ar performing abysmally

[Jim Bell]

Upgraded to FreeBSD-10/gcc48. One project puts a dozen object files in a 
static lib via ar, but now that takes a long time, and it's not CPU.

“time ar -v -c -u -q ...” : 362.62 real         0.11 user 0.82 sys.
“time ar -v -c -r -u -s ...”: 407.94 real         0.13 user 0.80 sys

iostat's numbers don't look to impressive to me, but my ISP says they're 
normal. 'dd' writes to the disk plenty fast. I moved off the RAID-1 but 
it made no difference. I have 64G swap and it doesn't get touched.

Truss shows it reading the input files and writing the output, but write 
times are all over the place. truss -D ...
0.000031869 write(3,...,10240) = 10240 (0x2800)
0.083054581 write(3,...,10240) = 10240 (0x2800)
0.000029723 write(3,...,10240) = 10240 (0x2800)
0.841429575 write(3,...,10240) = 10240 (0x2800) <-- seems pretty slow!
0.000015954 write(3,...,10240) = 10240 (0x2800)
0.000022723 write(3,...,10240) = 10240 (0x2800)

Truss shows 800 write's that take over 0.7 sec, similar to the above.

Where's my problem? What to try next? Is it even the disk?

Thanks in Advance,
-Jim