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64 bit OS Raspberry Pi4 Benchmarks

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Re: 64 bit OS Raspberry Pi4 Benchmarks

#21

One of the things that I find great about Raspbian is that the boot files are stored on a FAT32 partition which is readable from any OS, and there are some nice considerations for headless setups: drop in a wpa_supplicant.conf to configure Wi-Fi, `touch ssh` to get OpenSSH enabled at next boot. Do any of the alternative OSes, like Ubuntu, offer this?

So that's how they came up with that. As someone who normally installs "normal" Linux systems I find it quite irritating that you have to put a file somewhere, especially the boot record, to "enable" ssh of all things. Up until now I considered it a weird decision. (and I still think it is not optimal) I deploy my RPi's in the field and don't put a monitor on them so I would expect ssh running as default. First time I found out about it was when reading the unit file when I was building a custom image based on raspbian, so I wouldn't consider it obvious :) When working on a Linux Device I just mount the main partition and do my customizations.

Re: 64 bit OS Raspberry Pi4 Benchmarks

#22

what would be ideal for raspi 3 and up are aarch64 binaries with a 32 bit memory model (aarch64-ilp32). Dies debian support/use this?

As far as I'm aware, ilp32 support for aarch64 has been proposed and implemented, but the patches weren't accepted upstream in the kernel because nobody was able to make a sufficiently convincing case that there was enough benefit to justify adding a whole new ABI to the kernel (there are a few benchmarks where it's noticeable but mostly it just doesn't make enough difference to be worthwhile, AIUI). Possibly the situation has changed since I last heard about it.

Re: 64 bit OS Raspberry Pi4 Benchmarks

#23

Has anyone gotten the aarch64 Raspberry Pi image of Alpine to work on the Pi 4? It seems like a good fit for a RAM constrained system but I could never get it past the colorful boot screen.

It's fairly easy to trim down what runs on Raspbian. so if your only concern is background tasks eating RAM, you don't need something like Alpine to fix that issue. We use Pis at my work for running slideshows, and while performing their duty they use about 123MB of RAM for all running software (mostly our software + monitoring tools).

Raspbian doesn't offer aarch64 userspace though.

Re: 64 bit OS Raspberry Pi4 Benchmarks

#24
post #17

Earlier quoted context omitted.

The flipside is-- if you have a 1GB pi, you're going to be wasting a whole lot of RAM on wider pointers, and you may be more constrained by RAM than CPU throughput. (Also, 64 bit Pi is not nearly as well supported as 32 bit currently. Does hardware GL work yet? What about if you're going to do MIPI, etc?) IMO it's worth waiting for a little more maturity.

Has nobody tried to implement an aarch64 equivalent of the "x32" ABI? That is, using the 64-bit instruction set but keeping pointers 32 bits long?

There's Arm64ilp32, but I don't think it's in the mainline kernel and it's really bleeding edge/strange.

When aarch64 is so badly supported on pi, it's really scary to go even further into the fringe with Arm64ilp32.

Re: 64 bit OS Raspberry Pi4 Benchmarks

#25

Has anyone gotten the aarch64 Raspberry Pi image of Alpine to work on the Pi 4? It seems like a good fit for a RAM constrained system but I could never get it past the colorful boot screen.

Yes. All 9 of my rpi4 systems run the aarch64 image. I some issues with 3.11.0 but 3.11.3 should work pretty well now.

Re: 64 bit OS Raspberry Pi4 Benchmarks

#26
One downside: you will probably need a bit more memory to do the same work. An unmentioned benefit: better ASLR, for what that's worth.

> A 64 bit system means that RAM can be accessed in 8 byte read/writes per instruction.

I mean...kind of but that's probably not really what's happening in this benchmark. Firstly, in that test `memset()` is surely using NEON instructions internally on both ARMv7 and AArch64, which can load/store up to 32 bytes in a single instruction. Further that test is really just showing the bandwidth of the memory controller. I'm not sure why AArch64 would matter there. It's possible that `memset` / `memcmp` are using smarter prefetching instructions in AArch64.

Re: 64 bit OS Raspberry Pi4 Benchmarks

#27

One of the things that I find great about Raspbian is that the boot files are stored on a FAT32 partition which is readable from any OS, and there are some nice considerations for headless setups: drop in a wpa_supplicant.conf to configure Wi-Fi, `touch ssh` to get OpenSSH enabled at next boot. Do any of the alternative OSes, like Ubuntu, offer this?

So that's how they came up with that. As someone who normally installs "normal" Linux systems I find it quite irritating that you have to put a file somewhere, especially the boot record, to "enable" ssh of all things. Up until now I considered it a weird decision. (and I still think it is not optimal) I deploy my RPi's in the field and don't put a monitor on them so I would expect ssh running as default. First time…

> I deploy my RPi's in the field and don't put a monitor on them so I would expect ssh running as default. First time I found out about it was when reading the unit file...

So I guess you weren't building those images? If you're building headless RPi images that's something you learn immediately.

Re: 64 bit OS Raspberry Pi4 Benchmarks

#28

One of the things that I find great about Raspbian is that the boot files are stored on a FAT32 partition which is readable from any OS, and there are some nice considerations for headless setups: drop in a wpa_supplicant.conf to configure Wi-Fi, `touch ssh` to get OpenSSH enabled at next boot. Do any of the alternative OSes, like Ubuntu, offer this?

So that's how they came up with that. As someone who normally installs "normal" Linux systems I find it quite irritating that you have to put a file somewhere, especially the boot record, to "enable" ssh of all things. Up until now I considered it a weird decision. (and I still think it is not optimal) I deploy my RPi's in the field and don't put a monitor on them so I would expect ssh running as default. First time…

Raspbian did originally come with SSH enabled by default but the default credentials pi/raspberry made it trivial for misuse: https://www.zdnet.com/article/linux-malware-enslaves-raspber...

Re: 64 bit OS Raspberry Pi4 Benchmarks

#29

Earlier quoted context omitted.

So that's how they came up with that. As someone who normally installs "normal" Linux systems I find it quite irritating that you have to put a file somewhere, especially the boot record, to "enable" ssh of all things. Up until now I considered it a weird decision. (and I still think it is not optimal) I deploy my RPi's in the field and don't put a monitor on them so I would expect ssh running as default. First time…

> I deploy my RPi's in the field and don't put a monitor on them so I would expect ssh running as default. First time I found out about it was when reading the unit file... So I guess you weren't building those images? If you're building headless RPi images that's something you learn immediately.

I have a tendency to learn stuff in reverse. I used to make an SD Card ready, connected monitor and keyboard and enabled everything as needed. Then I got the task to deploy n-RPi's and looked at the image first to customize it for the requirements we had. That's when I looked around and saw the unusual unit file and tried to understand why the service would look at the boot partition to start a service. In the end I think I added the symlink to start the service thorugh systemd.

Re: 64 bit OS Raspberry Pi4 Benchmarks

#30
post #28

Earlier quoted context omitted.

So that's how they came up with that. As someone who normally installs "normal" Linux systems I find it quite irritating that you have to put a file somewhere, especially the boot record, to "enable" ssh of all things. Up until now I considered it a weird decision. (and I still think it is not optimal) I deploy my RPi's in the field and don't put a monitor on them so I would expect ssh running as default. First time…

Raspbian did originally come with SSH enabled by default but the default credentials pi/raspberry made it trivial for misuse: https://www.zdnet.com/article/linux-malware-enslaves-raspber...

Probably the right decision then. As I don't put them on public networks and delete the pi user this is of little concern to me, but given the target group, it is a simple safety measure.
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