Maybe sending it SIGINFO (^T in terminal) could help? Dunno if it's supported as far back as Tiger's.
(BSD thing, it's SIGUSR1 on GNU dd / Linux, the usability difference is that on darwin the terminal can conveniently send SIGINFO via ^T)
Here's what the output at the end or from SIGINFO looks like (this is running on my Mac mini and copying from /dev/zero to /dev/null):
``` 148908277760 bytes transferred in 6.917856 secs (21525206330 bytes/sec) ```
If I add `status=progress`, then it _also_ prints this every second:
``` 150617456640 bytes (151 GB, 140 GiB) transferred 7.001s, 22 GB/s ```
Oh yeah, my point is that if there's no `status=progress` support or if someone forgot to add it then in-flight progress and speed can be displayed in a pinch, and that feature is not well known.
"Every second" is a `while sleep 1` + `kill -INFO` loop away.
A typical full output of it is:
load: 2.91 cmd: dd 82396 running 0.02u 2.03s
87770+0 records in
87770+0 records out
92033515520 bytes transferred in 2.149378 secs (42818673830 bytes/sec)