Its not completely passive. A PCIE x16 slot has 16 data lanes, but only 1 set of control signals. Each x1 slot requires a set of control signals.
See pinouts:
http://pinouts.ru/Slots/pci_express_pinout.shtml
Topic: Passively splitting a single PCI-E 16x slot into 16 PCI-E 1x slots - page 2. (Read 27796 times)
June 17, 2013, 03:00:20 PM
June 17, 2013, 02:04:55 PM
Yeah. If this could be maass-manufactured. It could cost pennies per unit and be sold at reasonable prices for quite big profit.
June 17, 2013, 02:01:59 PM
I always wanted to try this, or even the pci-e risers for servers. I'm surprised with all the need for adding as many cards to a board that nobody has engineered a cheap solution that has like 16 ports. I've seen the rackmount pci-e servers for GPU processing, but they are redonkulous expensive.
June 17, 2013, 12:59:42 PM
YEAH! *gets enthused*
Except I don't have the money to buy a bunch of risers.
Except I don't have the money to buy a bunch of risers.
June 17, 2013, 12:46:16 PM
Only one way to find out 
.
. June 17, 2013, 12:30:38 PM
Hey guys.
I've been looking around places, and I've found these adapters that seem to split a single PCI-E 16x slot into two PCI-E 8x slots.
They look like this.
As you can see, on the bottom is a standard PCI-E 16x slot, and on the top is two PCI-E 16x slots that are running at 8X speed.
They're fairly expensive. (80 bucks on ebay) But I noticed one VERY IMPORTANT thing that they say about it.
The adapter is PASSIVE! If you look at the photo, there doesn't seem to be much circuitry on the board!
This leads me to believe that the PCI-E spec allows for passive splitting of lanes into at least two slower-speed lanes. The only problem is that normally, this is mechanically impossible. But what if you were to buy a couple of these...
http://www.ebay.com/itm/Powered-PCI-E-16x-16x-Riser-Cable-with-Molex-/111078375273?pt=LH_DefaultDomain_0&hash=item19dcc97f69
And then cut up the cable, and re-wire it to split one slot into two or more lower speed slots?
Once power draw problems are resolved. I think it would be EPIC for running a crapton of mining cards on a single system at very low cost. But only if the PCI-E spec actually allows it.
What do you think? Does anyone know? I haven't seen anything like this done before, so I don't know how well it would work.
~Re
I've been looking around places, and I've found these adapters that seem to split a single PCI-E 16x slot into two PCI-E 8x slots.
They look like this.
As you can see, on the bottom is a standard PCI-E 16x slot, and on the top is two PCI-E 16x slots that are running at 8X speed.
They're fairly expensive. (80 bucks on ebay) But I noticed one VERY IMPORTANT thing that they say about it.
The adapter is PASSIVE! If you look at the photo, there doesn't seem to be much circuitry on the board!
This leads me to believe that the PCI-E spec allows for passive splitting of lanes into at least two slower-speed lanes. The only problem is that normally, this is mechanically impossible. But what if you were to buy a couple of these...
http://www.ebay.com/itm/Powered-PCI-E-16x-16x-Riser-Cable-with-Molex-/111078375273?pt=LH_DefaultDomain_0&hash=item19dcc97f69
And then cut up the cable, and re-wire it to split one slot into two or more lower speed slots?
Once power draw problems are resolved. I think it would be EPIC for running a crapton of mining cards on a single system at very low cost. But only if the PCI-E spec actually allows it.
What do you think? Does anyone know? I haven't seen anything like this done before, so I don't know how well it would work.
~Re
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