[HN Gopher] Mini-ITX Seaberry Adds 11 PCIe Slots to a Raspberry Pi
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Mini-ITX Seaberry Adds 11 PCIe Slots to a Raspberry Pi
Author : geerlingguy
Score : 92 points
Date : 2021-11-24 15:05 UTC (7 hours ago)
(HTM) web link (www.jeffgeerling.com)
(TXT) w3m dump (www.jeffgeerling.com)
| tambourine_man wrote:
| I have no experience building PCs, but during the last decade or
| so I've been running RPis with 6-8 disks attached. It's great
| software and noise wise, but the cases were made by me with MDF
| (and I have no idea what I'm doing), so it's not as solid as I'd
| like them to be.
|
| Every time I search for rackmount or 3D printed cases I'm floored
| by the prices, which seem completely out of proportion.
|
| Any tips on cheep/custom computer cases are highly appreciated.
| Thanks
| rblatz wrote:
| It's probably easier to buy a regular case and then fit the
| raspberry pi into it.
| hinkley wrote:
| We should be meeting in the middle and creating SBCs whose
| bolt holes spacing is identical to some other device
| standard. For instance 2.5" HDDs, or 3.5-2.5 adapters. Then
| you can find trays and enclosures and caddies that can be
| modified slightly to purpose.
|
| Expanding holes in sheet metal is easy. Tapping holes,
| welding captive nuts, and bending are a lot trickier.
| sokoloff wrote:
| For something as lightly loaded as a home computer, rivnuts
| are pretty darn easy and cheap way to add threads to sheet
| metal.
|
| Brass standoffs with a nut on the back are also readily
| available and cheap.
| Ruthalas wrote:
| This would be excellent. That's a great idea.
| jrockway wrote:
| I agree with the advice that you should just use an ATX case.
| They are a commodity and there are a billion great ones. You'll
| have to remove the motherboard plate and drill 4 holes for M2.5
| standoffs; the full Raspberry Pi dimensions are on the product
| page, so you can easily print out a 1:1 template, get the right
| drill bit, and go. No fancy equipment is necessary to drill a
| small hole in sheet metal, and the result will be very
| satisfying.
|
| I tend to 3D print my own stuff, and have found it to be the be
| all and end all of electronics projects enclosures. I never had
| a good project enclosure until I got a 3D printer, and now I
| always have them. It's amazing! I have at least 3 different Pi
| projects, and I designed and printed cases for each of them.
| It's very straightforward and not a bad project for learning
| CAD and 3D printing.
|
| 8 hard drives are going to be heavy and take up a bunch of
| space, though, so that's why I'd recommend an off-the-shelf
| case that already has support for that. (Sheet metal bending is
| the right fabrication technique for this application, I think,
| and that's how the cases are made.)
| tambourine_man wrote:
| That's what I was afraid, you're convincing me of buying a 3D
| printer :)
|
| They are still a bit expensive, but are so much fun that they
| maybe worth it.
| dekhn wrote:
| I absolutely love laser-cut acrylic with tapped holes accepting
| m3 screws or standoffs.
|
| For the MDF, it's mostly practice and time/care. It took me
| quite some time to master making square wooden boxes that stand
| up to abuse and nowadays I could design in Fusion and rip out a
| case on my CNC machine pretty fast (<hours).
|
| Next project is to encase an entire RPi in clear epoxy:
| https://www.raspberrypi.com/news/epoxy-pi-resin-io/
| imachine1980_ wrote:
| its most a computer case(sound of drums) of production of
| scales the only ones who are mass produce are the ultra basic,
| the others are design for enthusiastic hobbyist who can pay a
| premium for their hobby.
| FpUser wrote:
| I am curious if by the time one finishes assembling all this
| stuff for Pi based IoT appliance the total cost (never mind time)
| will exceed one of some used laptop / small factor PC which can
| do the same thing but faster.
| bloopernova wrote:
| Please forgive my lack of familiarity with PCI express hardware,
| but I have a question:
|
| All those PCI express devices are all sharing the single v2 lane?
| Is the PCI express bus a network?
| dragontamer wrote:
| All I/O is a network these days.
|
| * USB is a network.
|
| * PCIe is a network.
|
| * SATA is a network.
|
| * Infinity Fabric / Hypertransport (AMD socket-to-socket
| communications) is a network.
|
| * UltraPath Interconnect (Intel socket-to-socket
| communications) is a network.
