Quad-core for Lightroom?

wellman · June 28, 2007

On 7/22, prices on the quad-core Intel Q6600 are set to drop to around $270, which has me thinking about a new system. Can anyone tell me whether Lightroom uses all four cores? Thanks.

Manfr3d · June 29, 2007

I've seen users report 300% cpu usage with lightroom
which would suggest that it can utilize at least 3 cores.

Reference: http://forums.whirlpool.net.au/forum-replies-archive.cfm/562887.html
(near the bottom)

Other reviewers of Lightroom also suspect that lightroom
uses multiple coors:

Reference:
http://www.designpreference.com/reviews/software/lightroom1.html
(mid article)

.. but if you want to know for sure i suppose you
could send adobe support an email with your specific
question.

wellman · June 29, 2007

Manfr3d wrote:

I've seen users report 300% cpu usage with lightroom
which would suggest that it can utilize at least 3 cores.

Reference: http://forums.whirlpool.net.au/forum-replies-archive.cfm/562887.html
(near the bottom)

Other reviewers of Lightroom also suspect that lightroom
uses multiple coors:

Reference:
http://www.designpreference.com/reviews/software/lightroom1.html
(mid article)

.. but if you want to know for sure i suppose you
could send adobe support an email with your specific
question.

Thanks for the links. I think I will fire off a note to Adobe, and if they respond, I'll post here.

CatOne · July 2, 2007

wellman wrote:

On 7/22, prices on the quad-core Intel Q6600 are set to drop to around $270, which has me thinking about a new system. Can anyone tell me whether Lightroom uses all four cores? Thanks.

4 cores?

pffft.

wellman · July 2, 2007

CatOne wrote:

4 cores?

pffft.

That's pretty sweet. So, does Lightroom use more than two cores?

colourbox · July 2, 2007

wellman wrote:

On 7/22, prices on the quad-core Intel Q6600 are set to drop to around $270, which has me thinking about a new system. Can anyone tell me whether Lightroom uses all four cores? Thanks.

I have 4 cores (2 dual Mac Pro) and it definitely uses more than one, especially if you get it going on parallel operations. But it is misleading for the earlier post to say 300% = uses 3 cores. That's not how it works. My CPU meter seems to indicate that it tries to use portions of every core. If Lightroom was using "300% CPU" on my Mac, it would show up as 75% (more or less) usage of each of the 4 cores.

In addition, since not everything can be parallelized, you're not going to see 4 cores be 4x as fast as 1 core, and you definitely will not see 8 cores be 8x as fast as 1 core, to the point where I'm glad I don't care about having to save up for the 8 core. Not for working on single images, anyway. Just not worth it. If I was doing video or something where CPU really is the limiting factor, then oh yeah, you bet.

wellman · July 3, 2007

colourbox wrote:

I have 4 cores (2 dual Mac Pro) and it definitely uses more than one, especially if you get it going on parallel operations. But it is misleading for the earlier post to say 300% = uses 3 cores. That's not how it works. My CPU meter seems to indicate that it tries to use portions of every core. If Lightroom was using "300% CPU" on my Mac, it would show up as 75% (more or less) usage of each of the 4 cores.

In addition, since not everything can be parallelized, you're not going to see 4 cores be 4x as fast as 1 core, and you definitely will not see 8 cores be 8x as fast as 1 core, to the point where I'm glad I don't care about having to save up for the 8 core. Not for working on single images, anyway. Just not worth it. If I was doing video or something where CPU really is the limiting factor, then oh yeah, you bet.

Thanks for your response. Out of curiosity, what happens to your CPU usage when you're in the develop module and you're sliding something relatively compicated back and forth (say the v1.1 sharpening masking control, which builds a custom edge mask on the fly)? It makes sense that LR should use multiple cores when doing something obviously parallel (like exporting photos), but I'm hoping it breaks single images up into chunks in the develop module. Thanks again.

colourbox · July 3, 2007

wellman wrote:

Out of curiosity, what happens to your CPU usage when you're in the develop module and you're sliding something relatively compicated back and forth (say the v1.1 sharpening masking control, which builds a custom edge mask on the fly)?

I never really looked at that because I usually hide the menu bar, but decided to check it out. Here is a shot of the MenuMeters (free) CPU meter in my menu bar while dragging sliders like Fill Light and the new masking sliders in LR 1.1. on an 8MP SLR raw file. It's the four gray lumps in the middle of the menu bar display. Looks like it peaked at approximately 200% usage (50% x 4). It goes higher during a big export.

Assuming that the reporting and display are accurate, it looks like all four cores get roughly even distribution. Maybe that means I'm wrong about the 8-core not helping.

wellman · July 3, 2007

colourbox wrote:

I never really looked at that because I usually hide the menu bar, but decided to check it out. Here is a shot of the MenuMeters (free) CPU meter in my menu bar while dragging sliders like Fill Light and the new masking sliders in LR 1.1. on an 8MP SLR raw file. It's the four gray lumps in the middle of the menu bar display. Looks like it peaked at approximately 200% usage (50% x 4). It goes higher during a big export.

Assuming that the reporting and display are accurate, it looks like all four cores get roughly even distribution. Maybe I'm wrong and an 8-core would help after all.

Thank you so much for the information! This is exactly what I was hoping to see. Looks like saving up for that quad-core chip will be worthwhile after all.

Manfr3d · July 4, 2007

colourbox wrote:

I have 4 cores (2 dual Mac Pro) and it definitely uses more than one, especially if you get it going on parallel operations. But it is misleading for the earlier post to say 300% = uses 3 cores. That's not how it works. My CPU meter seems to indicate that it tries to use portions of every core. If Lightroom was using "300% CPU" on my Mac, it would show up as 75% (more or less) usage of each of the 4 cores.

In addition, since not everything can be parallelized, you're not going to see 4 cores be 4x as fast as 1 core, and you definitely will not see 8 cores be 8x as fast as 1 core, to the point where I'm glad I don't care about having to save up for the 8 core. Not for working on single images, anyway. Just not worth it. If I was doing video or something where CPU really is the limiting factor, then oh yeah, you bet.

I was just echoing what the other person wrote in the links i stated.
But your post makes me wonder. It seems that different cpu stat
tools seem to (just) display core usage differently. Some tools state
100% load as one core full load whereas your cpu tool (as well as mine)
seems to display 25% when one core is under full load on a 4 core system.

Quad-core for Lightroom?

Comments