Are there any I/O limits on VDS?

We apply the following threshold limits:

Hyper-V block size - 8 KB

SSD-2, SSD-3 — 8000 IOPS (512 Mbps)
SSD-4 — 16000 IOPS (1024 Mbps)
SSD-5, SSD-6, SSD-7, SSD-8 — 24000 IOPS (1536 Mbps)

KVM block size - 4 KB

SSD-1 — 4000 IOPS (128 Mbps)
SSD-2, SSD-3 — 8000 IOPS (256 Mbps)
SSD-4 — 16000 IOPS (384 Mbps)
SSD-5, SSD-6, SSD-7, SSD-8 — 24000 IOPS (576 Mbps)