[Discuss] Raspberry PI[4,5] as infrastructure?

[markw at mohawksoft.com]

> markw at mohawksoft.com wrote:
>> I have a RPI5 running ZFS, PostgreSQL, a DLNA server, and a full
>> development stack that compiles just about any code I have laying
>> around.
>>
>> These things chave 8 gigs of RAM, 4 CPUs, use 15 watts of power, and
>> cost
>> less than a video card. My desktop is considerably bigger, but the core
>> speed is only 2 or 3 times as fast as the ARM.
>
> My rule of thumb: humans doing normal desktop tasks (whatever is
> not pushing the envelope of that computing generation) cannot
> distinguish less than a 100% performance improvement.

No argument there depending on what the human is doing. I'f I'm compiling
a large program or doing a large query on a database, CPU performance and
I/O make a difference.

>
> (AKA most of the time, everything is instantaneous. You only
> notice when it isn't.)

Hence finding the XZ exploit :-)

>
> ...
>
>> Would a stack of RPI5s, controlled by some sort of docker look-alike,
>> perform better than a huge VMware server? Would it perform better than a
>> large kubernetes cluster? Would they be more secure because they are
>> physically separated.
>>
>> Thoughts?
>
> RPI - all of them to date - are limited by I/O. Let's suppose
> the unit of computing is an 8GB RPI5, and the cost per unit to
> interconnect and power and cool them is $20, so for each $100
> increment we get 4 2.4GHz cores and 8GB RAM, a GPU and two lanes
> of PCIe 2.0, and another 15W.
>
> For some workloads this is great. If you were building a
> security camera hub, for example, being able to add two cameras
> worth of realtime processing for that price is very nice.
> Anything where the individual tasks are reasonable but there are
> a lot of them coming in seems like a good bet.
>
> But somewhere around the 4-8 Pi mark, it will become obvious
> that you need all three of better storage, networking, and
> interconnections -- and you can only solve one of those at a
> time with the RPI5. The coordination overhead starts taking a
> larger chunk of each unit. Pretty soon you run into Amdahl's
> law: eventually, the non-parallelizable part of any process will
> be the bottleneck.

This is something I have encountered for so long. Everyone rejects out of
hand things that do not scale infinitely. Is this why pick-up trucks are
more like military troupe carriers than utility vehicles?

I still assert, 99% of the computing that people actually need is easily
handled with no specialize scaling architecture. Everyone is so hell bent
on building the latest and greatest technologies that they over build
their data infrastructure. Its wasteful.

Yes, sure, if you are building room-size compute facilities that do an LLM
or a social media platform, then yea, go for it, but most of the people
who build in the cloud don't do anything like this.

I won't call it a niche because it is a VERY big segment of the compute
market, but my assertion is that a Raspberry PI5 would more than suffice
for a company file server, database, internal infrastructure, etc. Think
about your local supermarket. All the POS terminals could easily be
handled by a raspberry PI and a USB-3 disk bay.