Mac Pro Eight or Four Core?

[jlipkin]

Originally Posted by Noel_Carboni

Given the difficulty in upgrading computers - the physical change-out, porting data, reinstalling software, taking the time to set up the system just the way you like it, working out kinks in the new system... I always choose to buy absolutely top of the line cutting edge workstations, so that I can maximize the time before I have to do it again.
-Noel

True, but how much extra time will I get from the higher-end machine? It looks like it's only a bit faster, and will cost almost 30% more. I've had my g5 since 04, so that's 3.5 years. I'm trying to restrict my upgrades to major shifts (g4 to g5, g5 to intel, etc)


And I've never found upgrading my Mac particularly difficult. There's a feature that migrates all your data and applications from the old machine. Worked perfectly when I upgraded my laptop.

[Martin_Doudoroff]

Originally Posted by Noel_Carboni

I'm always surprised that some of Photoshop's functions are less than efficient on multiple cores... How hard is it to divide up an image into sections and assign each to a separate thread? Image processing lends itself well to multithreading.

1) Photoshop's code base is very old and tortured. It's a miracle that any multiprocessing is possible with it.

2) There is nothing much easy about writing multithreaded image processing algorithms. It's one thing to have the computer juggling multiple unrelated tasks, but when you have to act upon the same overall data AND realize any performance benefit in the process...

[jlipkin]

Originally Posted by Martin_Doudoroff

Interesting. I originally was running SoftRaid and also using FirmTek's eSATA card to hook up additional external drives. Last week, I disassembled all of that and am now running a very straightforward system without any RAID and no external drives. Frankly, while my fancy configuration worked great under Tiger, it was unstable under Leopard, and I decided it was too risky to continue as I was. In theory, the FirmTek drivers will stabilize in coming months and SoftRaid is constantly evolving, but I'm not interested in risk. What I will advise you is to immediately lower your expectations: if you anticipate trouble with your storage plans, you may still get frustrated, but at least you'll expect it!

Ha. Lower the bar, but good point about drivers and leopard.

I've found that my bridgeboard works fine under Leopard. You moved all your drives internally. Are you concerned about redundancy? It's not clear from your post what level of RAID you were running.

[Martin_Doudoroff]

Originally Posted by jlipkin

Ha. Lower the bar, but good point about drivers and leopard.

I've found that my bridgeboard works fine under Leopard. You moved all your drives internally. Are you concerned about redundancy? It's not clear from your post what level of RAID you were running.

I had two RAID 0 volumes running internally: one for data and the other for backup (very short term incremental backups to hedge against user error). Then I had rotating archives going with external eSATA units. Everything was choreographed with ChronoSync. Worked pretty flawlessly under Tiger. Under Leopard, I was seeing occasional read errors on my RAID 0 volumes and seeing occasional file i/o lockups when the external drives were operated: the kind of stuff that leads to premature aging. As far as I know, I have lost no data at all, but something was clearly amiss. I think this time 'round I'm going to set up Time Machine to backup everything except my photography work and try to get ChronoSync working again for all the photo stuff. (I don't trust Time Machine around Lightroom.)

In principle, I might be well-suited with a RAID 1 array for everything but archiving, but I'm a little spooked at the moment. Risk of loss of short-term work is a generally a lower priority for me than long term data preservation/archiving. Regardless, I'll be very interested to hear a report from you about what ends up working (or not) for you.

One other thing has really irritated me: I find the external eSATA cable interconnections to be pretty poorly engineered. It seems if two or three molecules of air are disturbed around these cables, a drive could suddenly pop off-line. There aren't very many situations I can think of where that would be considered a "good thing". Anybody else seen this problem? (I know others who have outside this forum.)

[Jerry Skrocki]

Originally Posted by Martin_Doudoroff

There's really nothing wrong with the first generation Mac Pros. If you can save a pile of money by buying one of those instead of the new edition, it might not matter one bit. I don't really know enough about your specific requirements to make strong judgements. I can say I've found my dual dual-core 2.66Ghz Mac Pro more than adequate for work with 12 megapixel imagery. I have 4GB of RAM which is more than Photoshop will use, anyway. If I had 8GB or RAM, I could leave Lightroom and various other apps running all the time without worrying about virtual memory getting involved. But so far, I haven't been motivated to add more (I was careful to leave four open memory slots so upgrading would be as cheap and easy as possible.

On a MacPro, Photoshop CS3 can utilize up to 8 gigs of ram. It uses 3.7 gigs directly and any additional ram (up to 8 gigs) is used as scratch disk before actually going to the hard drive.

I believe that adding more RAM is the most important upgrade you can make for Photoshop (rather than a 4 to 8 core upgrade or raid setup).

This Adobe Tech Note describes memory use of CS3 and Mac:
View Document

Jerry

[jlipkin]

Jerry, I'm much more interested in the performance of Lightroom at the moment. I should have mentioned this earlier, but the discussion went in a different direction. I find the lag when scrolling in grid view to be absolutely appalling, and I find it actually even a bit faster on my MacProBook.

Good to know about the extra RAM being used as a scratch disk.

Thanks for all the great advice. I'll update everyone when I get the machine.

[Martin_Doudoroff]

Originally Posted by jlipkin

Jerry, I'm much more interested in the performance of Lightroom at the moment. I should have mentioned this earlier, but the discussion went in a different direction. I find the lag when scrolling in grid view to be absolutely appalling, and I find it actually even a bit faster on my MacProBook.

Jonathan, I don't know how much lag you're experiencing, but here's what I get on my Mac Pro:

I have about 3000 photos in the library (all with 1:1 previews) at the moment. If I hide the menus (tab), I get about 7x4 cells on screen. Whenever I scroll, Lightroom displays very low resolution thumbnails, and it consistently takes just under two seconds to redraw all 28 at "full" thumbnail resolution. Page up/page down produce quasi-smooth scrolling, but the frame rate is so poor that it isn't very convincing. Scrubbing the scroll bar is fairly responsive unless I pause long enough for it to start painting in the "full resolution" thumbnails: once that starts, the scroll bar still moves but the grid doesn't budge again until the redraw completes.

This performance is not far from what I see in iPhoto when scrolling around its grid, similarly configured. The main difference is that iPhoto is better at interrupting whatever its doing to scroll: the grid doesn't get stuck if you scroll while it was painting those "full resolution" thumbnails.

Does this sound good or bad to you?

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