Spotlight is CPU hog in Leopard

There was a time on Tiger when the Spotlight indexer processes (mdimport) would run nicely in the background and relinquish CPU cycles to anything else; you would hardly know they were there.

On Leopard now,  Spotlight appears to have been completely re-written and certainly does produce search results a lot faster than Tiger, but it does so at the expense of hogging your CPU(s) in an effort to get the indexing done (which are mdworker processes now). mds is a bit of hog too.

It took about 20 minutes to install the Office update, and it started a couple of minutes just before the Time Machine backup kicked off.  Coupled with the Spotlight indexing going on in the background as well (which didn't totally calm down until about half an hour after the install finished), made for a slightly unresponsive machine for a while!

So here's a tip - don't install the Office 2008 update (12.0.1) during a Time Machine backup!  Responsiveness is reduced a tad.

I filed a bug report with Apple.