27
uyouthe
23d

Yes, that’s an M2 drive plugged in via usb 2.0. I dunno, maybe when you just need size over anything else maybe that’s ok but wasting all that work that ssd engineers put into making m2 drives so fast just feels stupid.

Comments
  • 4
    It's probably fine, most of the colorful drives in the CN series run at < sata 6 speeds.
  • 0
    jesus. christ. what
  • 9
    M.2 is just a physical interface, it can carry NVMe, but also SATA. Kind of makes sense for a single board computer like this one. You will be bottlenecked by USB 2.0 in terms of transfer rate for sure, but will probably still benefit from the higher IOPS.
  • 0
    I mean if it is cost effective and works ....
  • 0
    But it takes as much space as a 2.5" drive
  • 1
    @N00bPancakes it’s not cost effective at all
  • 1
    @electrineer Maybe, but then again it's powered by just one port whereas 2.5" SATA would require data and power. Plus, you can theoretically stick another M.2 on the same board. It's all up to what's required.
  • 0
    @kamen you can get usb-sata cables that power the drives that don't need the 12V rail (SSDs and 2.5" HDDs)
  • 0
    @uyouthe depends on your budget ;)
  • 1
    Makes a little more sense in a pi4
  • 0
    Eh depends on the application. 480mb/s is plenty for a lot of things.
  • 0
    @CoffeeSnake so 80 MB/s instead of 3500 MB/s but you paid for latter. Nice
  • 1
    @uyouthe don't need it don't sweat it ¯\_(ツ)_/¯
  • 0
    @kamen 2.5" SATA SSDs usually run fine with single USB power though. Damn SSDs have gotten cheap too, just seeing 10GB/€ just makes me wanna upgrade am the things
  • 0
    @uyouthe Also halve that speed if you want to get it off the pi. The usb controller gotta share with lan.
  • 1
    @LinusCDE really? Pi is like that?
  • 0
    @electrineer @CptFox Didn't know that, TIL. Haven't really thought about it, I guess the 12 V rail is there for backwards compatibility, otherwise you create needless confusion and would probably need to split this into two different standards. Better having something that you won't use (the 12 V) than not having it when you need it.
  • 0
    Is it m.2 nvme or m.2 ngff sata. If it is the latter, yes that's exactly how it was meant
  • 0
    @uyouthe Used to be like this, but with a Raspberry Pi 4 it is not shared anymore, this is the first Pi with true Gigabit LAN
  • 0
    @uyouthe Yeah. The usb bus is shared. Not sure on the pi 4 though. I had a nas on a Pi 3 and it was sufficient for streaming and such. But I could upload faster to youtube than the the hdd attached to the pi.

    The pi 4 basicially solves it though. I can use the full gigabit there. It currently has a sd for boot partition, ssd for os and 2 hdds in btrfs-raid1 for storage. Works flawless and is speedy.
  • 0
    Could just as easily be an M.2 SATA drive?
  • 0
    @kwilliams doesn’t matter because usb 2.0
  • 0
    @electrineer amperage usage is lower with M.2 than full-on SATA disks, even in SATA mode, and some 2.5" drives need a 12v rail still. Pis don't exactly respond well to high amperages, so saving on power draw where possible is best.
  • 1
    This is pretty much the only reason why Im not really into SBC's. There isnt a single affordable one who has a good higher speed interface like sata or pcie. Some of them have sata but looking a bit closer its mostly converted to USB 2.0 and then to the SOC. Why? Dont ask me! I didn't engineer it!
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