Weird performance differences between cloud vendors

Hi,

I have run a test with pgbench against two cloud vendors (settings,
parameters almost the same).

Both Postgres (or whatever they do internally when they call it as
Postgres offering, NOT Aurora or so :-) )

I have got a strange result that cloud vendor 1 is performing almost
everywhere better in matter of

read and write but except in the init phase of pgbench it took almost
double the time.

> /pgbench -i -IdtGvp -s 3000 "${PG_DATABASE}"/
> /pgbench -c 50 -j 10 -P 60 -r -T 3600 "${PG_DATABASE}"/

| Metric | cloud vendor 1 (small) | cloud vendor 1 (large) | cloud
vendor 2 (small) | cloud vendor 2 (large) |
|----------------------------------|------------------------|------------------------|-------------------|-------------------|
| **Initialization Time** | 60m52.932s | 3h0m8.97s | 32m7.154s |
5h14m16s | | **Benchmark Duration** | 3600s (1 hour) | 3600s (1 hour) |
3600s (1 hour) | 3600s (1 hour) | | **Transactions per Second** |
399.460720 | 9833.737455 | 326.551036 | 3314.363264 | | **Latency
Average (ms)** | 125.124 | 6.507 | 153.106 | 19.309 | | **Latency StdDev
(ms)** | 154.483 | 44.403 | 59.522 | 4.015 | | **Initial Connection Time
(ms)** | 557.696 | 174.318 | 1688.474 | 651.087 | | **Transactions
Processed** | 1,438,437 | 35,400,215 | 1,175,081 | 11,929,631 | |
Statement (ms) | cloud vendor 1 (small) | cloud vendor 1 (large) | cloud
vendor 2 (small) | cloud vendor 2 (large) |
|-----------------------------|------------------------|------------------------|-------------------|-------------------|
| BEGIN | 8.599 | 0.545 | 9.008 | 1.398 | | UPDATE pgbench_accounts |
38.648 | 2.031 | 27.124 | 4.722 | | SELECT pgbench_accounts | 12.332 |
0.676 | 17.922 | 1.798 | | UPDATE pgbench_tellers | 17.275 | 0.853 |
20.843 | 1.831 | | UPDATE pgbench_branches | 18.478 | 0.862 | 21.941 |
1.743 | | INSERT INTO pgbench_history | 16.613 | 0.827 | 18.710 | 1.501
| | END | 13.177 | 0.708 | 37.553 | 6.317 |

Of course no one knows the magig underneath what some cloud vendors are
doing underneath but does anyone have some

ideas what the reason could be or how I could do better testing to find
this out?

Cheers

Dirk