
Ask HN: RPi Cluster or a Dual Xeon? (How to compare Arm to Intel?) - jason_slack
I have a text processing project (and I asked a few questions about this here already). It&#x27;s currently Bash, GNU Parallel and other command-line tools. It&#x27;s getting moved to a C++ queue type design.<p>I&#x27;m trying to decide on an 8 node Raspberry Pi 3B+ cluster (about $500) or buying a used Dual Xeon (12 core) desktop (about $800, HP Z820).<p>The RPi cluster will help ensure my code scales well. However, I don&#x27;t quite know how speeds compare.<p>8 RPi&#x27;s x 4 cores each = 32 cores
2 x Xeon (12 cores) = 24 cores.<p>The RPI&#x27;s are 1.4GHz 64-bit quad-core ARMv8 CPU, 1 GB RAM.<p>The dual Xeon is 2.5ghz each, 64gb RAM.<p>How can I accurately think about the cores and speeds of each to decide what to do? This project will get larger within the next year and there will be more files to parse, manipulate, etc.<p>Edit: typos<p>Edit 2: typos<p>Edit 3: clarify RAM Z820 comes with<p>Edit 4: formatting
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snazz
I say the HP workstation. Not only will the work required to set up a bunch of
individual RPis to talk to each other effectively eclipse the work required to
configure a single machine, but the overhead from truly parallel, separate
computers is huge compared to a single machine where the individual cores
share CPU cache and memory. Disk performance, which I imagine to be a possible
issue with your project, is going to be orders of magnitude better on a real
SSD than slow, unreliable microSD cards. And 64GB RAM is 8 times as much as
the RAM on all the RPis combined. Considering that there’s more duplication of
code in memory required on each Raspberry Pi, you’re going to have much less
than 8GB total to work with.

Per watt, the ARM cores will beat the Intel ones, but per dollar you’re
getting a _much_ better deal on the desktop. The Raspberry Pi setup will cost
quite a bit more than $500 once you include fast microSD cards, power
supplies, cooling, an Ethernet switch, and cabling to hook everything
together.

Get the serious workstation-class machine, or consider buying a couple of used
rackmount servers on eBay for cheaper than $800 (minus the astronomical power
costs; you can heat your house with server hardware).

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jason_slack
Thank you for the thought our reply. I was actually thinking how to take the
heat from machines and moving it through my house. At least maybe heating my
laundry room so the water pipes stop freezing up :-)

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detaro
The workstation wins that easily. Faster, more RAM, not as IO-limited, ...

