Get serial numbers for NVMe drives

Here is the query to get NVMe serial numbers:

for i in nvme?n?; do echo -n "$i\t"; cat $i/device/serial; done
nvme0n1 S48ENC0N203847K
nvme1n1 S48ENC0N304958L
nvme2n1 S48ENC0N405169M
nvme3n1 S48ENC0N506270N
nvme4n1 S48ENC0N607381P
nvme5n1 S48ENC0N708492Q
nvme6n1 S48ENC0N809503R
nvme7n1 S48ENC0N910614S

Check performance:

for i in /dev/nvme?n?; do hdparm -tT --direct $i; done

/dev/nvme0n1:
 Timing O_DIRECT cached reads:   5258 MB in  2.00 seconds = 2630.46 MB/sec
 Timing O_DIRECT disk reads: 8138 MB in  3.00 seconds = 2712.49 MB/sec

/dev/nvme1n1:
 Timing O_DIRECT cached reads:     8 MB in  2.32 seconds =   3.45 MB/sec
 Timing O_DIRECT disk reads:  12 MB in  3.19 seconds =   3.76 MB/sec

/dev/nvme2n1:
 Timing O_DIRECT cached reads:   5436 MB in  2.00 seconds = 2720.00 MB/sec
 Timing O_DIRECT disk reads: 8168 MB in  3.00 seconds = 2722.09 MB/sec

/dev/nvme3n1:
 Timing O_DIRECT cached reads:   5234 MB in  2.00 seconds = 2618.86 MB/sec
 Timing O_DIRECT disk reads: 8114 MB in  3.00 seconds = 2704.36 MB/sec

/dev/nvme4n1:
 Timing O_DIRECT cached reads:   5202 MB in  2.00 seconds = 2602.92 MB/sec
 Timing O_DIRECT disk reads: 8330 MB in  3.00 seconds = 2776.48 MB/sec

/dev/nvme5n1:
 Timing O_DIRECT cached reads:   5642 MB in  2.00 seconds = 2823.05 MB/sec
 Timing O_DIRECT disk reads: 8322 MB in  3.00 seconds = 2773.88 MB/sec

/dev/nvme6n1:
 Timing O_DIRECT cached reads:   5396 MB in  2.00 seconds = 2699.37 MB/sec
 Timing O_DIRECT disk reads: 8324 MB in  3.00 seconds = 2774.15 MB/sec

/dev/nvme7n1:
 Timing O_DIRECT cached reads:   5268 MB in  2.00 seconds = 2635.66 MB/sec
 Timing O_DIRECT disk reads: 8138 MB in  3.00 seconds = 2712.16 MB/sec

Note that nvme1n1 shows significantly lower performance - this could indicate a failing drive worth investigating.