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How similar are vCPUs across cloud vendors? Are they approximately the same speed, or >1.5x different? Or...?

by gpm 6y ago

jeppesen-io 6y ago
1.5x would be quite a large difference, would not expect that cpus are complex, varrying instruction sets and such, you need to benchmark your particular workload to get a meaningful number Not to mention sight difference on the underlying hypervisor, that may or may not impact your workload
freediver 6y ago
Can be very different. I recently benchmarked it with a simple python based benchmark (as I use python most often) and in some cases the differences were even 2x. Some results and benchmark here: https://github.com/vprelovac/python-speed https://github.com/vprelovac/python-speed These were coming mostly from the fact that some providers updated to the latest gen AMD chips which was making big difference compared to 3-4 yr old Intel chips.
deathanatos 6y ago
They're not even necessarily comparable within a vendor. The underlying hardware changes, and newer generations will (hopefully) perform better than previous generations. E.g., Azure publishes CoreMark perf stats for some¹ of their VM types, and the score can vary by 60%. (Now, I don't know how CoreMark scores translate into raw CPU perf.) But hopefully it's trivial to show that 1 vCPU of yesteryear's model != 1 vCPU of this year's model. I think EC2 some sort of "ECU" to try to normalize them? I don't know of any other such attempts though. ¹regrettably, the older ones.
zylepe 6y ago
For digitalocean at least, there is quite a large difference between the “basic” droplets and ones with dedicated vcpus. In this table, they both look the same. I’ve seen 2-4x differences between the two: https://rob006.net/en/blog/how-more-efficient-is-cpu-optimized-droplet-than-standard-droplet-on-digitalocean/ https://rob006.net/en/blog/how-more-efficient-is-cpu-optimiz...
mmcconnell1618 6y ago
Azure used to sell physical cores but AWS was selling Hyper-threaded cores. This made a big difference on pricing and performance of certain workloads like Oracle. These days, everything seems to be sold under the term vCPU which is an abstraction to represent the performance you can expect and is roughly similar to a hyper-threaded core. https://azure.microsoft.com/en-us/blog/introducing-the-new-dv3-and-ev3-vm-sizes/ https://azure.microsoft.com/en-us/blog/introducing-the-new-d...
christophilus 6y ago
More than 1.5x variation in my tests. And dedicated Ryzen servers obliterate anything else in their price range.

How similar are vCPUs across cloud vendors? Are they approximately the same speed, or >1.5x different? Or...?

by gpm 6y ago

How similar are vCPUs across cloud vendors? Are they approximately the same speed, or >1.5x different? Or...?

1.5x would be quite a large difference, would not expect that cpus are complex, varrying instruction sets and such, you need to benchmark your particular workload to get a meaningful number Not to mention sight difference on the underlying hypervisor, that may or may not impact your workload

freediver 6y ago

Can be very different. I recently benchmarked it with a simple python based benchmark (as I use python most often) and in some cases the differences were even 2x. Some results and benchmark here: https://github.com/vprelovac/python-speed https://github.com/vprelovac/python-speed These were coming mostly from the fact that some providers updated to the latest gen AMD chips which was making big difference compared to 3-4 yr old Intel chips.

deathanatos 6y ago

They're not even necessarily comparable within a vendor. The underlying hardware changes, and newer generations will (hopefully) perform better than previous generations. E.g., Azure publishes CoreMark perf stats for some¹ of their VM types, and the score can vary by 60%. (Now, I don't know how CoreMark scores translate into raw CPU perf.) But hopefully it's trivial to show that 1 vCPU of yesteryear's model != 1 vCPU of this year's model. I think EC2 some sort of "ECU" to try to normalize them? I don't know of any other such attempts though. ¹regrettably, the older ones.

zylepe 6y ago

For digitalocean at least, there is quite a large difference between the “basic” droplets and ones with dedicated vcpus. In this table, they both look the same. I’ve seen 2-4x differences between the two: https://rob006.net/en/blog/how-more-efficient-is-cpu-optimized-droplet-than-standard-droplet-on-digitalocean/ https://rob006.net/en/blog/how-more-efficient-is-cpu-optimiz...

mmcconnell1618 6y ago

Azure used to sell physical cores but AWS was selling Hyper-threaded cores. This made a big difference on pricing and performance of certain workloads like Oracle. These days, everything seems to be sold under the term vCPU which is an abstraction to represent the performance you can expect and is roughly similar to a hyper-threaded core. https://azure.microsoft.com/en-us/blog/introducing-the-new-dv3-and-ev3-vm-sizes/ https://azure.microsoft.com/en-us/blog/introducing-the-new-d...

christophilus 6y ago

More than 1.5x variation in my tests. And dedicated Ryzen servers obliterate anything else in their price range.