$ sudo fio --bs=4k --ioengine=libaio --iodepth=32 --size=500m --direct=1 --runtime=60 --filename=/dev/rd0 --rw=randread --numjobs=1 --name=test
test: (g=0): rw=randread, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=libaio, iodepth=32
fio-3.16
Starting 1 process
test: (groupid=0, jobs=1): err= 0: pid=12967: Sat Jun 19 14:50:18 2021
  read: IOPS=307k, BW=1199MiB/s (1257MB/s)(500MiB/417msec)
    [ ... ]
Run status group 0 (all jobs):
   READ: bw=1199MiB/s (1257MB/s), 1199MiB/s-1199MiB/s (1257MB/s-1257MB/s), io=500MiB (524MB), run=417-417msec
Disk stats (read/write):
  rd0: ios=0/0, merge=0/0, ticks=0/0, in_queue=0, util=0.00%