|
| -----------
|
| People think their internet connection is Layer4 (TCP) ->
| Layer3 (IP) -> Layer2 (Ethernet) -> Layer1 (Wires), but that's
| wrong.
|
| Its really Layer4 (TCP) -> Layer3 (IP) -> Layer2 (Ethernet) ->
| Layer 3 (PCIe) -> Layer 2 (PCIe frames) -> Layer 1 (PCIe wires)
| -> reinterpret PCIe on the Ethernet-controller -> Layer1
| (Ethernet wires).
|
| There's a bunch of "networks" in-between our networks that we
| use. That's why OSI model exists, to understand each different
| network and each of the different rules behind them all.
|
| When a good network is abstracted away, you can ignore all the
| details.
|
| EDIT: It might not even be Layer2(Ethernet) -> Layer3 (PCIe)...
| on a NUMA-system it could be Layer2(Ethernet) -> Layer2 (NUMA /
| MESI messages to CPU#2) -> Layer2 (Southbridge communications)
| -> Layer3(PCIe)...
| agumonkey wrote:
| network all the way down
|
| -- Alan Kay maybe
|
| btw, slight sidestep HDMI CEC is also a bus/network, and even
| SCART was too.
| geerlingguy wrote:
| Indeed, PCI Express can be thought of in many ways like
| Ethernet; you can have switches just like Ethernet, though in
| almost all cases, PCIe is a local area bus (local to one
| server/machine), whereas Ethernet is still the king of
| networks.
| colejohnson66 wrote:
| One of the goals of PCIe when they were designing it was to
| avoid the "bus" architecture classic PCI had as that forced
| every device on the bus to run at the speed of the slowest
| device. PCIe, OTOH, takes a "star" network topology (more a
| "tree" though) with point to point connections. Thanks to the
| use of switches, each point can run at the maximum speed they
| support (limited by the switches speed).
|
| Basically, it's like USB (as @dragontamer said). Just as you
| can turn a single USB port into 7 more downstream ports through
| a USB switch, you can do the same with a PCIe switch.
| NovemberWhiskey wrote:
| That's probably the way to think about it. PCIe devices
| communicate point-to-point over dual-simplex serial
| connections. If you have something like a Raspberry Pi CM4,
| which only has a single PCIe lane, then there's going to be a
| PCIe switch.
| bloopernova wrote:
| Interesting, thank you!
| Teknoman117 wrote:
| The other neat thing is that peer-to-peer PCIe transactions
| do not have to go through the root complex (the Pi in this
| case).
|
| Say you have a GPU and an NVMe drive or video capture card
| plugged into a PCIe switch, which is then plugged into the
| Pi. If your software supports having these devices directly
| communicate, they can do so as fast as their PCIe links
| support doing, even though there's only the tiny link to
| the Pi.
|
| Peer-to-peer transfers are only limited by the smallest
| link on the path between two devices on the tree, rather
| than the smallest link in the tree.
|
| A real world example is some of the big GPU compute
| servers. Some of the 4U chassis can house 20 or more cards.
| Many of them have all of the GPUs (320 or more PCIe lanes)
| plugged into an array of PCIe switches which may constrain
| them to 16 or 32 lanes from the CPU. The GPUs can all talk
| to each other a full speed, but only a few can go full
| speed to the CPU at a time.
| salawat wrote:
| Don't you mean the CPU can only full-duplex with a few
| GPU's at a time?
|
| And are you sure that GPU's are actually talking with
| each other?
|
| Forgive me if I'm woefully out of date/having a massive
| brainfart, but last I heard, GPU's got CPU-less DMA a few
| years ago allowing access to system memory, but
| programming/setting up the
| pipelines/cleanup/repriming/output consolidation was
| still solely a CPU-centric work stream.
|
| So like, yeah, your GPU does it's thing and dumps the
| result in a buffer in it's memory space, and might even
| be smart enough to shlup a buffer back to system RAM to
| get the result forwarded somewhere else when the CPU gets
| around to telling the storage controller to do it...
|
| But did I completely sleep through something absolutely
| amazing? Are GPU's passing messages/shared memory space
| aware now? Like,
|
| "Oh, my jobs done, shlup this buffer off to pcie
| device->compute_card_2 for the next stage of processing."
|
| Because if they're that smart now, holy crap, I have
| reading to do.
