• Redjard@lemmy.dbzer0.com
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    5 days ago

    M.2 nvme uses PCIe lanes. In the last few generations both AMD and intel were quite skimpy with their PCIe lane offering, generally their consumer CPUs have only around 20-40 lanes, with servers getting over 100.
    In the default configuration, nvme gets 4 lanes, so usually your average CPU will support 5-10 M.2 nvme SSDs.
    However, especially with PCIe 5.0 now common, you can get the speed of 4 PCIe 3.0 lanes in a single 5.0 lane, so you can easily split all your lanes dedicating only a single lane per SSD. In that configuration your average CPU will support 20-40 drives, with only passive adapters and splitters.
    Further you can for example actively split out PCIe 5.0 lanes into 4x as many 3.0 lanes, though I have not seen that done much in practice outside of the motherboard, and certainly not cheaply. Your motherboard will however usually split out the lanes into more lower-speed lanes, especially on the lower end with only 20 lanes coming out of the CPU. In practice on even entry-level boards you should count on having over 40 lanes.

    As for price, you pay about 30USD for a pcie x16 to 4 M.2 slot passive card, which brings you to 6 M.2 slots on your average motherboard.
    If you run up against the slot limit, you will likely be using 4TB drives and paying at the absolute lowest a grand for the bunch. I think 30USD is an acceptable tradeoff for a 20x speedup almost everyone on this situation will be taking.
    If you need more than 6 drives, where you would be looking at a pcie sata or sas card previously, you can now get x16 pcie cards that passively split out to 8 M.2 slots, though the price will likely be higher. At these scales you almost certainly go for 8TB SSDs too, bringing you to 6 grand. Looking at pricing I see a raid card for 700usd, which supports passthrough, i.e. can act as just a pcie to M.2 adapter. There are probably cheaper options, but I can’t be bother to find any.

    Past that there is an announced PCIe x16 to 16 slot M.2 card, for a tad over 1000usd. That is definitely not a consumer product, hence the price for what is essentially still a glorified PCIe riser.

    So if for some reason you want to add tons of drives to your (non-server) system, nvme won’t stop you.

    • WhyJiffie@sh.itjust.works
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      4 days ago

      that’s good to be aware of, but using nvme drives for lots of storage does not seem to be economical. (I assume) in most cases large amounts of storage like this is used for archival and backups, where speeds don’t matter over what good HDDs can do.

      • Redjard@lemmy.dbzer0.com
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        4 days ago

        Oh yeah absolutely. As mentioned above I myself use spinning rust in my nas.
        The difference is decreasing over time, but it’ll be ages before ssds trump hdds in price per TB.

        The difference now compared to in the past is that you are looking at 4TB SSDs and 16TB HDDs, not 512GB SSDs and 4TB HDDs, and in my observation the vast majority has no use for that amount of storage currently, while the remainder is willing or even happy to offload the storage onto a separate machine with network access, since the speed doesn’t matter and it’s the type of data you might want to access rarely but from anywhere on any kind of device.
        Compare for example phones that are trying to sell you 0.25 or 0.5 TB as a premium feature for hundreds of usd in upmark.
        If anyone had use for 2TB of storage, they would instead start at 0.5 and upsell you to 2 and 4 TB.

        I myself have 32TB of storage and am constantly asking around friends and family if anyone has large amounts of data they might wanna put somewhere. And there isn’t really anyone.
        Even the worst games only use up so many TB, and you don’t really wanna game off of HDD speeds after tasting the light. And if you’d have to copy your game over from your HDD, the time it’d take to redownload from steam is comparable unless your internet is horrifically bad.
        My extensive collection of linux ISOs is independent and stable, and I do actually share it with a few via jellyfin, but in all its greatness both in amount and quality it still packs in below 4TB. And if you wanna replicate such a setup you’d wanna do it on a dedicated machine anyway.

        If I had to slim down I could fit my entire nas into less than 4TB if I’m being honest with myself, in my defense I built it prior to cost-effective 4TB SSDs. The main benefit for me is not caring about storage. I have auto backups of my main apps on my phone, which copy the entire apk and data directories, daily, and move them to the server. That generates about 10GB per day.
        I still haven’t bothered deleting any of those, they have just been accumulating for years. If I ever get close to my storage capacity, before buying another drive I’d first go in and delete the 6TB of duplicate backups of random phone apps dated 2020-2026.
        I wrote a paper grouping together info of tons of simulations. And instead of taking out the measurement files containing the relevant values every 10 simulation steps (2.5GB), or the data of all system positions and all measured quantities every 2 steps (~200GB), I copied the entire runtime directory. For 431 simulations, 8.5GB per, totaling 1.8TB.
        And then later my entire main folder for that entire project and the program data and config dirs of the simulation software, for another half a TB. I could have probably saved most of that by looking into which files contain what info and doing some most basic sorting. But why bother? Time is cheap but storage is cheaper.

        But to go for simply the feeling of swimming in storage capacity, you first need to experience it. Which is why I think noone wants it. And those that do already have a nas or similar setup.

