Maximum Transfer Size, ATA, and UFS2, was lowered? How?

[David Kelly]

I have been watching the maximum "KB/t" for devices using "systat -v". 
A week or two ago prompted by other messages here experimented with 
"tunefs -m 5 ad0s1f" and very shortly thereafter restored it to the 
original value of 8. Previously 127 KB/t was often seen for large file 
actions. Currently seems that the limit has been dropped from 128k to 
64k. All I can think that I did was flip the minfree percentage using 
tunefs from 8 to 5 and back to 8. How can I restore the fs 
characteristics back to normal?

System is 5.2.1-p9. More possibly useful information:

# bsdlabel /dev/ad0s1
# /dev/ad0s1:
8 partitions:
#        size   offset    fstype   [fsize bsize bps/cpg]
   a:   524288        0    4.2BSD     2048 16384 32776
   b:  4140688   524288      swap
   c: 241248042        0    unused        0     0         # "raw" part, 
don't edit
   d:   524288  4664976    4.2BSD     2048 16384 32776
   e:   524288  5189264    4.2BSD     2048 16384 32776
   f: 235534490  5713552    4.2BSD     2048 16384 28552
# dumpfs -m /dev/ad0s1f
# newfs command for /dev/ad0s1f (/dev/ad0s1f)
newfs -O 2 -U -a 8 -b 16384 -d 16384 -e 2048 -f 2048 -g 16384 -h 64 -m 
8 -o time -s 58883622 /dev/ad0s1f

--
David Kelly N4HHE, dkelly at HiWAAY.net
========================================================================
Whom computers would destroy, they must first drive mad.