| Teknoman117 wrote:
| Yes, GPUs are able to directly pass messages and bulk
| data to each other these days. It's completely supported
| in CUDA, OpenCL, Vulkan, DirectX 12, etc. DirectX calls
| it "Explicit Multi GPU".
|
| It's been around since GPUs transitioned to PCIe, it's
| just that both AMD and NVIDIA just locked it to the
| "professional" GPUs, or only used it under the hood of
| some other feature. AMD GPUs have used PCIe peer to peer
| copies for CrossFireX since the GCN Radeon GPUs (R9 290X
| and friends), that's why they don't need an external
| bridge.
|
| There's DirectGMA (AMD) and GPUDirect (NVIDIA) which
| allows PCIe drivers for other devices to directly copy to
| and from GPU VRAM.
|
| Other than driver support, nothing prevents PCs from
| having GPUs communicate directly with storage devices.
| The GPU would need to expose some of it's VRAM over PCIe
| (using a BAR window). The OS and the GPU driver would
| need to create some NVMe submission and completion queues
| either in system or VRAM that the GPU can be considered
| to own. You'd then issue NVMe operations where the
| backing pages point into the VRAM. The resizable bar
| support of the current Radeon and GeForce GPUs is a major
| step in this direction, although again, resizable bars
| were part of the original PCIe specification and has been
| available on server hardware since ~2008.
| geerlingguy wrote:
| The 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.
| otachack wrote:
| Always enjoy the blog/video posts you do, Jeff. Thanks for
| creating this awesome, in-depth content!
| _joel wrote:
| Seconded, I'm envious of your new NAS though :)
| mrtweetyhack wrote:
| Damn, I needed 12
| ChristianGeek wrote:
| Once you get to this size and price, there's no point in using a
| Pi...there are much more powerful options available.
| jeroenhd wrote:
| I can see someone making a very powerful open source WiFi
| router out of this. The Pi can run passively cooled unlike most
| Intel or AMD CPUs. You wouldn't be doing any DPI on the network
| traffic without slowing things down, but this thing with some
| networking hardware cards could become very interesting to many
| people.
|
| The cost is too high because it's a niche product, of course,
| but such a board would be able to replace my home router/server
| quite capably with a good WiFi antenna and some ethernet ports.
| timc3 wrote:
| There are other platforms that are maybe better suited to
| that role though. I am not very up to date with the hardware
| but I remember PCengines being one.
| NovemberWhiskey wrote:
| How many networking cards? I know we tend to think of
| internal buses as infinitely-fast, but a single PCIe 2.x lane
| is saturated at 500MB/s, which begins to look a little skinny
| once we're considering 10GE or even Wifi 6.
| CameronNemo wrote:
| A single NVMe drive will saturate that.
| geerlingguy wrote:
| Indeed, the maximum bandwidth I've gotten out of anything
| is around 420 MB/sec from a single NVMe drive. Add in
| more devices and you basically divide the bandwidth
| proportionally. Round trips can even slow things down a
| bit more.
| opencl wrote:
| A 4 lane PCIe switch would allow for a much cheaper board and
| still be plenty to saturate the available bandwidth. Maybe 2x
| 2.5Gbe with one hooked to a switch, plus wifi.
|
| Around this price point there are already ARM boards (and
| passively cooled x86 machines) available much better suited
| to this kind of use case, like the Honeycomb LX2K.
| wongarsu wrote:
| 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.
| bserge wrote:
| > Or just buy a used PC.
|
| And miss out on doing my part in destroying the environment?
| I don't think so, bud!
|
| I buy new everything. New phone, new computer, new car, new
| shoes every year. You think I reside in a developed country
| to live like some African? Bruh.
|
| If you don't throw out your whole PC whenever it slows down
| due to dust accumulated on the heatsinks, you should go live
| in rural China.
|
| I pay lip service to the "green" shit by buying electric cars
| and LEDs... Ford trucks and 50W lamps, that is.
|
| I keep my windows open in winter because I have a damn
| efficient heat pump, too. My fridge has no doors.
|
| Don't be a Midlands faggot, live like a king.
| mikepurvis wrote:
| For the sub-$100 price point, you often can't beat discarded
| thin clients. There's a steady of stream of units always
| hitting eBay, including ARM ones like the HP T-series and x86
| ones like Dell Wyse units.
|
| If you really just need something that comes with a case and
| power supply, might already have wifi, and has a few USB2
| ports to plug things into, these are great options.
| geerlingguy wrote:
| 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.
| zw123456 wrote:
| Some friends and co-workers of mine have an ongoing bet/joke...
