Performance counter : PhysicalDisk: % Disk Time

We have a DataWarehouse process that, at times, causes this Perfmon counter to exceed > 1800 (for several minutes at a time. Not good).

Question: How can that counter exceed 100 * (number of spindles in array)? (I suspect that numbers in that range are meaningless except to point out a disk bottleneck.)

TIA,

barkingdog

P.S. We use sql 2005, x64 edition, with SP1.

http://www.demandtech.com/FAQsdisk.htm#DiskFAQ1

Frequently Asked Questions about Disk
1. The Logical/Physical Disk % Disk Time counters look wrong. What gives?

http://support.microsoft.com/kb/269481

not about:: We use sql 2005, x64 edition, with SP1.