Mac Pro Eight or Four Core?

[jlipkin]

I'm interested in how you found the info above. I have been searching the forums for a while and did not uncover anything about how thumbnails were rendered.

[Martin_Doudoroff]

Originally Posted by jlipkin

I'm interested in how you found the info above. I have been searching the forums for a while and did not uncover anything about how thumbnails were rendered.

I'm only speculating based on experience and clues, not because I've ever found an actual statement by Adobe on the subject. (God forbid!)

- first and foremost, the lack of any acknowledgement that Lightroom employs specific features of video display drivers
- the posted system requirements for Lightroom
- the comments on the Adobe forums (and the dearth of discussions on particular video display adapters)
- my background in applications that work with imagery and how they behave under different programming techniques
- the fact that my Lightroom performs poorly enough that I can actually watch it paint the screen

Notably, watching the processor utilization when working in the library is inconclusive. It may be more disk-limited than processor limited if previews are already cached.

I just spent a bunch of time searching the Adobe forums and came up with nothing but more vague clues. One thing I did learn is that Lightroom does use some OS-specific features for special effects, such as fading parts of the interface in and out (and the OS may employ display driver features to off-load that sort of operation). I still found no indication that Lightroom would directly use any special driver features for actual image processing.

The most curious thing I encountered were threads where clearly some individuals were seeing super-responsive performance out of the Lightroom interface whereas other were not. Alas, I didn't find one single applicable explanation for why this would be so. Display drivers certainly could be implicated, but nobody seems to be studying it.

[Jerry Skrocki]

I found an Adobe Tech Note for all of you Lightroom users experiencing performance problems:

View Document

[Martin_Doudoroff]

Originally Posted by Jerry Skrocki

I found an Adobe Tech Note for all of you Lightroom users experiencing performance problems:

View Document

The first two points in this tech note are crucial to all Lightroom users, and the third only applies to Windows users. (The third one has evidently been a huge revelation for a lot of Windows users.)

Alas, at this time, neither of the first two tech note points seem to have much bearing on the redraw performance questions I've been attempting to discuss. I've tried pretty much every variation of preview state I can come up with without any noticeable variation in performance.

Despite all the words I've invested in this thread, I feel I should make clear that Lightroom is completely usable on my system. I'm simply trying to determine whether I could be getting better redraw performance (particularly when scrolling through the Library) since Mr. Lipkin's testimony suggests he gets smoother performance on his Mac Book Pro.

I am beginning to have doubts about my display adapter—the ATI Radeon X1900 XT—or rather, about the quality of its drivers for OS X. Apple and NVidia are allegedly preparing an edition of the new 8800GT specifically for first-generation Mac Pro's like mine. I will certainly buy one when it becomes available (my ATI card has some bad vram on it that I didn't catch until after the warrantee expired). I'm looking forward to seeing what the consequences will be.