NetBSD disk performance on VirtualBox

[Sad Clouds <cryintothebluesky%gmail.com@localhost>]

Hello, are there known I/O performance issues with NetBSD on VirtualBox?
I've setup two similar VMs, one Linux, another one NetBSD, both use
SATA virtual controller with one disk.

Writing 1GB file sequentially:
- Linux gives 425MB/sec,
- NetBSD gives 27MB/sec.

Repeated this several times, and got the same result.

Is this expected with NetBSD?