Different IDE Adapter For Same Drive Shows 2x More and recovers more files

[eniwetok]

I have been trying to recover old email files from a 2002 IDE drive and finally got it all to work on a 2009 Win7 PC.

I originally used  bi-directional IDE to SATA adapter and it showed over 200k files on this old 60gig drive. I didn't have time to do the complete deep scan (10 hours), only 2%, but it brought up about 1500 emails 150 were completely recoverable.

I then went to a new Win10 PC and used an external case that had an adapter for IDE and it showed 98k files... and no email files showed up after complete 40 min deep scan. On both PCs I was using the newest version of Recuva and all the settings were the same.

So I went back to the 2009 computer using the same external case... and again only 98k files, no emails showed up.

So how is it that the bi-directional adapter allowed Recuva to access more files than the IDE adapter on the external drive case?  

FYI the adapter was by Best Connectivity and features some Sunplus SPIF233 Chipset... whatever that is.

[eniwetok]

UPDATE: I'm gasslighting myself. I got the 60gig drive to work on my Win10 PC using the adapter I used that found so many files. I had to dig out an ancient power supply to find the right plugs to power it. And it's not finding those 200k files I found last night. It's finding the same 98k files and no email even shows up. 

So at this point I have no idea why Recuva found so many files yesterday and not today.