3 ms·

Why would you need SATA when you have SD, also USB3 and Gigabit Ethernet? I have no problem booting from the SD then accessing data on my SATA drives using a US

Why would you need SATA when you have SD, also USB3 and Gigabit Ethernet? I have no problem booting from the SD then accessing data on my SATA drives using a USB-attached controller, also plan to get a NAS. Sure, it would be great to have connectors for everything and support for every cool standard but these guys have to give up all what is non-essential to keep it small, cheap and possible to engineer by a small team.

cogman10 6y ago
Honestly I just wish there was a faster standard than SD. 100MB/s for solid state is just incredibly slow now-a-days. There's no reason you couldn't kick SD transfer speeds up towards SSD speeds other than the protocol doesn't allow for it.
- blkbjhjkl 6y ago
  I wish folks would stop conflating boot media and root media. There's no reason your SD card has to consist of anything more than u-boot. SD is fantastically simple, so that the boot rom can get at a bootloader without much effort (generally the bootrom just looks at a memory offset on the mmc device). Once you start speaking newer faster protocols, this simplicity is lost. You're not likely going to find a bootrom that implements all the bits needed to get u-boot from a sata device. In a perfect world, once these are no longer developer devices, the mmc would be replaced with some spi flash (or even an emmc) with just u-boot. On 90% of embedded dev systems, you're better off thinking of the sd card as a "bios chip" then a hard drive. The fact you can also use it as a block device to store a rw filesystem is almost incidental, and should probably be avoided.
  - brucehoult 6y ago
    SD cards speak SPI. In fact SPI is all SiFive supported on their first 2018 HiFive Unleashed. As you say, it's good enough to bootstrap. That old board has gigE. Once you're up enough to TFTP you're away. I've never actually bothered to set that up on mine -- I boot a full kernel with NFS support and then switch to that.
  - imtringued 6y ago
    >There's no reason your SD card has to consist of anything more than u-boot. Oh, that's a nice idea! It would be nice if you linked to a guide or wiki page so that more people can replicate your setup.
- colejohnson66 6y ago
  CFast is CompactFlash, but with a SATA-based interface (up to ~600 MByte/sec) instead of IDE. It was designed because video cameras were making too much data for CF to handle. The downside is its size: 43x36x5 mm vs 15x11x1 mm for microSD. Also, CFast aren’t as ubiquitous as microSD. I can go to Target or Walmart and get a wide “selection” of microSD, but I’d be hard pressed to find a CFast card. So the chances of an SBC using CFast over eMMC or microSD is low.
- qwerty456127 6y ago
  The existence of Raspberry Pi as it is, Raspberry Pi 4 in parricular, is is a huge leap forward for the humanity already. The next leap is going to be the same kind of board but with no connectors besides an increasing number of full Thunderbolt 4 ports letting you connect anything you can imagine (incl as many GPIO connectors as you need). There is no need in a zoo of connectors like M.2, U.2, SATA, HDMI etc when we can conduct PCIe, DisplayPort and USB over a unified standard wire.
  - qwerty456127 6y ago
    By the way, switching to a single super-fast (for the time) connector for everything (including internal hard drives) was already anticipated before the invention of SATA and even USB2 - FireWire (IEEE 1394) was meant for that.
    - PaulDavisThe1st 6y ago
      Apple giveth. Apple taketh away.
  - tenebrisalietum 6y ago
    There's value in having GPIO pins not behind any bus or controller at all. Don't Thunderbolt controllers need firmware uploaded and such before they start working? How complex is Thunderbolt device and bus enumeration?
    - qwerty456127 6y ago
      Perhaps you're right. In fact I was going to write about connectors of 3 kinds: GPIO, dedicated fan connectors and Thunderbolt-enabled USB-C but then I came to the conclusion you can also put a GPIO controller or a fan on Thunderbolt the Occam's razor suggests we should only leave Thunderbolt - because we can. Apparently Apple thinks the same as it only left USB-C conectors on their recent laptops.
- panny 6y ago
  >Honestly I just wish there was a faster standard than SD There is one. It's called UFS 3.0. The Sony Xperia 1 II has it. They're same size as MicroSD, but look slightly different. https://store.shopping.yahoo.co.jp/rarahu-store/B085B2LTLB.html https://store.shopping.yahoo.co.jp/rarahu-store/B085B2LTLB.h...
tubularhells 6y ago
Because he wants to run a file server from it. This too was my first question.
- EamonnMR 6y ago
  I'm running a file server with a pi and a USB enclosure for a huge sata drive, and it works fine. Could be neater though.
  - tubularhells 6y ago
    Yeah, I like data integrity and failsafe setups, so your solution feels to me like standing on 3 stacked chairs while fixing something with live wire.
    - EamonnMR 6y ago
      It gets better, I'm powering the pi through its own powered USB hub. I was afraid doing so would short something but it's held up so far.
tenebrisalietum 6y ago
SD cards are fragile.

