Originally Posted by DNMock
I'm not too sold on it to be honest. Sure it might be ok for 1 slot, but once you start pushing 300 watts (a pair of 6+2 pin connectors) to 4 slots, that's a ton of power running through the motherboard itself and bound to make it extremely difficult to build without at least some interference.
If you are just gonna put all those power connectors on the board instead of the cards then you still have the cable management issues and now you have pretty much ensured that the only way to get 2 or more GPU's is to go with an E-ATX board due to all the space those connectors are gonna eat up.
Maybe once SATA gives up the ghost freeing up some space though it might be more feasible.
edit: Now if you wanna just up the power a little to all the slots so that more lower power GPU's can ship without power connectors, I'm totes on board there, just not with throwing out the PCIE power connector to GPU standard all together is all.
I'd suggest starting with doubling the PCI-E slot power standard from 75w to 150w, drop the 6pin auxilary PCI-E connector, and keep the 8pin for the rare card that actually draws more than 150w (yes, the medium and high end GPUs we all love here are indeed RARE in the grand scheme of computers). That would barely require any changes other than a few more pins added to the slot. Easy stuff there that will cut out a HUGE number of cables
As for everything else, theres really no reason we couldn't
eliminate the rest of the cables, but it would require a much large change to the ATX standard and would require much more cooperation from industry players, as well as causing a short but valid pain point for end users while the new and old standards briefly coexist. I'm personally all for making that push, but I'd gladly settle for smaller incremental changes like the one i mentioned above instead, if that's all the industry was willing to do.
To address some of the specific points you mentioned:
multi-GPU is already practically dead, and it literally never made sense for low or mid tier GPUs to begin with (the type that would actually be drawing their power off the interconnect). The only scenario where this might actually be an issue is with dedicated mining or other heavy GPU compute systems, and there are already special made motherboards and various other solutions for those rather exotic and specific systems.
Interfearance and enlarged motherboards are a total non-issue. Boards can be made a few layers thicker to allow more traces without getting particularly close to anything sensitive. Better yet, the back side of most motherboards are completely unused, and could easily support shielded surface conductors physically isolated from the board by a small air gap, and would only contact the board in at their beginning and end points.
Keep in mind that boards with 5 pci-e slots are already by standard capable of putting a total of 375w through pci-e. that's already more than the total power consumption of most
entire computers. Simply routing more of those power traces to the 2 "GPU" slots and less to the remaining slots would already go a long way to solving the problem without budgeting any more total current carrying capacity whatsoever. I don't suggest this of course, as there are easy solutions to allow every slot to get a full 150w capacity, but it goes to show that even current motherboards can supply a huge ammount of power, and are simply not configured in a way that lends itself to typical modern usage (one or two power hungry cards, rather than the ancient paradigm behind the ATX and subsequently PCI-E standard of having a half dozen very low powered cards)
Originally Posted by looniam
heat generation and electrical interference would like to have a word w/you.
btw, with the pci-e 4.0 standard has also come specs for more external power connections, rising the limit to 300+ watts as the previous 225 watts limited was already exceeded. though with your POV i can see why people though it referred to the slot
a motherboard is a SIGNAL BUS not a power supply/service panel!
Oh really? So the hundreds of watts that are already distributed through a motherboard are purely signaling? Gee, that's facinating.
No, the motherboard is not merely a signal bus. It is the platform which supports anything and everything we choose to throw at it. The only
reason so many various power connections external to the motherboard even exist is because the standards that boards are beholden to moves far slower than the computer industry as a whole. Computers got more fans and more drives, and thus molex and floppy and 3/4 pin fan connectors cropped up to address this sudden need for power that wasnt factored into the AT standard. The ATX standard finally rolled aound in the 90s to bring things more in line with how computers were actually being used, and we got the 20 pin. Then we needed more and we tacked on a 4 pin, then a 6 pin, then sata drives became a thing and we tacked on data power, then AGP started eating more power and fan headers started moving onto motherboards and adding even more supplemental power to the board was getting absurd and we threw out all the old board connections in favor of the fancy new 24 pin we all know and love today... and guess what? That was 16 years ago. now we've got even more cabled added to the mix, not
because we couldn't
make a more elegant solution, but because we didn't
standardize one quickly enough and by the time the next revision to the standard rolled around 4 years later the various janky temporary solutions had already proliferated the industry and were absurbed into the standard rather than replaced. Simply put, computers standards today are a result of years of bloat between new standards, rather than a product of intelligent design. Its time to change those standards to reflect the needs of 2019, not 1989.
No, I dont think that you can put 225 not 300w through the slot currently (nor did I ever say that, perhaps read before typing), I think we should
be able to put more than 75w through the slot as cards in excess of 75w are extremely common and the limiting factor to doing so is adhearance to the current standards rather than an inability to physically supply said currenty through a minimally redesigned and still backwards compatible interface.