Raspberry Pi 3A+
 

[URL]https://www.raspberrypi.org/magpi/raspberry-pi-specs-benchmarks/[/URL]

[LIST][*]A cut down version of the the 3B+ with the same CPU[*]Half the RAM at 512MB[*]Less board components for better out of the box power efficiency[*]Smaller board footprint at 67×56 compared to 85x56 for 3B+[*]Costs £22.30 compared to £30.10 for 3B+[/LIST]Buying 10+ at a time the cost goes down to £20 per 3A+ board, so a compute cluster with 10 of them could be made for £250-£300 including networking, power delivery and storage. I don't know how that compares to x86 or other ARM solutions but it sounds like a fun project.

[QUOTE=M344587487;500394][URL]https://www.raspberrypi.org/magpi/raspberry-pi-specs-benchmarks/[/URL]

[LIST][*]A cut down version of the the 3B+ with the same CPU[*]Half the RAM at 512MB[*]Less board components for better out of the box power efficiency[*]Smaller board footprint at 67×56 compared to 85x56 for 3B+[*]Costs £22.30 compared to £30.10 for 3B+[/LIST]Buying 10+ at a time the cost goes down to £20 per 3A+ board, so a compute cluster with 10 of them could be made for £250-£300 including networking, power delivery and storage. I don't know how that compares to x86 or other ARM solutions but it sounds like a fun project.[/QUOTE]

I am very pleased with my 3B+, but I wonder if there is a 64-bit Gentoo image for the 3A+. I was able to compile straight 64 bit C, which had been running on X64, without any issues. It is now up for 128 days :smile:

[QUOTE=M344587487;500394][LIST][*]Costs £22.30 compared to £30.10 for 3B+[/LIST][/QUOTE]Does that include a power adapter, SD card and Ethernet cable?


This is what I paid for my total kit:

Raspberry Pi 3B+ €39.95
Heat sink kit €4.95
Micro-USB power adapter (5V 2.5A) €7.99
Official Raspberry Pi 3/3B+ case €8.95
Sandisk 32GB Ultra + adapter €16.99
----------------------------------------
€78.83 (includes 21% VAT)

Which works out to about ~$90 or ~£70

Ok, you could probably save some since you don't need a case and with smaller SDcard (without adapter).
But I would highly recommend the small heat sinks if you run it flat-out. And the 5V 2.5A micro-USB adapter is also nice, since it gives some headroom that most micro-USB power adapters don't have (most are 1A or 2A). If you've got some spare Ethernet cables than that could save you a few bucks also.

[QUOTE=VictordeHolland;500400]Does that include a power adapter, SD card and Ethernet cable?
...[/QUOTE]Just the board. I've priced up what it would cost all inclusive for a self-contained solution using the cheapest parts I can find from farnell, ebay and ebuyer, in bulk where it makes sense:

[B]16x wireless using SD cards[/B]
[LIST][*]16x (3A+, heatsink, micro USB cable, SD card): £373[*]Wireless router: £14.40[*]2x 12 port USB charger: £22[/LIST]
Total: ~£410
Cost per pi: ~£25.60

[B]16x wired using an external HDD and network booting[/B]
[LIST][*]16x (3A+, heatsink, micro USB cable, ethernet to USB adapter)[*]2x 12 port USB charger: £22[*]16 port switch: £29[*]500GB external HDD: £29[*]1 USB hub: £1[/LIST]
Total: ~£420
Cost per pi: ~£26.30

The wireless solution is a lot less messy hardware-wise but would likely be a nightmare to maintain. Relying on SD cards is not ideal but you cannot network boot over wifi. The wired solution has the benefit of using a HDD for storage but it's unfortunate that ethernet adapters need to be used. Network booting may not work over an adapter so that's a question mark. If it can work it'd be a neat solution, just a single HDD to worry about that can be easily backed up or even imaged to a new drive for a new cluster if desired. For a couple more quid you could use a 3B+ in the wired setup instead of one of the 3A+ to eliminate some potential headaches of using a USB hub. That pi could also be the only one that needs to communicate with the outside world for primenet, the rest can have wifi disabled to save some juice.