        Maybe you see a usecase that would see someone without knowledge or equipment need tons of cheap storage in a single desktop pc?

        • WhyJiffie@sh.itjust.works
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          4 days ago

          Maybe you see a usecase that would see someone without knowledge or equipment need tons of cheap storage in a single desktop pc?

          Personally I have 4 TB and some in the PC, and it’s almost full. a few VMs, a couple of snapshots, music because I prefer a local player over jellyfin, almost all programs that I didn’t want to keep on my small SSD, and a bunch of other data.

          I know someone who wanted to save his dashcam recordings to his PC. I could not get him to tell why does he want it, and figure out if it would be important enough to get a big drive, but currently he can only store 2 days of recordings on the SSD. People around me are often on a tight budget, and I didn’t want to buy him an SSD unnecessarily big (before I got to know he wants to do this…), both for the cost and the lower lifespan

          • Redjard@lemmy.dbzer0.com
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            4 days ago

            because I prefer a local player over jellyfin

            I used vlc then mpv for years before setting up jellyfin. I could still use them if I wanted to.
            For internet access, the largest of files (~30Mbit/s) came up against my upload limit, but locally still played snappily.
            Scrubbing through files was as snappy as playing off of my ssd.

            I do understand wanting music locally. I sync my music locally to my phone and portable devices too so I’m not dependent on internet connectivity. None of these devices even support hdds however, for my pc I see no reason not to play off of my nas using whatever software I prefer.

            I didn’t want to buy him an SSD unnecessarily big […] for the lower lifespan

            Larger ssds almost always have higher maximum writes. If you look at very old (128 or 256GB drives from 2010-2015 ish) or very expensive drives you will get into higher quality nand cells, but if you are on a budget you can’t afford the larger ones and the older ones may have 2-3 times the cycles per cell but like a tenth the capacity, so still 1/3rd the total writes.
            The current price optimum to my knowledge is 2TB SSDs for ~85USD with TLC up to 1.2PBW, so about 600 cycles. If you plan on a lifetime of 10 years, that is 330GB per day, or 4GB/day/USD. I can’t even find SLC on the market anymore (outside of 150USD 128GB standalone chips), but I have never seen it close to that price per bytes written. (If you try looking for slc ssds, you will find incorrectly tagged tlc ssds, with tlc prices and lifetime. That is because “slc cache” is a common ssd buzzword).

            I didn’t want to buy him an SSD unnecessarily big […] for the cost

            Another fun thing about HDDs is that they have a minimum price, since they are large bulky chunks of metal that are inherently hard to manufacture and worth their weight in materials.
            That lower cutoff seems to be around 50USD, for which you can get 500GB or 2TB at about the same price. 4TB is sold for about 90USD.
            In terms of price, ignoring value just going for the cheapest possible storage, there is never a reason to by an HDD below 2TB for ~60USD. A 1TB SSD has the same price as a 1TB HDD, below that SSDs are cheaper than HDDs.

            So unless your usecase requires 2TB+, SSDs are a better choice. Or if it needs 1TB+ and also has immensely high rewrite rates.

            a few VMs, a couple of snapshots

            I have multiple complete disk images of various defunct installs, archived on my nas. That is a prime example for stuff to put into network storage. Even if you use them, loading them up would be comparable in speed to doing it off of an HDD.

            • WhyJiffie@sh.itjust.works
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              2 days ago

              for music what I use is AIMP. I only hope it can work with wine because I don’t want to run a VM for it

              So unless your usecase requires 2TB+, SSDs are a better choice. Or if it needs 1TB+ and also has immensely high rewrite rates.

              that’s good to know, it’ll keep this in mind. thanks!

              I have multiple complete disk images of various defunct installs, archived on my nas. That is a prime example for stuff to put into network storage. Even if you use them, loading them up would be comparable in speed to doing it off of an HDD.

              does this also stand for when shares are done with SMB? I’m mostly worried about random access there being worse than with a local HDD

              • Redjard@lemmy.dbzer0.com
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                2 days ago

                Smb should be fine. I used it for years on my primary systems (I moved to sshfs when I migrated to linux finally), and it wasn’t ever noticeably less performant than local disks.
                Compared to local ntfs partitions anyway, ntfs itself isn’t all that fast in file operations either.

                If you are looking at snapshots or media, that is all highly sequential and low file operations anyway. Something like gaming off of a nas via smb does also work, but I think you notice the lag smb has. It might also be iops limitations there.

                Large filesizes and highly random fast low-latency reads is a very rare combination to see. I’d think swap files, game assets, browser cache (usually not that large to be fair).

                For anything with fewer files and larger changes it always ran at over 100MiB/s for me until I exhausted the disk caches, so essentially the theoretical max accounting for protocol losses.

                for music what I use is AIMP. I only hope it can work with wine because I don’t want to run a VM for it

                I use that on android. Never knew there were desktop versions, odd that it supports android but not other linux.
                Wine is very reliable now, it will almost certainly work out of the box.
                Otherwise there are also projects to run android apps on linux, though no doubt at much more effort and lower chance of success than wine.