low performance on /dev/drbd1

[serlis87]

Hi. I am testing DRBD (kmod version 9.2.2). When I testing a disk without drbd (fio -ioengine=libaio -direct=1 -name=test -bs=4k -iodepth=32 -rw=randwrite -runtime=60 -filename=/dev/sdc) I get 230k iops. However, a similar test, but on /dev/drbd1 shows no more than 50k-60k iops. I tried disabling the resource (drbdadm disconnect r0) to exclude the replication network and test again, but got the same result. Tell me, please, what could be the reason for the degradation of local performance /dev/drbd1?

My *.res file in attach
r0.txt