Kirk, not sure how much it matters, but
Søren and I both have the original Extreme IV cards, NOT the 45 MB/s edition. (That said the older original cards should still achieve speeds of about 39 MB/s.) However I just wanted to point it out as something to keep in the back of your mind in case it starts to become a common denominator.
The only machine I have running 10.6 is a MacBook Pro and combined with the other issues (like spell check) I'm in no hurry to upgrade the desktop. As I mentioned before, PM 4.6.2.1 running on OS 10.5.8 has the fastest Ingest speeds I've ever seen and I'm loving it.
The only thing that was different about when I got the super slow speeds was when I was working out of my truck as opposed to having the laptop setup on a desk.
Not sure if this helps but I just did a very unscientific test between the two machines. I quit and reopened Photo Mechanic before each Ingest.
Sandisk Extreme IV (original) 4 GB CF card
180 JPEGs plus 30 WAVs from a Canon EOS 1D Mark II N
Finder reports: 1.04 GB on disk (1,112,789,705 bytes) for 210 items
Ingest to single location (different folder each time), applying a single field in IPTC Stationary
Mac Pro, OS 10.5.8 running PM 4.6.2.1Sandisk FW800 Reader: 37.5 secondsLexar FW 800 Reader: 33.0 secondsMacBook Pro, OS 10.6.2 running PM 4.6.2.2 beta 2Sandisk FW800 Reader: 1 minuteLexar FW 800 Reader: 58.9 secondsFor reference, assuming my math is correct, all of these speeds are under the 39.7 MB/s rate Rob Galbraith reports in his speed tests for the combo of my specific CF card and Sandisk reader, but they are still plenty fast.
According to Galbraith the Sandisk and Lexar readers use the same chipset which makes me think it wouldn't be a situation where one suffered from the problem but the other didn't, but I'm no expert.
SanDisk's flagship CompactFlash-only reader utilizes a speedy OXFW912 FireWire 800/400 controller from Oxford Semiconductor...
The read speeds for the Delkin Reader-39, Hoodman RAW UDMA FireWire 800, Lexar Professional UDMA FireWire 800 and Synchrotech CFFire800 Pro are effectively identical to this SanDisk reader, because all four utilize the same controller from Oxford.