512M
KVM testing on Ubuntu 20.04 via the Phoronix Test Suite.
HTML result view exported from: https://openbenchmarking.org/result/2005077-NI-512M1904688.
IOzone
Record Size: 4Kb - File Size: 512MB - Disk Test: Read Performance
IOzone
Record Size: 4Kb - File Size: 512MB - Disk Test: Write Performance
Phoronix Test Suite v10.8.4