4 ms·

Would be interesting if the new standard was just multiple USB-C connectors for the cards. One, two, four or eight of them depending on the bandwidth requiremen

Would be interesting if the new standard was just multiple USB-C connectors for the cards. One, two, four or eight of them depending on the bandwidth requirements.

lightedman 9y ago
The alignment issues of multiple on-board plugs would just be a headache waiting to happen. Even with SMT components typically aligning themselves during solder flow, there's always discrepancies in manufacturing and components go ever so slightly out of whack. On the GPU side, those would probably be straight because they'd be laid flat against the board, perpendicular to the motherboard. The motherboard mountings would be the problematic ones.
- wlesieutre 9y ago
  You could plug all the sockets into a large retainer (mimicking the role of a GPU) during soldering to ensure they're spaced correctly. Doesn't sound as solid as a socket though, they support some weight of the card in addition to carrying data. I'd be concerned about USB sockets getting torqued off if you looked at them wrong while installing a card, or if you took out the mounting screws without having the card properly supported.
  - astrodust 9y ago
    USB-style sockets could require less force to insert than a typical card, so they're less likely to break, but that's also a function of design. A plastic sleeve to guide the card into place and ensure a good fit isn't that hard a concept.
    - wlesieutre 9y ago
      Force to insert it isn't what I'm worried about, it's snapping it off with perpendicular force. Double height GPUs are heavy and most of that's supported by hanging off the socket.
      - astrodust 9y ago
        Any heavy-weight CPU would have 4 or 8 sockets holding it up, so that shouldn't be an issue. If all that weight was hinging on one socket an accommodation to have some kind of flange wouldn't be too hard to incorporate.
        wlesieutre 9y ago
        True, you could still run the PCB footprint out to the edge and have a support socket on the motherboard to grab it. Then we could eliminate the cost of the USB components by building contacts into the support socket that connect to pads on the PCB! I dunno, ease of inserting and removal just isn't on my list of desires for a GPU. I install one maybe every 2 years, and I don't want to worry about it falling out and smashing around inside my case if I pick up my computer or something. Whatever mounting shenanigans are necessary to lock it in place with weaker connectors feels like a solution looking for a problem. The somewhat high force of PCIe slots is a feature, not a bug.
- astrodust 9y ago
  The socket compoonents would have to be manufactured as one part that's soldered down into existing holes not unlike how the slot itself is a single component.
amluto 9y ago
USB-C is a fancy and quite complicated standard that is complicated mostly because it can negotiate varying link protocols and because it can handle being connected in two or four different orientations [1]. For PCIe slots, it's always PCIe and it's always plugged in the same direction, so USB-C wouldn't buy much. [1] USB-C to USB-C cables don't have the symmetry they appear to have. Each end can be independently upside down.
- gugagore 9y ago
  to clarify your [1], if I take two connected devices, unplug the cable, and plug it back in, reversing each of the two plugs, then that is a different configuration from what I started with?
  - amluto 9y ago
    Yes, if I understood it correctly when I read the spec. (To be clear, this means turning both ends upside down, not switching which end is which.) IIRC, this means that certain USB-C configurations require a captive cable because they can only tolerate reversal of one end, not both.

Would be interesting if the new standard was just multiple USB-C connectors for the cards. One, two, four or eight of them depending on the bandwidth requirements.

lightedman 9y ago

The alignment issues of multiple on-board plugs would just be a headache waiting to happen. Even with SMT components typically aligning themselves during solder flow, there's always discrepancies in manufacturing and components go ever so slightly out of whack. On the GPU side, those would probably be straight because they'd be laid flat against the board, perpendicular to the motherboard. The motherboard mountings would be the problematic ones.

wlesieutre 9y ago
You could plug all the sockets into a large retainer (mimicking the role of a GPU) during soldering to ensure they're spaced correctly. Doesn't sound as solid as a socket though, they support some weight of the card in addition to carrying data. I'd be concerned about USB sockets getting torqued off if you looked at them wrong while installing a card, or if you took out the mounting screws without having the card properly supported.
- astrodust 9y ago
  USB-style sockets could require less force to insert than a typical card, so they're less likely to break, but that's also a function of design. A plastic sleeve to guide the card into place and ensure a good fit isn't that hard a concept.
  - wlesieutre 9y ago
    Force to insert it isn't what I'm worried about, it's snapping it off with perpendicular force. Double height GPUs are heavy and most of that's supported by hanging off the socket.
    - astrodust 9y ago
      Any heavy-weight CPU would have 4 or 8 sockets holding it up, so that shouldn't be an issue. If all that weight was hinging on one socket an accommodation to have some kind of flange wouldn't be too hard to incorporate.
      - wlesieutre 9y ago
        True, you could still run the PCB footprint out to the edge and have a support socket on the motherboard to grab it. Then we could eliminate the cost of the USB components by building contacts into the support socket that connect to pads on the PCB! I dunno, ease of inserting and removal just isn't on my list of desires for a GPU. I install one maybe every 2 years, and I don't want to worry about it falling out and smashing around inside my case if I pick up my computer or something. Whatever mounting shenanigans are necessary to lock it in place with weaker connectors feels like a solution looking for a problem. The somewhat high force of PCIe slots is a feature, not a bug.
astrodust 9y ago
The socket compoonents would have to be manufactured as one part that's soldered down into existing holes not unlike how the slot itself is a single component.

amluto 9y ago

USB-C is a fancy and quite complicated standard that is complicated mostly because it can negotiate varying link protocols and because it can handle being connected in two or four different orientations [1]. For PCIe slots, it's always PCIe and it's always plugged in the same direction, so USB-C wouldn't buy much. [1] USB-C to USB-C cables don't have the symmetry they appear to have. Each end can be independently upside down.

gugagore 9y ago
to clarify your [1], if I take two connected devices, unplug the cable, and plug it back in, reversing each of the two plugs, then that is a different configuration from what I started with?
- amluto 9y ago
  Yes, if I understood it correctly when I read the spec. (To be clear, this means turning both ends upside down, not switching which end is which.) IIRC, this means that certain USB-C configurations require a captive cable because they can only tolerate reversal of one end, not both.