cogman10 6y ago

Honestly I just wish there was a faster standard than SD. 100MB/s for solid state is just incredibly slow now-a-days. There's no reason you couldn't kick SD transfer speeds up towards SSD speeds other than the protocol doesn't allow for it.

blkbjhjkl 6y ago
I wish folks would stop conflating boot media and root media. There's no reason your SD card has to consist of anything more than u-boot. SD is fantastically simple, so that the boot rom can get at a bootloader without much effort (generally the bootrom just looks at a memory offset on the mmc device). Once you start speaking newer faster protocols, this simplicity is lost. You're not likely going to find a bootrom that implements all the bits needed to get u-boot from a sata device. In a perfect world, once these are no longer developer devices, the mmc would be replaced with some spi flash (or even an emmc) with just u-boot. On 90% of embedded dev systems, you're better off thinking of the sd card as a "bios chip" then a hard drive. The fact you can also use it as a block device to store a rw filesystem is almost incidental, and should probably be avoided.
- brucehoult 6y ago
  SD cards speak SPI. In fact SPI is all SiFive supported on their first 2018 HiFive Unleashed. As you say, it's good enough to bootstrap. That old board has gigE. Once you're up enough to TFTP you're away. I've never actually bothered to set that up on mine -- I boot a full kernel with NFS support and then switch to that.
- imtringued 6y ago
  >There's no reason your SD card has to consist of anything more than u-boot. Oh, that's a nice idea! It would be nice if you linked to a guide or wiki page so that more people can replicate your setup.
colejohnson66 6y ago
CFast is CompactFlash, but with a SATA-based interface (up to ~600 MByte/sec) instead of IDE. It was designed because video cameras were making too much data for CF to handle. The downside is its size: 43x36x5 mm vs 15x11x1 mm for microSD. Also, CFast aren’t as ubiquitous as microSD. I can go to Target or Walmart and get a wide “selection” of microSD, but I’d be hard pressed to find a CFast card. So the chances of an SBC using CFast over eMMC or microSD is low.
qwerty456127 6y ago
The existence of Raspberry Pi as it is, Raspberry Pi 4 in parricular, is is a huge leap forward for the humanity already. The next leap is going to be the same kind of board but with no connectors besides an increasing number of full Thunderbolt 4 ports letting you connect anything you can imagine (incl as many GPIO connectors as you need). There is no need in a zoo of connectors like M.2, U.2, SATA, HDMI etc when we can conduct PCIe, DisplayPort and USB over a unified standard wire.
- qwerty456127 6y ago
  By the way, switching to a single super-fast (for the time) connector for everything (including internal hard drives) was already anticipated before the invention of SATA and even USB2 - FireWire (IEEE 1394) was meant for that.
  - PaulDavisThe1st 6y ago
    Apple giveth. Apple taketh away.
- tenebrisalietum 6y ago
  There's value in having GPIO pins not behind any bus or controller at all. Don't Thunderbolt controllers need firmware uploaded and such before they start working? How complex is Thunderbolt device and bus enumeration?
  - qwerty456127 6y ago
    Perhaps you're right. In fact I was going to write about connectors of 3 kinds: GPIO, dedicated fan connectors and Thunderbolt-enabled USB-C but then I came to the conclusion you can also put a GPIO controller or a fan on Thunderbolt the Occam's razor suggests we should only leave Thunderbolt - because we can. Apparently Apple thinks the same as it only left USB-C conectors on their recent laptops.
panny 6y ago
>Honestly I just wish there was a faster standard than SD There is one. It's called UFS 3.0. The Sony Xperia 1 II has it. They're same size as MicroSD, but look slightly different. https://store.shopping.yahoo.co.jp/rarahu-store/B085B2LTLB.html https://store.shopping.yahoo.co.jp/rarahu-store/B085B2LTLB.h...

tubularhells 6y ago

Because he wants to run a file server from it. This too was my first question.

EamonnMR 6y ago
I'm running a file server with a pi and a USB enclosure for a huge sata drive, and it works fine. Could be neater though.
- tubularhells 6y ago
  Yeah, I like data integrity and failsafe setups, so your solution feels to me like standing on 3 stacked chairs while fixing something with live wire.
  - EamonnMR 6y ago
    It gets better, I'm powering the pi through its own powered USB hub. I was afraid doing so would short something but it's held up so far.

tenebrisalietum 6y ago

SD cards are fragile.