estimated training time for GPT-4 is 90 days though.

    Assuming you could scale that linearly with the amount of hardware, you'd get it down to about 3.5 days. From four times a year to twice a week.

    If you're scrambling to get ahead of the competition, being able to iterate that quickly could very much be worth the money.

  • InitialsDiceBearhttps://github.com/dicebear/dicebearhttps://creativecommons.org/publicdomain/zero/1.0/„Initials” (https://github.com/dicebear/dicebear) by „DiceBear”, licensed under „CC0 1.0” (https://creativecommons.org/publicdomain/zero/1.0/)QU
    qupada @kbin.social
    Posts 0
    Comments 103