VRAM and rendering previews in Lightroom..?

[Overgaard]

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Here's a question not even staff in the Apple stores seem to be able to answer:

 

My one and only speed limit on the MacBooks is the previews in Lightroom.

 

So I've been looking at which MacBook Pro to get of the new ones, or eventually go back to the 15" 2,5 Ghz alu version with 512 MB VRAM which worked quite well.

 

In examining the computers eyesterday (using Aperture), the new Air took 2 seconds to render a preview, and the 17" MacBook Pro with 512MB VRAM took 1 second!

 

Now, then we got into that the 512MB VRAM is only in use when you turn it on, and for battery purposes it seem this is only possible when the computer is plugged into a power outlet (which then makes the previous 15" and 17" alu version with 512 MB VRAM a better choice).

 

So does anyone have the knowledge about which power the Aperture and Lightroom use to generate the previews. How much does it depend on the RAM, graphic card or VRAM?

[spylaw4]

Thorsten - have you asked this question over on the LR forums? IIRC there was one that was moderated/monitored by LR and answers given.

[lesh]

There seems to be a lot of comment around about how to extract the best LR performance from a MBP.

So many viewpoints, and the answer seems far from clear.

For example this website : Macintosh Performance Guide: Optimizing Your Applications ? Adobe Lightroom - suggests, amongst other things, that "The late-2008 and mid-2009 “unibody” models offer little or no performance advantages over the prior models." This reviewer and others also suggest that, giving LR 2 concurrent tasks brings both cores in the MBP into play, to maximum effect. A prevailing theme is that, unless portability is essential, the latest MacPro is the real answer for performance, even although LR is not yet written to take full advantage of it's multi core architecture.

Seems to be implying that LR should be written to make use of 8 or 16 cores and that laptops should be so equipped. (Be prepared to update your hardware every 18 months?)

Me?, I'll just muddle along with my existing kit until I can hear of a model offering a solution I can understand.

[Overgaard]

Thanks, according to that it is not going to work without bugs till they update Lightroom and I have 8GB in my laptop. Funny they don't mention VRAM at all.

 

I tried to change my previews to 100% in import but that brought Lightroom to its knees. But importing as 100% previews should handle the actual waiting for previews for each photo in a long series (which is the big problem when Im in the field and has to select and send asap).

[lesh]

I'm definitely not a guru on this stuff but believe I've read here and there that, while VRAM is critical for video work, it's not so important when working with static images. Maybe there's someone around with the technical expertise to confirm if that's so?

[dfarkas]

Thorsten,

 

My understanding of how Adobe is using GPU acceleration has less to do with how much VRAM the GPU has, but more to do with how many graphics cores or ALUs it has, the clock speed, memory bandwith, and the memory interface. While VRAM does have some impact on performance, it usually dictates how much resolution (or how many monitors) a graphics card can support.

 

The Air uses an Intel X3100 integrated graphics controller, for which I can't seem to locate how many cores it has, just that it shares memory with the CPU (slow), The MacBook Pro 15" uses a 16-core Nvidia 9400M and the 17" uses the same 9400M plus an additional 32-core 9600M GT depending on need (power savings/performance). Nvidia offers CUDA optimizations, which Adobe uses in CS4. I don't believe Intel supports this.

 

I opted personally for a laptop with an Nvidia FX 3700M, which uses 128 cores and 1GB VRAM. My Adobe applications do feel very fast and my Lightroom previews render quickly (the quad-core CPU, and dual SSDs don't hurt either). But, my battery life is abysmal. I'd get 4x the battery life on the MBP. The graphics card alone is pulling more power than an entire MBP at 75W! Such is the price for ulitmate speed.

 

Good luck, but know that small size, light weight, great battery life and performance in a notebook don't always go together. You're going to have to make some compromise along the way.

 

David

[John Thawley]

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You're going to have to make some compromise along the way.

 

David

 

I just hate that about life.