[peferron]

> Also, for your local disk test, on GCP, disk size makes a difference to get the best performance. The larger the disk, the better the performance. Disk read/write performance also comes out of the available network bandwidth

Do you have a source for local SSD performance coming out of the available network bandwidth? According to GCP docs [1], this only applies to persistent disks. Local SSD perf depends only on disk size and choice of SCSI/NVMe interface.

According to another GCP doc [2], local SSDs are all 375 GB in size. For comparison, c5d.4xlarge has 400 GB, which is very close. So I don't see anything wrong in the benchmark unless they messed up and ran it against the persistent root disk instead of the local SSD.

[1] https://cloud.google.com/compute/docs/disks/performance#type...

[2] https://cloud.google.com/compute/docs/disks/#localssds

[WestCoastJustin]

You are right. Sorry for the confusion. It is only PD (Persistent Disk) that comes out of network bandwidth. Anything on the NVMe SSD would be totally local to the machine (no network caps, etc). The article doesn't really say if they are using SSD PD or SSD NVMe for GCP. Also, disk size does matter for the NVMe SSD and performance (as you can stripe them together by adding more; up to 4). You can see the #'s by using the console and playing around with adding more NVMe SSDs (via this doc [1]).

  Size      Random IOPS                Throughput limit (MB/s)
  375GB     169,987 (r)  90,000 (w)      663 (r)   352 (w)
  750GB     339,975 (r) 180,000 (w)    1,327 (r)   705 (w)
  1125GB    509,962 (r) 270,000 (w)    1,991 (r) 1,057 (w)
  1500GB    679,950 (r) 360,000 (w)    2,650 (r) 1,400 (w)

[1] https://cloud.google.com/compute/docs/disks/local-ssd