Just a little test.
Copy your files from the 5400rpm drive to your 7500rpm drive.
Then disconnect the 5400 drive. You may find the whole thing loads faster.
The problem with IDE drives on the same channel is that they will transfer data the the speed of the slowest drive.
Also try reorganizing you photos into different folders so you're not displaying so many thumbnails at once (free performance improvment).
Also are your drives formated FAT or ntfs, ntfs is much faster for large number of files in any one directory
Ok, tried the HD thing, unplugged the 5400 with no change in performance. The folders with fewer photos do load faster (about 15 seconds for a folder of 8 photos to show the thumbnails vs 60-90 seconds for 60 thumbnails) BUT, this isn't practical for me to do with the number of photos I'll take per subject.
The drives are NTFS.
Is that P4 support HT?
Well, PCMark05 says that it has HT but is disabled. I've read around and if I have version C (or something like that) this chip does have HT and can be enabled... any ideas how to go about checking which version I have and if HT can be turned on?