magic-blue-smoke
Which m.2 variants for manufacturing?
This issue is to separate desktop PCIe here /issues/4 and m.2 variants
Dual Edge TPU to m.2 adapter is possible in following configurations:
- m.2 A+E key 2242. This form-factor is non-standard (standard is 2230 for A/E keys) - you need to check clearance for longer card
- m.2 B+M key 2242, 2260 and 2280.
Putting all of those into production is not easy, please let me know:
- which key and form factor you'd prefer
- quantity
i think the 2280 and the native x1 pcie version are the most favorable in this case. i dont see any market for a 2242 A+E card. i think a 2230 a+e with a riser would be more practicable.
@wmchris now I have the same feeling, but before that I was thinking Coral Dual TPU B+M adapter should be most popular for Rock Pi's and other SBC with m.2 B key slot. I was wrong: most adapters went to PCIe slot with another COTS NVMe-to-PCIe adapter. Will see how it goes :) Surely m.2 2280 B+M version seems not only more favorable, but also less constrained to manufacture
I was wrong: most adapters went to PCIe slot with another COTS NVMe-to-PCIe adapter. Will see how it goes :)
well the reason is, that the native nvme slot supplies 4 pcie lanes, while your adapter shrink it to 1 pcie lane. in my case the pcie x1 slot on the mainboard is unused, as on most builds, while the nvme slots are occupied in the most cases
I'm interested in a m.2 A+E key adapter at either length.
EDIT: I was wrong. Everybody else was right. The B+M will be more useful. I'm looking for a PCIe and B+M adapters.
I'm interested of B+M key adapter. Hope can get dual TPU recognized with this in HP elitedesk as with onboard NIC m.2 e-key it didn't work - not even recognized Edit: HP informed m.2 E-key 2280 slot work only with selected wlan cards
I'm also interested in B+M Key Variant. I have a NanoPi M4v2 that has a daughter board for NVMe B+M Key with PCIe 2.1 x2 Lanes. Does somebody know if there's a cheap e-key to b+m-key adapter that routes both pcie lanes through for dual edge tpu without any switch IC? Would it be difficult to design a simple passive adapter myself that routes both lanes?
Board: https://www.friendlyarm.com/index.php?route=product/product&product_id=268 NVMe Adapter: https://www.friendlyarm.com/index.php?route=product/product&product_id=262
Does somebody know if there's a cheap e-key to b+m-key adapter that routes both pcie lanes through for dual edge tpu without any switch IC? Would it be difficult to design a simple passive adapter myself that routes both lanes?
you cant simply create a passive adapter, as a general m-keyed m2 has only one pcie bus. coral requires 2.
I'm also interested in B+M Key Variant. I have a NanoPi M4v2 that has a daughter board for NVMe B+M Key with PCIe 2.1 x2 Lanes. Does somebody know if there's a cheap e-key to b+m-key adapter that routes both pcie lanes through for dual edge tpu without any switch IC? Would it be difficult to design a simple passive adapter myself that routes both lanes?
Board: https://www.friendlyarm.com/index.php?route=product/product&product_id=268 NVMe Adapter: https://www.friendlyarm.com/index.php?route=product/product&product_id=262
@KingKoro you can design semi-passive adapter only if SoC supports PCIe bifurcation, ie PCIe x2 has to be split into 2xPCIe x1 in hardware. Contact manufacturer to see if it’s possible. Another issue is that there is only one clock line, while Dual Edge TPU requires two and you’d need clock fanout driver IC, that’s why it’s “semi-passive”
@KingKoro you can design semi-passive adapter only if SoC supports PCIe bifurcation, ie PCIe x2 has to be split into 2xPCIe x1 in hardware. Contact manufacturer to see if it’s possible. Another issue is that there is only one clock line, while Dual Edge TPU requires two and you’d need clock fanout driver IC, that’s why it’s “semi-passive”
Thanks for the information, i didn't know that. According to another thread the RK3399 doesn't support PCIe bifurcation so that option is off the table for me then. Still great work you're doing here, looking forward to the B+M Key Adapter becoming a real product.
If the B+M key 2280 adapter does indeed work with a PCIe to 4 x M.2 adapter (with a suitable CPU and motherboard that support bifurcation), then this seems like a perfect solution for me. 8 x Coral TPUs at a fraction of the cost of the Asus CRL-G18U-P3D would be ideal for my application. I know you have said the 1 x PCIe adapter is the first to go to production, any ideas when the B+M 2280 might be available?
If the B+M key 2280 adapter does indeed work with a PCIe to 4 x M.2 adapter (with a suitable CPU and motherboard that support bifurcation), then this seems like a perfect solution for me. 8 x Coral TPUs at a fraction of the cost of the Asus CRL-G18U-P3D would be ideal for my application. I know you have said the 1 x PCIe adapter is the first to go to production, any ideas when the B+M 2280 might be available?
@cdrose adapter shown here has tiny mistake that does not affect anything, but confuses when you know where to look at. I’d fix it and run small production run with availability around Christmas.
I would be keen to trial parts before Christmas, can you send me an email if you'd be open to discuss options for pushing things through a bit quicker.
I would be keen to trial parts too, I have two coral M.2 Accelerator with Dual Edge TPU boards I could run tests with
I, as well as some friends that i'll get to post here, are also interested in some of these B+M key 2280's. +2 at least.
Interested in 1-2, B+M 2280 for a Mini PC, Odyssey X86 Blue J4125, specifically to run frigate nvr
