# Which iMac video specs should I get for LR2????



## stayathomedad (Jun 24, 2009)

Which iMac setup would be best for PS/LR2 photo editing work?

The older ATI iMac has a real video card but tops off at 4GB... the Nvidia iMac has the newer shared memory card (boo) but can hold up to 8GB

Which one should I look at?

The ATI system has the 2.8 C2D processor with DDR2 (8''Mhz) memory that tops out at 4Gb -- and for video it has a ATI Radeon HD 26'' PRO with 256MB of GDDR3 memory

Or 

The Nvidia system has 2.66 C2D processor with DDR3 (1'66Mhz) memory that tops out at 8GB -- and for video it has a NVIDIA GeForce 94''M graphics processor with 256MB of DDR3 SDRAM *shared with main memory*


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## stayathomedad (Jun 24, 2009)

Is the 8GB over the 4GB really that important in comparing the video cards?

I've been told the Nvidia supports OpenCL which might play a part down the road... no?


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## Brad Snyder (Jun 25, 2009)

I'd think of those 2 choices, and considering LR alone, you'd want the 8GB and faster frontside bus. I can't say that the fractional GHz difference, or the 256MB shared memory video would have as much impact as 4 extra GB of faster RAM.

I'd say GPU direct application support is speculative, as far as LR's concerned. I haven't studied the details of the Photoshop/GPU integration, so can't comment.


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## sizzlingbadger (Jun 25, 2009)

I honestly don't think the graphics card makes a huge difference with LR. The images are stills, there is no video or 3D rendering like games. The GPU integration in CS4 works fine with the ATI Radeon card too.


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## stayathomedad (Jun 26, 2009)

Brad Snyder said:


> I'd think of those 2 choices, and considering LR alone, you'd want the 8GB and faster frontside bus. I can't say that the fractional GHz difference, or the 256MB shared memory video would have as much impact as 4 extra GB of faster RAM.
> 
> I'd say GPU direct application support is speculative, as far as LR's concerned. I haven't studied the details of the Photoshop/GPU integration, so can't comment.



Ya, but will LR really use up or take advantage of the extra/additional RAM over 4GB? In other words, Will I see some improvement in performance if I have 8GB instead of 4GB for RAW file editing in LR2?


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## Brad Snyder (Jun 26, 2009)

Need some Mac folks for that question. It's a valid question on Windows 32 bit systems, but I'm led to believe the Mac plays more nicely with big memory and 64 bit software. 
Perhaps that's not applicable to iMac?


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## stayathomedad (Jun 26, 2009)

oh mac folks... where art thou?


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## sizzlingbadger (Jun 26, 2009)

Not a Mac question but a general computer question really. 32bit systems will have limitations with the amount of RAM that is addressable.

In simple terms.....

Will LR use 8GB of RAM ? Only if it needs to which is unlikely for many people. You can only work on one image at a time in LR so there is plenty of time in the background for stuff to be written to disk / cached etc...

Photoshop can open many images at a time and that is where you will see the advantages of having large amounts of RAM.

Most apps have a 'working set' size and if you have enough RAM for that then adding more doesn't usually make a whole lot of difference. The working set size will vary on your workflow.

I have never seen LR use more than about 2GB on my 64bit system (different workflows will vary), but photoshop will eat everything you throw at it if you keep opening images.


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## Victoria Bampton (Jun 26, 2009)

stayathomedad said:


> Ya, but will LR really use up or take advantage of the extra/additional RAM over 4GB? In other words, Will I see some improvement in performance if I have 8GB instead of 4GB for RAW file editing in LR2?



On a Mac, I'd have said yes, particularly if you're running LR in 64-bit and you like having other programs open too.  I saw a noticeable difference going from 8gb to 14gb, and I've seen LR use a clear 6gb of that on occasion (building previews, running exports).  

What are you running at the moment?


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## Brad Snyder (Jun 26, 2009)

See, that's the response I was hoping for, I know lots of Mac folks running Lr with lots of memory, there must be a reason for it.


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## stayathomedad (Jun 26, 2009)

Victoria Bampton said:


> On a Mac, I'd have said yes, particularly if you're running LR in 64-bit and you like having other programs open too.  I saw a noticeable difference going from 8gb to 14gb, and I've seen LR use a clear 6gb of that on occasion (building previews, running exports).
> 
> What are you running at the moment?



I'll be buying an iMac, so I don't think I'll be using 64-bit...

Right now I'm using a 3 year old 13 inch macbook with a 2.' C2d and 2GB of ram (64MB shared video)


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## Victoria Bampton (Jun 26, 2009)

iMac and 64 bit should be fine as long as there's enough memory.  Once you top 4gb, there's often an advantage.


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## pknoot (Jun 26, 2009)

For photo editing, the key system limiting factor is the LCD monitor, not the video card!  Unless you invest in a component system with a very expensive high-performance monitor, you won't even come close to the color depth of the digital camera (14/16 bits vs 8 bits on the monitor, a very serious mismatch).  Therefore, the video card is mostly irrelevant for this application.  Even the amount of memory on the video card will not matter for photo editing, since the main work is done by system RAM (which does matter and should be maximized).  As pointed out, this all changes for video editing and gaming, where you need the biggest, baddest video card(s) you can afford!

In conclusion, if you focus primarily on photo editing on your iMac, invest your funds in system RAM and go with the simplest graphics card.


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## sizzlingbadger (Jun 26, 2009)

You don't need more RAM to run 64bit, it just allows you to make more use of RAM if you have more. I have 4GB RAM on my system and use LR and CS4 with out any memory issues (no swapping etc) purely due to the fact I don't run much else at the same time and my workflow is small being an amateur photographer, I rarely have more than 3-4 images open at once.

Victoria will be hammering her machine much more than I do and 14GB RAM will help in this case, especially if you have other programs open. It's about balancing the initial outlay and time (usually money).

It may take my machine 4' mins to re-render previews and Victoria's machine may do the same work in 3' mins, the question is do I care about the 1' mins ?  (not at the moment) Also do I care that my machine is sluggish in other Apps while it's rendering ? again for me it's not an issue but for others where time is money it may be.


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