Zarathustra[H]
Extremely [H]
- Joined
- Oct 29, 2000
- Messages
- 40,582
PCIe Switches are a thing. They are expensive, use power, and introduce some latency, but they exist and work.
PLX was probably the most famous until they were absorbed by Broadcom, but there are other brands as well. I believe TI makes some, and there is also a company named Microchip that appears to be in the market.
We often se them integrated into enterprise hardware (either motherboards or SAS controllers, etc)
The question is, are there any general purpose risers one could use?
An example use case could be as follows:
Your motherboard has a 4x Gen5 or 4x Gen4 slot. You need to use an 8x Gen3 expansion card. The 4x Gen5 and Gen4 slots have more than enough bandwidth to support the 8x Gen3 card, but if you just install it, it is going to run in 4x Gen3 mode and choke.
The solution would be a PCIe switch riser that inserts into the slot, and communicates with the motherboard at 4x Gen5 or Gen4 speeds, and converts all of that bandwidth to 8x Gen3, allowing the 8x Gen3 expansion card to work at full bandwidth.
This could be either a straight up riser allowing for the use of a half height card on top of it, or it could use a cable and breakout board to allow you to install the 8x gen3 card somewhere else.
Heck, in the case of the latter, it could even be designed to go into a gen5 or gen4 m.2 slot.
The technology to do this exists, but the question is, has anyone actually done it?
I'd happily pay a few hundred dollars for something like this. I can't be the only one.
I've done some googling, but all I can find are some half-assed mining adapters that look like they would be crap. Has anyone seen anything better?
The closest I have found thus far is this one electrical engineer in Germany who seems to run his own business:
https://c-payne.com/collections/pcie-packet-switch-adapters-gen4
His products are pretty cool, but are quite overkill for what I have in mind.
PLX was probably the most famous until they were absorbed by Broadcom, but there are other brands as well. I believe TI makes some, and there is also a company named Microchip that appears to be in the market.
We often se them integrated into enterprise hardware (either motherboards or SAS controllers, etc)
The question is, are there any general purpose risers one could use?
An example use case could be as follows:
Your motherboard has a 4x Gen5 or 4x Gen4 slot. You need to use an 8x Gen3 expansion card. The 4x Gen5 and Gen4 slots have more than enough bandwidth to support the 8x Gen3 card, but if you just install it, it is going to run in 4x Gen3 mode and choke.
The solution would be a PCIe switch riser that inserts into the slot, and communicates with the motherboard at 4x Gen5 or Gen4 speeds, and converts all of that bandwidth to 8x Gen3, allowing the 8x Gen3 expansion card to work at full bandwidth.
This could be either a straight up riser allowing for the use of a half height card on top of it, or it could use a cable and breakout board to allow you to install the 8x gen3 card somewhere else.
Heck, in the case of the latter, it could even be designed to go into a gen5 or gen4 m.2 slot.
The technology to do this exists, but the question is, has anyone actually done it?
I'd happily pay a few hundred dollars for something like this. I can't be the only one.
I've done some googling, but all I can find are some half-assed mining adapters that look like they would be crap. Has anyone seen anything better?
The closest I have found thus far is this one electrical engineer in Germany who seems to run his own business:
https://c-payne.com/collections/pcie-packet-switch-adapters-gen4
His products are pretty cool, but are quite overkill for what I have in mind.
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