I have a pretty decent setup, details here, and with the disk I/O rate I get with RAID5 it seems to me that compressing while ripping is a waste of system resources; IMHO I should be able to speed the ripping process if I could turn off compression. Is there a way to do so with this software?

Use a D/L disc if the disc is more than 4.38gbs. if its not you have to compress it to put it on a DVD5 disc. You can turn off the compression in the dropdown box. Just select whole disc without compression.

That's not the issue. I have been told that during the ripping process, the data that is stored to the HDD is compressed. I feel this is unnecessary, and would like to disable it. I am not talking about compressing to fit DVD5 -- I avoid that by using a DL disk as you suggest. With my setup(1080p) the loss of quality from compressing to DVD5 is obvious and annoying.

It's not killing me... ripping is pretty fast as it is. If there is a registry key or other tweak that can disable the compression I'd like to give it a whirl, that's all. If not, no biggie.

"Yes" files are compressed when ripped to your hard drive when putting them on a 4.78gb disc as I'm sure you are fully aware of, I would though be interested to hear where you heard that all files are compressed to your H/D when doing what I assume you say when in the process of doing a one to one copy using D/L material.
I'm not sure you can turn off the compression settings in pro, and I wonder why you would need to when using the one to one settings option, surely if the files are being compressed it would be pointless using 1Click and you just a easy obtain a perfect copy using Nero for instance....

I'm sure someone can enlighten us on this one... (perhaps from LGSoftware for instance)...

As already suggested by alan1467 if you select the exact copy - everything no compression - double layer if > 4.3gb option from the preset box then this will rip the movie to hdd without any compression.

See Post #5 in the thread that I linked to in my first post on this topic. After re-reading that more carefully, I may have misread it.

I had the idea that the files were compressed to the HDD using a form of lossless compression, something akin to WinZip, perhaps to save HDD space. This is a separate and distinct concept from the idea of compressing the content to fit smaller media, which is lossy and undesirable. I understand how to disable the latter. If the former is not happening in the first place, that answers my question.

We seem to be in agreement on this -- there would be no point in compressing the files to HDD unless one intended to go from DL to SL. My own mistake here - due to the way I misread the info.

That's the setting that I've been using. See post #6 above... I believe I just misread some info.

Thanks all for helping me pull my head out...

Anytime you need help just give us a post, we can usually sort things pretty fast here, especially when bubbles19 is on the job.