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Great news. I'd like to see how a vCPU compares between arm64 and amd64 but not sure how to best go about it. I've created VMs for both with 4 vCPU and will run the phoronix benchmark suite. After that I'll probably try 16 arm vs 8 amd vCPU because that's a closer match in terms of price. Any suggestions welcome but I also don't want to spend too many hours on it. Will post results.

Ran the kernel build benchmark (result is seconds, lower is better):

   AMD64:
        272.916
        273.128
        270.477
   ARM64:
        1011.799
        1004.713
        1015.261
So the ARM CAX21 instance for 6.49 EUR/month took roughly 3.7x as long as the AMD CPX31 instance which costs 13.60 EUR/month. A roughly 2.1x price difference. Here the ARM instance did not shine in a kernel-compile-per-eur metric.

Also ran sysbench cpu --time=60 --threads=4 run

   AMD64: events per second: 14681.70
   ARM64: events per second: 13455.11
In this test the both are very close.


Additional benchmarks:

sysbench memory --time=60 --threads=4 run

   AMD64: 5859951.00 per second
   ARM64: 6052749.14 per second
Here ARM had a lead.

Next up I timed compiling nodejs. time make -j4. I ran the test two times and took the faster result for each.

   AMD64: 
      real    28m46.385s
      user    107m48.971s
      sys     5m12.994s
   ARM64:
      real    39m18.443s
      user    146m25.801s
      sys     7m53.271s
Here ARM seems to be roughly 36% slower. This is actually pretty good considering the price difference.

Rescaled the ARM VM to 8 vCPUs:

      real    22m20.624s
      user    162m30.176s
      sys     8m50.104s
So now the ARM offering is noticably faster than the AMD instance but still cheaper. 12.49 Eur vs 13.60 Eur.

What I learn from these benchmarks is that you might get some really good value out of these ARM instances if your usecase is not impacted all too much in terms of performance.


The main problem I'd think is that by being "virtual" you never really quite know if you're seeing how it would run in "real life".

Personally, if I were to do it, and I had some sort of load-balanced application that uses multiple backends/frontends/whatever, is balance across the two and compare over time.

And to be 'fair' you'd want to compare similar pricing.

Or if you had a consistent group maybe try a Minecraft server and move it between the two every week and see what people "feel"?


>I'd like to see how a vCPU compares between arm64 and amd64

That depends on how many vCPUs are they running on each physical core for both x86 and ARM.


Yes and we might never know or maybe it's not even static.

This will never be 100% scientific or correct since there are many factors that come into play, stuff like noisy neighbour for example.

What I'm trying to get is a ballpark idea of how their arm vCPU compares to the amd equivalent.




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