Mac Pro Eight or Four Core?

[jlipkin]

Martin -

That sounds slow. I'm getting better performance on my MacBook Pro. I've only got about 1200 images, but I don't think that should affect performance much. My re-draw is almost instant now.

If you leave LR open for a while (a couple of hours) it will do a lot of rendering in the background. When I first launched LR, I got about the performance you did. After leaving it open for about fifteen minutes, the performance improved, especially after having scrolled through all of the images. From what I've heard, thumbnails get rendered in the background. I forgot to watch Activity Monitor but I suspect that's where you would see this happen.

[Martin_Doudoroff]

Originally Posted by jlipkin

Martin -

That sounds slow. I'm getting better performance on my MacBook Pro. I've only got about 1200 images, but I don't think that should affect performance much. My re-draw is almost instant now.

If you leave LR open for a while (a couple of hours) it will do a lot of rendering in the background. When I first launched LR, I got about the performance you did. After leaving it open for about fifteen minutes, the performance improved, especially after having scrolled through all of the images. From what I've heard, thumbnails get rendered in the background. I forgot to watch Activity Monitor but I suspect that's where you would see this happen.

Interesting. Over the last day or so, I've been tampering with Lightroom to try to optimize it any way I can and I'm not seeing much change, nor am I seeing any background activity. I already have 1:1 previews of everything in the library rendered, so it seems there's nothing left to render.

Either we're not actually talking about the same aspects of performance, or there's something about my configuration that's affecting Lightroom's behavior. I doubt there's any single aspect of my Mac Pro that it is "slower" than your laptop, but that doesn't tell the whole story. For example, I'm running at 1920x1200 and perhaps the video driver or the ATI X1900 XT have limitations that could come to bear on Lightroom's redraw speed?

I'll do some research over at the Adobe forums.

[Martin_Doudoroff]

More on library redraw speed:

There seem to be two main factors that affect redraw speed in Lightroom's Library:

1. The size of the thumbnails
2. The quantity of thumbnails to be displayed simultaneously

This makes sense.

The larger the thumbnails, the more pixels need to be painted, and the more image data has to be sampled to do so. Consequently, if you have really large thumbnails, then Lightroom actually makes multiple passes (as many as four) to fully render them. If you have really small thumbnails, Lightroom only needs two passes, and the second pass is just for overlays. The reason Lightroom makes passes at all is that it is distributing its work across the screen as evenly as possible. Otherwise, each image would sequentially render from upper left to lower right.

The quantity of thumbnails is a performance factor because of the number of cases that have to be handled, regardless of how large the thumbnails are.

The most responsive scrolling in Lightroom will happen when you use very small thumbnails AND the Lightroom window is as small as possible. If you run Lightroom on a large, high resolution display and use large thumbnails—what I do—you're looking at a near-worst-case scenario.

Interestingly, the worst case scenario is not necessarily when you have the largest thumbnail size set! As the thumbnails get really large, they really cut down on the quantity of thumbnails being displayed, so under some circumstances, you'll see faster redraws at the largest thumbnail settings than some of the middle-range sizes.

You can easily reproduce all this yourself in Lightroom simply by trying different combinations of these factors:
1. thumbnail size
2. window size (leave full-screen mode to freely resize the window)
3. toggling the side menus on and off (tab)
4. compact vs. expanded cells

[Jerry Skrocki]

I tried Lightroom and just did not care for the program. It seems like it is a rushed and unfinished response to Apple's Aperture program which directly utilizes the GPU of the video card allowing for very fast screen redraws. Aperture is also a database program with comparable features to Lightroom plus the added advantage of dual monitor support.

[Martin_Doudoroff]

Originally Posted by Jerry Skrocki

I tried Lightroom and just did not care for the program. It seems like it is a rushed and unfinished response to Apple's Aperture program which directly utilizes the GPU of the video card allowing for very fast screen redraws. Aperture is also a database program with comparable features to Lightroom plus the added advantage of dual monitor support.

While you're clearly in a minority with regards to your overall comparative assessment of these two products, I am very happy that both products exist and are finding a marketplace. I desperately hope Apple maintains a strong commitment to Aperture. Aperture has enormous potential and some delightfully ambitious thought behind it. Most crucially, a healthy competition is desperately needed if this new breed of tool is going to reach maturity.

[jlipkin]

Originally Posted by Martin_Doudoroff

More on library redraw speed:

There seem to be two main factors that affect redraw speed in Lightroom's Library:

Fascinating. I'll do some testing and get back to you. Big website to launch monday...

PS, Martin, in you research did you find out if rendering previews was disk-intensive, processor intensive, or done by the video card?

[Martin_Doudoroff]

Originally Posted by jlipkin

Martin, in you research did you find out if rendering previews was disk-intensive, processor intensive, or done by the video card?

To my knowledge, unlike Aperture, Lightroom does not make any use of a display adapter's processing capabilities. Rendering is done by accessing thumbnail caches on disk and scaling them with the microprocessor. There must be some more detailed information on this, somewhere, but I haven't found it, yet. I'll try to do a more thorough search of the Adobe forums and see if there's any info buried in there.

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