| Who can find something that the Raspberry Pi can NOT do.
|
| One more thing scratched off the list!!
| 542458 wrote:
| Boot without a GPU - Pi can't do that :)
| zw123456 wrote:
| Good one. Putting it on the list.
|
| It's an amazing little board, list is pretty short :)
| sandreas wrote:
| Things that are on my wishlist:
|
| - Compute-Module should have a unified interface, that is not
| about to change for the next 3 generations of compute modules
|
| - Someone create a "notebook" case having a board with mount for
| exactly this interface
|
| - Case should have a decent keyboard and display without being to
| big
|
| - How about having GPIO pins hidden
|
| I would love to have an "upgradable" Notebook with arm
| architecture...
| cjbconnor wrote:
| Have you seen the MNT Reform? There's a pi compute module
| adapter being built for it.
| sandreas wrote:
| Yeah, quite bulky :-) But interesting approach.
| nine_k wrote:
| If you want a _fast_ laptop, your two priorities are, IMHO, the
| thermal design and making as much room as possible for the
| battery.
|
| I'm afraid that RPi level of performance in a laptop is going
| to be underwhelming, though still interesting for many cases.
|
| If there was a widely accepted standard for laptop main boards,
| like there is for desktop and server boards, that would be
| wonderful. I don't expect it to ever happen though.
| rektide wrote:
| Alas 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-...
|
| [2] https://www.mouser.com/c/?marcom=100722352
| MisterTea wrote:
| > 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.
|
| Its not up to Arm to attach PCIe lanes but the chip makers who
| have been competing with x86 which already offer plenty of PCIe
| lanes. So far, only apple has bothered to make an Arm CPU which
| can compete with "PC" hardware. Hopefully AMD will offer
| something similar.
|
| > 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.
|
| USB4 is based on Thunderbolt 3. Given that Thunderbolt 3 is a
| mess, I don't have high hopes.
|
| Look at RapidIO or 1394 for examples of better thought out
| interconnects and protocols. PCIe cant connect CPU's together
| in a NUMA system whereas RapiIO can. RapidIO also uses Ethernet
| physical layers so there's parallel development with Ethernet.
| I honestly don't like USB or contraptions invented by Intel
| that are invariably consumer grade with various extensions to
| satisfy other industries, bolted on.
| rektide wrote:
| i thought it was pretty clear i meant the consumer arm
| ecosystem in general but thanks for chiming in & clarifying.
| yup.
|
| usb4's ability to transport a variety of protocols across the
| switched network seems perfect. reviews like the Plugable tb4
| hub show video and data intermixing nicely[1]. the complexity
| seems scary but in my mind it feels utterly & completely
| justified, and it builds atop the world we have & makes it
| better, quietly fixes the underpinnings, rather than
| insisting on re-invention. thunderbolt hasn't been flawless
| but it's been a niche product, a luxury product, and we'll
| quickly gain the experience to make it as pleasant
| bulletproof & flawless as one might hope for. already,
| reviews like the one i cited don't come with caveats or speed
| bumps: they show a working, satisfying consumer experience.
| there's a lot of afraidness of thunderbolt & usb4, but i for
| one think we ought to dial down our resistances & afraidness.
|
| that said, i also think the door is totally open to new
| interconnects emerging. i'd love to see cxl or gen-z
| (recently folded into cxl) or opencapi or rapidio or whatever
| become consumerized.
|
| [1] https://www.anandtech.com/show/16964/plugable-
| tbt4hub3c-thun...
| NovemberWhiskey wrote:
| >So far, only apple has bothered to make an Arm CPU which can
| compete with "PC" hardware.
|
| Also Amazon: https://aws.amazon.com/ec2/graviton/
| MisterTea wrote:
| Those are server processors, I was thinking more along the
| lines of laptop/desktop performance. Other examples of Arm
| server CPU's are from Ampere and AMD's discontinued Opteron
| A series.
| scottlamb wrote:
| > 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.
|
| In the shorter term, I'm hoping the RK3588 actually comes out,
| is as good as promised, and has a reasonable price. [1] 4 lanes
| of PCIe 3.0 + 3 lanes of PCIe 2.0 + 2x USB 3.1 + dual gigabit
| Ethernet total at well over 10X the bandwidth of the Pi's
| single PCIe 2.0 lane. Also things I care about for my NVR
| project: faster video decoding, built-in TPU, and SATA (which I
| didn't count above because it's multiplexed with the PCIe 2.0).
