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PCI Express on the Raspberry Pi 4

mloduchowski.com

31–40 of 166 posts

Re: PCI Express on the Raspberry Pi 4

#31
post #23
post #20

Earlier quoted context omitted.

True. And with RPi4 having a 1000baseT, it’s not as painful as it seems. Perhaps even the driver can be coaxed into some form of DMA and MPI that is a bit lower latency than IP stack. With secondary IP layer on 802.11, it might actually work reasonably well.

Or use the PCIe mod and use an infiniband card for low latency and high thoughput.

At that price point, you could probably get more performance out of a server with 2-4 sockets.

Re: PCI Express on the Raspberry Pi 4

#32
Now this is the content I come to HN for. A serious hack just days after the 4 was released. Kudos to the OP.

I envy people like OP for their tenacity. I barely have time to follow what's happening in IT, much less get ahead of the pack in doing cools hacks like this.

Re: PCI Express on the Raspberry Pi 4

#33
Ohh I see where this is going qdot_me — would love to be able to hook up a GPU to a RPi4 to crypto-mine. So useful for so many applications ! I will seriously fund you if you can make this happen, hit me up by email. My contact info is on zorinaq.com

Re: PCI Express on the Raspberry Pi 4

#34
Hijacking the thread:

I develop remotely on VPSes because I like to have an always-on box reachable from any client. I am wondering if a RP4 offers a similar experience at lower cost.

Does anyone use a RP for this?

Re: PCI Express on the Raspberry Pi 4

#35
post #34

Hijacking the thread: I develop remotely on VPSes because I like to have an always-on box reachable from any client. I am wondering if a RP4 offers a similar experience at lower cost. Does anyone use a RP for this?

I do this with an RPi3 and it's doing good, so it's doable. It strongly depends on your setup and develeopment environment, though. Do you want VI to work over SSH or want full VNC access to a machine with Gnome and Eclipse? Or something in between like X forwarding? Also, is aarch64 even an option as a host system? (compilations, software availability etc.)

Re: PCI Express on the Raspberry Pi 4

#36
post #9

Earlier quoted context omitted.

Wouldn't the gigabit LAN be a better fit for this? If you want to make a cluster, you need to make some custom hardware to connect to, that can facilitate the communication. At this point you're likely spending more that if you just bought a real desktop for more performance. I can see the fun factor in hacking the system together, though.

There are two ways of doing clusters - one is a message passing paradigm, which you can do over Ethernet (to an extent - I’d still take USB3 for 4x the bandwidth) - and the other is direct memory access a’la Cray. What really motivated me to do this hack is the relative abundance of stuff I can now plug into an FPGA :)

There's also InfiniBand which can reach much greater bandwidths.

Re: PCI Express on the Raspberry Pi 4

#37
post #34

Hijacking the thread: I develop remotely on VPSes because I like to have an always-on box reachable from any client. I am wondering if a RP4 offers a similar experience at lower cost. Does anyone use a RP for this?

I do this with an RPi3 and it's doing good, so it's doable. It strongly depends on your setup and develeopment environment, though. Do you want VI to work over SSH or want full VNC access to a machine with Gnome and Eclipse? Or something in between like X forwarding? Also, is aarch64 even an option as a host system? (compilations, software availability etc.)

I use tmux and vim over ssh. You mean Arch? Yeah why not.

Then also a lot webpack, Docker: wondering if they would get the Pi stuttering when compiling/building? And if vim is still smooth then (which isn't the case with my 20$ vps).

Re: PCI Express on the Raspberry Pi 4

#38
post #6
post #2

That's really cool. I'm curious, would it be possible to use a modern GPU (running at 1x) on an ARM based board? Would the open source drivers that are part of the Kernel work out the box on ARM?

Hack’s creator here - it’s on my list of things to try. GPUs are notoriously hard to get to work on non-intel, having tried to get a few up on Alpha and Itaniums in the past. VideoBIOS expects to run and expects a well behaving Intel CPU to do the power-up. That said X can sometimes emulate these quite well. On ARM we’d also run into alignment issues and likely other quirks - but in principle...

Some AMD cards have an Arm build of their UEFI firmware available, which does allow video from boot: https://developer.arm.com/architectures/system-architectures...

Re: PCI Express on the Raspberry Pi 4

#40
post #37

Earlier quoted context omitted.

I do this with an RPi3 and it's doing good, so it's doable. It strongly depends on your setup and develeopment environment, though. Do you want VI to work over SSH or want full VNC access to a machine with Gnome and Eclipse? Or something in between like X forwarding? Also, is aarch64 even an option as a host system? (compilations, software availability etc.)

I use tmux and vim over ssh. You mean Arch? Yeah why not. Then also a lot webpack, Docker: wondering if they would get the Pi stuttering when compiling/building? And if vim is still smooth then (which isn't the case with my 20$ vps).

AArch64 is what the 64-bit version of the ARM instruction set is called.
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