Mini-ITX Seaberry Adds 11 PCIe Slots to a Raspberry Pi
jeffgeerling.com
Mini-ITX Seaberry Adds 11 PCIe Slots to a Raspberry Pi
1–10 of 74 posts
Re: Mini-ITX Seaberry Adds 11 PCIe Slots to a Raspberry Pi
#2We're like one or two hardware generations away from having a VME backplane like environment where we'll be able to do some truly nifty and nasty things, at home and hobby levels.
The politics of getting a standard out that isn't owned by (and therefore twisted to favor) a couple of big companies is challenging, but it's happened before, right? (crickets)
Re: Mini-ITX Seaberry Adds 11 PCIe Slots to a Raspberry Pi
#3The tl;dr is it's a standard mini ITX-sized motherboard for the Raspberry Pi Compute Module 4. It has a Broadcom PCIe switch that it uses to power 4 mini PCIe slots, 4 M.2 E-key slots, 1 M.2 M-key slot, a x16 slot in the standard ITX location, and an edge x1 slot. It also has dual/triple-redundant 12v power supplies (barrel, aux +/- ATX, and PoE++ header, though it doesn't use a 24-pin ATX connector, so you need to power it with an adapter or via wall wart (I used a 96W barrel plug adapter).
Through the course of testing this thing, I also identified a bug in the PWM fan controller circuit—and apparently it's also a small bug present on the CM4 IO Board's implementation, but typically not a fatal one.
Re: Mini-ITX Seaberry Adds 11 PCIe Slots to a Raspberry Pi
#4Once you get to this size and price, there’s no point in using a Pi…there are much more powerful options available.
Re: Mini-ITX Seaberry Adds 11 PCIe Slots to a Raspberry Pi
#5Alas PCIe switches were starting to get affordable before the great chipmaker consolidation of 2015-2019 ("and seemingly overnight the cost of these switches increased three-fold"[1]). Now most every PCIe switch is >$6/lane. Even just the 12 lanes here, on an old PCIe generation, is going to be a $72 chip, perhaps more (article: PEX8619 Broadcom PCIe switch, $129, 16 lanes, $8/lane, no stock. Compare versus Microchip nee PMC-Sierra Switchtec such as PM40028B1 at $6/lane[2]).
It's a cool idea. But wow, for $435, sure feels one ought consider going for an x86 pc. The form factor is cool though.
It feels insane to hope for but I'm really hoping that by the time 2025 rolls around we see some modest affordable arm chips that have Thunderbolt built in. Perhaps even multiple Thunderbolt. If nothing else, there better be some decent PCIe available by then- 8x PCIe 5.0 or better. ARM needs to start doing bandwidth, some day (in places other than server class chips); it's been on USB3.0 for a long long time. Thunderbolt + PCIe would be a great boon for general usability & connectivity. Now that Intel has made it royalty free, now that USB4 already incorporates most of the hard part (packet based switching), it might finally be the time for some real PCIe on chip.
[1] https://www.anandtech.com/show/15821/microchips-new-pcie-40-...
Re: Mini-ITX Seaberry Adds 11 PCIe Slots to a Raspberry Pi
#6[deleted]
Re: Mini-ITX Seaberry Adds 11 PCIe Slots to a Raspberry Pi
#7The tl;dr is it's a standard mini ITX-sized motherboard for the Raspberry Pi Compute Module 4. It has a Broadcom PCIe switch that it uses to power 4 mini PCIe slots, 4 M.2 E-key slots, 1 M.2 M-key slot, a x16 slot in the standard ITX location, and an edge x1 slot. It also has dual/triple-redundant 12v power supplies (barrel, aux +/- ATX, and PoE++ header, though it doesn't use a 24-pin ATX connector, so you need to p…
Always enjoy the blog/video posts you do, Jeff. Thanks for creating this awesome, in-depth content!
Re: Mini-ITX Seaberry Adds 11 PCIe Slots to a Raspberry Pi
#8Once you get to this size and price, there’s no point in using a Pi…there are much more powerful options available.
I guess it makes sense as a development board: if you are building a product around a Pi Compute Module you can use this board for quick prototyping before building your own product-specific board. But any hobbyist looking at this should seriously consider the various Pi alternatives around the $200 mark first. Or just buy a used PC.
Re: Mini-ITX Seaberry Adds 11 PCIe Slots to a Raspberry Pi
#9Once you get to this size and price, there’s no point in using a Pi…there are much more powerful options available.
I guess it makes sense as a development board: if you are building a product around a Pi Compute Module you can use this board for quick prototyping before building your own product-specific board. But any hobbyist looking at this should seriously consider the various Pi alternatives around the $200 mark first. Or just buy a used PC.
This is spot on. I mention in the post and the video it's an expensive board, and very specialist.
The target audience is basically 'person who wants ARM64 PCI Express development board', and even there, some of the PCI Express implementation on the Pi's BCM2711 is... weird. Therefore some devices have had a hard time getting drivers going on the Pi (case in point: graphics cards and Coral TPUs I've tested). I plan on testing Radxa's CM3 and Pine64's SOQuartz too.
I think some people still want a cheap(ish) CM4 motherboard that just has one x16 slot, front panel headers, and maybe a 24-pin ATX power supply connector. I think that could be made for under $100 and would also solve a lot of needs for debugging purposes.
Re: Mini-ITX Seaberry Adds 11 PCIe Slots to a Raspberry Pi
#10The tl;dr is it's a standard mini ITX-sized motherboard for the Raspberry Pi Compute Module 4. It has a Broadcom PCIe switch that it uses to power 4 mini PCIe slots, 4 M.2 E-key slots, 1 M.2 M-key slot, a x16 slot in the standard ITX location, and an edge x1 slot. It also has dual/triple-redundant 12v power supplies (barrel, aux +/- ATX, and PoE++ header, though it doesn't use a 24-pin ATX connector, so you need to p…
Always enjoy the blog/video posts you do, Jeff. Thanks for creating this awesome, in-depth content!
Seconded, I'm envious of your new NAS though :)