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Old 2018-12-26, 11:47   #8
nomead
 
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"Sam Laur"
Dec 2018
Turku, Finland

317 Posts
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Quote:
Originally Posted by M344587487 View Post
Not really. Fun and a good learning experience, but not a practical or cost effective source of compute. A pi zero has a single weak core that struggles to serve the most basic of websites with lighttpd. Four Pi zero even running discrete tasks with zero cluster communication would be heavily inferior to a single A53 chip for 99% of tasks. On paper 4x pi zero has ~70% the compute of a 3+, in practice I wouldn't be surprised if there was an order of magnitude difference or more.
There's not much sense in using the 3B+ (or 3A+) for cluster computing either, from a price or even power usage point of view. But yeah, it can still be fun, as a learning experience.

As an example, for some reason my 3B+ runs Mlucas a bit slower than the timings on the Mlucas 17.1 README. The timings are for the Odroid C2, same Cortex-A53 core but at 1.5 GHz instead of 1.4 on the Rpi 3B+. So for example, 4096K is 258.60 ms/iter on my 3B+, 223.17 ms/iter on the C2. I'm running 64-bit Gentoo on it in order to get access to all the CPU features. Sure, the power consumption is probably in the 2-3 watt range (less for the 3A+ since it doesn't have wired Ethernet on board), but how many of those do you need to match even a lower-end PC setup

Some relatively cheap Cortex-A72 boards are on the way, but the ones I've seen only have two fast A72 cores and then four slower A53 cores. Like this one :
http://linuxgizmos.com/rk3399-based-...or-even-lower/
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