I'm working with a machine with a twe in it, running 2.0.  It's got 12
drives, all identical as far as I can tell:

twe0 at pci3 dev 1 function 0: 3ware Escalade
twe0: interrupting at irq 10
twe0: 12 ports, Firmware FE7S 1.05.00.065, BIOS BE7X 1.08.00.048
twe0: Monitor ME7X 1.01.00.038, PCB Rev5    , Achip 3.20    , Pchip 1.30-66 
twe0: port 0: ST3300831AS                              286168 MB
twe0: port 1: ST3300831AS                              286168 MB
twe0: port 2: ST3300831AS                              286168 MB
twe0: port 3: ST3300831AS                              286168 MB
twe0: port 4: ST3300831AS                              286168 MB
twe0: port 5: ST3300831AS                              286168 MB
twe0: port 6: ST3300831AS                              286168 MB
twe0: port 7: ST3300831AS                              286168 MB
twe0: port 8: ST3300831AS                              286168 MB
twe0: port 9: ST3300831AS                              286168 MB
twe0: port 10: ST3300831AS                              286168 MB
twe0: port 11: ST3300831AS                              286168 MB

Because the twe doesn't support more than 2T in a single RAID, I've got
the drives split up into two RAID5s, each formed from six of the
drives, one drives 0-5 and one 6-11:

ld0 at twe0 unit 0: 64K stripe RAID5, status: Normal
ld0: 1397 GB, 182405 cyl, 255 head, 63 sec, 512 bytes/sect x 2930351360 sectors
ld1 at twe0 unit 6: 64K stripe RAID5, status: Normal
ld1: 1397 GB, 182405 cyl, 255 head, 63 sec, 512 bytes/sect x 2930351360 sectors

(the above quote is from the most recent reboot).

However, I'm seeing a tremendous performance difference between ld0 and
ld1.  I have a disk exerciser program; when I run it on ld0, it runs at
a particular speed; on ld1 - in the same way - it runs at about 15% of
that speed.  Yes, that's 3/20 the speed - almost an order of magnitude.
At first I thought it might be that ld0 had priority over ld1, because
they were running simultaneously, but when the ld0 run finished, the
ld1 run didn't speed up any.

The only thing I can think of which would justify this would be if one
of the drives in ld1 has failed.  But the front panel lights give no
indication, and dmesg contains nothing at all from either twe or ld
since boot.  Is there any way to check the status of the arrays without
bringing the machine down to the BIOS?  If not, any idea how hard it
would be to hack such a thing into the driver?  Doing RAID seems
semi-useless if you don't hear about drive failures in time to replace
them before a second drive fails and you lose data.

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