|
| I don't think the 4x Cortex-A76 + 4x Cortex-A55 is in the same
| league as the Apple M1, but still quite a bit faster than the
| Pi4's 4x Cortex-A72.
|
| [1] https://www.cnx-software.com/2020/11/26/rockchip-
| rk3588-spec...
| CameronNemo wrote:
| _I don 't think the 4x Cortex-A76 + 4x Cortex-A55 is in the
| same league as the Apple M1, but still quite a bit faster
| than the Pi4's 4x Cortex-A72._
|
| IMO the node used is more important than the core design.
| Rockchip claims they will be using an 8nm node for the
| rk3588. And I think the rk3399 and Pi4 are using 28nm nodes
| right now. So if this chip materializes it could be much
| faster (compared to Linux oriented ARM boards of today).
| fnord77 wrote:
| sorry if this is obvious, but how many CM4s can you plug into
| this board?
| geerlingguy wrote:
| One. Don't worry though, next week I'll be covering the Turing
| Pi 2...
| marcodiego wrote:
| Recent 4-cores, 2.0+ Ghz and 4GB RAM ARM SBC's are plenty
| powerful for most tasks a home user may need. Media consumption,
| browsing, light text editing, editing the weekend video and even
| compiling small code bases. People have been doing that in
| chromebooks for years.
|
| Unless you need to compile large code bases, edit serious videos,
| process huge amounts of data or CAD/games, a simple cheap ARM
| computer should be enough.
|
| Too bad the desktop was taken by a monopoly and monoculture of
| x86-64 with windows where you are locked if you need
| compatibility with some proprietary formats or tools/software.
| alias_neo wrote:
| I wonder if there is a blog post in this somewhere, that I
| could write.
|
| I have a bunch of Pi 4s (4GB). I just put one in an Argon M.2
| case and was wondering what to do with it.
|
| I have a "gut feel" for how my workstation should behave, I am
| a (backend) software engineer by profession, tend to work my
| day job on an i7 laptop (XPS 15, Ubuntu) but at home I'm on
| Ryzen 7 1800X (Manjaro) and Ryzen 9 3900X (Debian).
|
| Is there some useful non-benchmark type "measurements" I could
| take by using a Pi as a workstation for a few days, that people
| would be interested to read about?
| 3np wrote:
| One significant bottleneck in a common desktop Rpi would be
| the SD card. You can improve a lot by putting the root
| filesystem on SATA-over-USB or use the CM with an appropriate
| board.
|
| If you'd have been in the market for a new board, I would
| have recommended something that exposes PCIe, or at least
| SATA.
|
| The best non-SoM option < USD 100 for that is probably RockPi
| 4 (but please fill in). You can fit it with an M2 NVMe (with
| limited lanes) or multiple SATA drives. RK3399 or RK3399pro
| have been holding that segment for some time now. Sadly
| RK3399 has max 4GB RAM. Armbian works great.
|
| There is also Quartz64 and Rock 3A (max 8GB RAM, PCIe3). But
| it's going to take a while until community and mainline
| kernel support make the RK3566/RK3568 ready for a casual
| user.
|
| You're going to have to be conscious about multitasking.
| Having 100 browser tabs open is not going to fly. And while
| 4k may be theoretically possible, you don't want to do that.
| Other than that I think it's all right.
|
| -----
|
| I have a similar profile to yourself. Currently drafting a
| small cyberdeck - maybe more as a replacement for smartphone
| than PC use.
| CameronNemo wrote:
| _But it 's going to take a while until community and
| mainline kernel support make the RK3566/RK3568 ready for a
| casual user._
|
| https://wiki.pine64.org/wiki/Quartz64_Development#Upstreami
| n...
|
| TL;DR
|
| Video output just recently (this week) got ported to
| mainline Linux, but it is still a bit rough. Only works on
| 1080p60fps monitors.
|
| Everything else major for the kernel has been mainlined or
| is in review.
|
| U-boot is still only downstream rockchip with closed source
| memory initialization (boot blobs).
| marcodiego wrote:
| You can try subjective benchmarks. These ARM SBC's are as
| powerful as workstations from the 90's, so try to use them
| with as demanding software as what was run on a workstation
| from the 90's.
|
| Trying to replicate this would certainly do a great blog
| post: https://news.ycombinator.com/item?id=27796821
| 3np wrote:
| It's comparable to a brand new Intel workstation in 2010.
