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by ody4242 97 days ago
I would have benchmarked with an instance that has local nvme, like c8gd.4xlarge.
2 comments
namibj 97 days ago
Do they make any promises about persistence of local NVMe after something like a full-region power outage yet? Because if you can't do durable commit on a single-region cluster that will be just temporarily unavailable without loosing committed data if something like that happened, it's not quite there unless you still stream a WAL to storage that they do promise you will survive a full blackout of all zones that store (part of) the data.
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amluto 96 days ago
Yes. They promise to wipe your data. That SLA has all the nines you can ask for as long as you measure it in the right direction :)
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LunaSea 97 days ago
You already lose your data after instance restart so I think that full region outage is already out of question.
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ody4242 96 days ago
Idk how an AWS region would respond to a power outage, but i have tested this in AWS Outpost, and there, if you power down a rack, then power it back again, the baremetal instances will not be recreated. (I was surprised as I was expecting the EC2 health check to terminate them, but it does not work like that.) My understanding is that if you stop/start an instance, your local storage is gone (as the instance might even end up in a different host), but if you just reboot the instance, it should keep the local storage.
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szarnyasg 96 days ago
That's a good point. I re-ran the benchmark on two instances:

- c8gd.4xlarge - this has a single 950 GB NVMe SSD.

- c5ad.4xlarge - this has 2 x 300 GB disks, which I put in a RAID 0 array. There are no c6ad.4xlarge instances, so this is the closes NVMe-enabled approximate to ClickBench's most popular choice, c6a.4xlarge.

I also added results from my local dev machine, a MacBook M1 Max with 64 GB RAM and 10 cores.

Here are the results:

  | machine        | cold_run_avg | cold_run_sum | hot_run_avg | hot_run_sum |
  | -------------- | -----------: | -----------: | ----------: | ----------: |
  | macbook m1 max |         0.48 |        20.68 |        0.43 |       18.60 |
  | macbook neo    |         1.39 |        59.73 |        1.26 |       54.27 |
  | c8gd.4xlarge   |         0.51 |        22.04 |        0.24 |       10.36 |
  | c5ad.4xlarge   |         1.29 |        54.14 |        0.55 |       22.91 |
  | c6a.4xlarge    |         3.37 |       145.08 |        1.11 |       47.86 |
  | c8g.metal-48xl |         3.95 |       169.67 |        0.10 |        4.35 |
On the cold run, the MacBook is on par with the c5ad.4xlarge. The c8gd.4xlarge is about ~2.5x faster on the cold run.

I know this is moving the goalpost, however, it's quite interesting that both of these cloud instances with instance-attached storage are still outperformed by the M1 Max (which is 4+ years old) on the cold run. And they would quite likely lose against the latest MacBook Pro with the M5 Pro/Max on both the cold and the hot runs. But that's an experiment for another day.

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