[root@server23 ~]# time w
 12:28:04 up 8 days, 23:22,  1 user,  load average: 0.00, 0.02, 0.00
USER     TTY      FROM              LOGIN@   IDLE   JCPU   PCPU WHAT
root     pts/0    rrcs-24-97-153-8 12:09    0.00s  0.08s  0.00s w

real    0m0.003s
user    0m0.001s
sys     0m0.001s

Rather simple, so I want some more output. So I use the -v switch.

[root@server23 ~]# /usr/bin/time -v w
 12:28:32 up 8 days, 23:22,  1 user,  load average: 0.00, 0.02, 0.00
USER     TTY      FROM              LOGIN@   IDLE   JCPU   PCPU WHAT
root     pts/0    rrcs-24-97-153-8 12:09    0.00s  0.08s  0.00s /usr/bin/time -v w
        Command being timed: "w"
        User time (seconds): 0.00
        System time (seconds): 0.00
        Percent of CPU this job got: 100%
        Elapsed (wall clock) time (h:mm:ss or m:ss): 0:00.00
        Average shared text size (kbytes): 0
        Average unshared data size (kbytes): 0
        Average stack size (kbytes): 0
        Average total size (kbytes): 0
        Maximum resident set size (kbytes): 0
        Average resident set size (kbytes): 0
        Major (requiring I/O) page faults: 0
        Minor (reclaiming a frame) page faults: 269
        Voluntary context switches: 1
        Involuntary context switches: 0
        Swaps: 0
        File system inputs: 0
        File system outputs: 0
        Socket messages sent: 0
        Socket messages received: 0
        Signals delivered: 0
        Page size (bytes): 4096
        Exit status: 0

Now I'm confused. Every time I use -v, the user/system time shows up as 0.00 no matter what.

Any ideas why?

Looks like they're rounding down but not sure.

I guess. I don't understand why -v would be less precise than without -v

I would try running it on a program that takes longer. The time manpage says:

Also, setting -v changes the format string, so maybe it uses a different precision or something, dunno.