|
| https://www.cpubenchmark.net/compare/Rockchip-RK3399-vs-
| Inte...
|
| For most people trying this, the SD card is the bottleneck
| and there are options. The mentioned Rpi2 had USB 2.0
| shared with storage and network. The 4B has USB 3.0 and
| dedicated lanes for GBE and storage.
|
| Ryzen 3700 <> RPi 4B <> RPi 2
| [deleted]
| h2odragon wrote:
| We'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)
| dragontamer wrote:
| I'm pretty sure PCIe is that today.
|
| PCIe CPUs may have failed commercially, but they prove that its
| possible (Xeon Phi).
|
| PCIe GPUs are common. 4x or 8x GPUs are your typical mining
| rigs.
|
| Perhaps most common is PCIe SSDs (aka: NVMe or M.2 slots).
|
| ------
|
| So our modern PCIe "backplane" gives us storage, extra compute
| (GPUs most commonly), longer-distance network access (fiber
| optics, ethernet, etc. etc.). What else do you want?
|
| Sound cards (especially MIDI instruments support) maybe?
| Dedicated video processors? A big problem with dedicated
| devices is that modern CPUs are so powerful... there's not much
| point to buying an ElGato H264 encoder anymore when you can
| just buy a 16-core CPU instead and do it all in software.
|
| ----
|
| Your standard Threadripper motherboard has 4x16 PCIe slots, and
| I'm pretty sure 8x PCIe to each of the slots, with full support
| of bifurcation (splitting into smaller PCIe slots). Surely
| that's enough for any of your hobby projects?
| h2odragon wrote:
| What got me off about VME when i looked at it was the immense
| amount of small market, single purpose hardware that had been
| thrown on it and was "technically" compatible. It enabled
| some stuff like timed traffic lights in a way similar to how
| Arduinos have opened up hobby level "printer-oid" mechanisms.
|
| For reasons i cant articulate well I'm itching for a bus
| where CPU and GPU and RAM and IO all live together in hippie
| harmony. The hardware's all there and dancing to some little
| basic machine controller CPU anyway so lets open all that up
| and make everything a first class citizen, hopefully on some
| interconnect that will last a few years and gather some
| interesting surplus hardware to filter out to hackers.
|
| As to modern hardware, if i had all my dreams coming true,
| I'd be grabbing one of the "mining" motherboards with all
| that I/O broken out into channels and putting SDR's on them
| to make pretty waterfalls of the biggest bites of the radio
| spectrum i could visualize.
| dragontamer wrote:
| For hobby Arduino level, the bus of note is I2C, with all
| sorts of devices available. Temperature sensors,
| accelerometers, cameras, monitor control, flash, ram and of
| course... other arduinos and Rasp Pis.
|
| Of course, 1Mbit is slow but the huge amount of
| compatibility is pretty outstanding.
|
| ----------
|
| Today's standard I/O might be Ethernet, as far as just
| randomly hooking up random compute devices together.
|
| Faster than I2C, but not quite PCIe speeds. You can't deny
| the huge compatibility available though.
|
| ------
|
| PCIe is for serious business high end. A few commodity
| parts are available but some stuff is just really
| expensive. It's a professional tool for high end fabrics.
|
| The best of the best remains proprietary: Infinity Fabric,
| UPI. I guess OpenCAPI isn't technically proprietary but few
| things use that...
|
| -----
|
| I know there are a bunch of cuda-SDR projects btw. I don't
| know how well they work but GPUs probably are great at
| Fourier Transforms and other filtering tasks.
| martin8412 wrote:
| I2C is present in most modern computers. Look up SMBus.
|
| SPI is as well
| tjoff wrote:
| VME?
| h2odragon wrote:
| https://en.wikipedia.org/wiki/VMEbus
|
| see also https://en.wikipedia.org/wiki/Sun-4
| myself248 wrote:
| https://en.wikipedia.org/wiki/VMEbus
|
| Imagine something like ISA but 32 bits wide, with a GPIB-like
| arbitration scheme. On a backplane that you plug CPU cards
| and peripheral cards into.
| exabrial wrote:
| Is there a storage controller like a SAN that can do provisioned
| NVMe?
|
| Something like you insert a RPI into a backplane, and it auto-
| provisions some storage and makes it available to the RPI, in
| addition to providing power/ethernet.
| ed25519FUUU wrote:
| Does this make building a large NAS with an RPI doable?
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