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  Topic Review (Newest First)
04-30-2019 07:13 PM
Simmons572
Quote: Originally Posted by CynicalUnicorn View Post
Might not be ideal, but it should work! Judging by the heatsink and somewhat high price tag, it looks like it's using some kind of PCIe switch.

@Simmons572 get in here this is your kind of shenanigans.

EDIT: I'm betting it's using an ASM1184e from ASMedia. A lot of mining motherboards with ridiculous amounts of PCIe slots use the ASM1187e in the same family, so I must assume it's a fairly affordable chip. Throughput doesn't matter for mining, but I suspect folding will take a hit. Each GPU would average 1.5% the bandwidth of a full 3.0 x16 link lol.
You're not wrong, this is intriguing

As far as I remember, there is a 1-5% performance difference when using the riser cards. I would imagine that the PCIe switching would affect the performance even further, such as cynical suggested. I'd be curious to see what the actual hit to performance looks like in reality.
04-29-2019 10:31 PM
CynicalUnicorn
Quote: Originally Posted by Cerberus View Post
https://www.amazon.com/Ubit-Riser-Ad...0746H1KY3?th=1


wonder if this would work with folding?
Might not be ideal, but it should work! Judging by the heatsink and somewhat high price tag, it looks like it's using some kind of PCIe switch.

@Simmons572 get in here this is your kind of shenanigans.

EDIT: I'm betting it's using an ASM1184e from ASMedia. A lot of mining motherboards with ridiculous amounts of PCIe slots use the ASM1187e in the same family, so I must assume it's a fairly affordable chip. Throughput doesn't matter for mining, but I suspect folding will take a hit. Each GPU would average 1.5% the bandwidth of a full 3.0 x16 link lol.
04-29-2019 09:27 PM
tictoc That splitter would definitely be a bottleneck, since it is sharing one PCI-e lane between four GPUs.

As @mmonnin said, running [email protected] with the fastest cards, you will see a slight performance drop (<10%) at PCI-e 3.0 x4. The bottleneck will increase as you step down the number of lanes and/or step up the GPU performance.
Right now I have a GTX 980, in a PCI-e 3.0 x8 slot, running a core_22 WU, and the average PCI-e throughput is around 3GB/s. That means that with a 980 I wouldn't really see any bottleneck at PCI-e 3.0 x4. With anything faster than a 980, you will start to see some performance loss at PCI-e 3.0 x4.
04-29-2019 08:06 PM
mmonnin A couple of years ago someone at [H] did some testing. Single digit % drop in PPD each step down either in # of lanes or PCI-E version.
04-29-2019 07:15 PM
k4m1k4z3
Quote: Originally Posted by Cerberus View Post
https://www.amazon.com/Ubit-Riser-Ad...0746H1KY3?th=1


wonder if this would work with folding?
In the past it has been true that there was little impact from using these. I was reading in the beta testing section of the folding forums that there have been some reports of slower performance on the core 22 units when using the x1 risers on higher end cards.

I have a single x1 to x16 riser laying around that I could test if needed
04-29-2019 06:47 PM
Cerberus
PCI-E x1 to 4x PCI-E x16

https://www.amazon.com/Ubit-Riser-Ad...0746H1KY3?th=1


wonder if this would work with folding?

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