Memory Management - Photoshop CS5 and LR3 - Just wondering...

[solardarkroom.com]

I was waiting for an excuse to upgrade Photoshop CS4 to CS5 and got my chance recently. I was attempting a focus stack of 49 images from my 5DmkII when I ran into the RAM access limits of 32bit apps. I'm thrilled with CS5 (the final image was a great success) and most of all I was excited to see it happily grabbing over 9GB or RAM. Granted the task was large but it got me wondering. Why won't LR3 (64bit) just use whatever is available? Would it make things snappier? Would module switching be faster? Would brush and gradient type work be more responsive? Or is this more a matter of CPU horsepower? I've seen LR3 use up to 4GB when I'm busy but have wondered why it won't use more when it's available. Is this based on design concepts in software engineering? I'm not complaining: full stop. I'm still giddy with this combination of apps. The geek in me just can't resist wondering about this stuff and I know some of you folks are experts.
Cheers,
David
PS MacPro-2006 Quad 2.66 GHz, 13GB RAM, 10.6.always up to date

[Schewe]

Why won't LR3 (64bit) just use whatever is available?

Memory usage is different between Photoshop–which DOES try to load an entire image in ram and Lightroom–which does NOT normally try to load an entire image in ram. Lightroom's memory requirements are different. Most things in Lightroom are not ram limited (as long as LR has enough free ram). LR is more limited by CPU and disk I/O.

So, the fact that LR isn't accessing more ram means it simply doesn't need it. Grabbing MORE ram like Photoshop does, won't make Lightroom any faster. It's only when Lightroom is ram starved (at or near the minimum ram requirements) that adding more ram will help.

Bottom line, if you want Lightroom to be faster, get a faster CPU and/or faster hard drives.

[Mark D Segal]

Jeff, I suppose the point you're making here is that the two applications are different kinds of editors - right? LR isn't a pixel editor - it's writing metadata based on instructions the user provides from feedback of an image preview which is a much smaller file than a three-channel pixel-based image, whereas Photoshop is the latter and therefore much more memory intensive.

[Schewe]

Mark,

Correct...as long as Lightroom has "enough ram", adding more ram doesn't help. With Photoshop, depending on the image sizes, more ram is better when running in 64-bit.

[solardarkroom.com]

Thank you for the explanation. I'll file it away as ammo for buying that 12 core tower Then I'll need a justification for Canon's new long macro that's sure to come out, and a 135f2, that convertible I saw the other day...

[datro]

Bottom line, if you want Lightroom to be faster, get a faster CPU and/or faster hard drives.

Would it be fair to say that regarding faster disk drives, it's more important to have a fast disk for the catalog vs. the raw files?  I'm in the process of building a new machine and I'm planning to put the catalog on a SSD drive.  I'm hoping this will improve my overall responsiveness of LR.

Dave

[Steve Weldon]

Would it be fair to say that regarding faster disk drives, it's more important to have a fast disk for the catalog vs. the raw files?  I'm in the process of building a new machine and I'm planning to put the catalog on a SSD drive.  I'm hoping this will improve my overall responsiveness of LR.

Dave

Depends on your priorities in LR.  If you cruise a large catalog and want very fast viewing then yes.. SSD.  If you are talking about processing working files then the SSD is put to better use as a working drive.

Ultimately, the more CPU power and ram the better.  LR responds well to cubic inches/horsepower.  Secondary is the drives.

I find Seagates Momentus XT Hybrid an inexpensive addition for either a work drive or even a catalog.  If you're working on one set of files at a time.. then it's hybrid portion is enough to keep a smile on your face.  But you can easily overload the hybrid area and slow it down by moving through a lot of files in a short time.

I think.. most people use LR for processing (mainly) and light cataloging/viewing.  But some use it as a big catalog which is fine.. but then how you assign resources changes.

[Mark D Segal]

You may want to check the new Hitachi Sata-6 6GB/sec. drives. Not too expensive and I understand transfer rates very obviously outclass the 3GB models most of us are using, especially for retrieving, saving very large files. I don't have one yet myself, but I'm considering it.