iMac vs. PowerMac--stats vs. real world use

[mikeseb]

Apologize if this is the wrong place for this query.

My situation: I have a creaking 4-yr-old Dual G4 1.42 GHz PowerMac tower that I plan to replace this year. It takes forever to do anything with this computer, it's so slow. I will probably run MacOS Server on it and use it for storage, etc. The question is, what to replace it with?

At least in theory the current PowerMac towers are awesomely powerful, and have the major advantage of being able to accomodate scads of RAM. However, they are pricey and large, and relatively noisy.

I've always assumed that for heavy-duty image processing I'd be better served by a PowerMac than by an iMac, but I'm rethinking. Their performance numbers seem pretty strong, and even the largest 24" screen model would probably save me a bunch of cash over a tricked-out PowerMac tower.

The one immediate problem I see is that, as far as I can tell, the top-end iMac can accomodate "only" 3 gigs of RAM. I regularly work with image files of 1.2 to 1.5 gigs (scanned MF film) and expect that during this computer's lifetime I'll be using large files from whatever MF digiback or hi-megapixel camera I own in the near future. I also usually have iView open along with Photoshop and now, probably Lightroom as well, along with a web browser.

As for HDD, the iMac's current largest drive is 750GB; this is less of an issue because I expect to use external storage of some sort anyway as part of a storage/backup redundancy setup.

Stats and numbers aside, what is your experience with these machines doing the sorts of things i describe? Is an iMac going to do the job for me or do I need to spring for the P-Mac?

Thanks in advance.

[afremiotti]

If this is going to be your main machine to work on I would say get the tower. I have both Imacs and towers and there is a lot of difference between them.

The Imacs are good with one or two applications open but not much more and they are decent for retouching even big files but don't do nearly as well processing large amounts of files. They are nice to travel with as the whole thing fits in one case and sets up quickly on location or a hotel room.

The towers on the other hand are much faster, and they can be expanded a lot so they are more useful longer. It's nice to have more than one hard drive as well, one for applications and scratch and one for everything else. They also seem to be built much better. My Imacs are breaking down all the time.

Be sure to get Apple Care either way If you use it everyday and ever take it on location any computer will eventually break down. An Imac will probably go down a couple of times per year, but at the cost you could get two for the same price as a good tower.

[GregW]

Hi Mike, You pose an interesting question.  I have a similar dilemma.

I think the answer lies in your depreciation timeline.  

By switching to a 24" Intel iMac you are going to get an instantly noticeable performance improvement.  Once CS3 is available you are going to get another performance improvement.  Macworld quoted twice the speed for a sharpen or blur filter on a 2GHz MacBook Pro Core Duo when using the CS3 beta over CS2.  As long as your current requirements don't change too much over the next 18 months you'll probably be satisfied.  A concern about an iMac in your situation is the display.  It's purely anecdotal but it seems that as production volumes have increased so has the variability in display quality.  You've already indicated that the 3GB RAM limit is a constraint.  I'm inclined to agree in the mid term.

Even with a higher starting price The Mac Pro may prove a little cheaper in the longer term because it's probably got 3-4 years of life in it with the upgrade potential it offers.  You are free to use your existing display or pick up a new one.

If you want a stop gap for 18 months then I think the iMac is a nice option.  Otherwise you are probably best biting the bullet on a Mac Pro, it will probably be cheaper in the long run and offer more flexibility.

Regarding quality and reliability.  I've had a different experience to the previous poster.   My G5 tower and G5 iMac have been exceptionally reliable.  My Cube was very unreliable, so maybe I got lucky with the G5 kit.  The only negative of the G5 tower is the noise imo.

When the next Mac Pro update comes I'll pick one up for the heavy lifting.

[tedchoi11]

Hi Mike, You pose an interesting question.  I have a similar dilemma.

I think the answer lies in your depreciation timeline. 

By switching to a 24" Intel iMac you are going to get an instantly noticeable performance improvement.  Once CS3 is available you are going to get another performance improvement.  Macworld quoted twice the speed for a sharpen or blur filter on a 2GHz MacBook Pro Core Duo when using the CS3 beta over CS2.  As long as your current requirements don't change too much over the next 18 months you'll probably be satisfied.  A concern about an iMac in your situation is the display.  It's purely anecdotal but it seems that as production volumes have increased so has the variability in display quality.  You've already indicated that the 3GB RAM limit is a constraint.  I'm inclined to agree in the mid term.

Even with a higher starting price The Mac Pro may prove a little cheaper in the longer term because it's probably got 3-4 years of life in it with the upgrade potential it offers.  You are free to use your existing display or pick up a new one.

If you want a stop gap for 18 months then I think the iMac is a nice option.  Otherwise you are probably best biting the bullet on a Mac Pro, it will probably be cheaper in the long run and offer more flexibility.

Regarding quality and reliability.  I've had a different experience to the previous poster.   My G5 tower and G5 iMac have been exceptionally reliable.  My Cube was very unreliable, so maybe I got lucky with the G5 kit.  The only negative of the G5 tower is the noise imo.

When the next Mac Pro update comes I'll pick one up for the heavy lifting.
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i've also had good luck with iMacs. but i also had great luck with my cube, and held onto it much too long. i'm not sure i'd put much weight on a MacPro benefit that is realized 1.5-3 years from now. if you're not uncomfortable with ebay, i'd think that a 1.5 year old iMac would hold much of its value and you could afford to do a more rapid upgrade cycle. used MacPros hold less value because its users tend to put more value on power.

for me, the key issue would be (1) ram capacity (2) reliability. power and usability are fine- the imac is quieter, and with external monitor and storage, seems very flexible.

[mikeseb]

...The Mac Pro may prove a little cheaper in the longer term because it's probably got 3-4 years of life in it with the upgrade potential it offers....  You are free to use your existing display or pick up a new one.
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Interesting feedback from both respondents--thanks much.

When you talk about upgradeability with the Mac Pro, do you mean something beyond the ability to add more RAM and more/newer/faster hard drive capacity? It seems like these are the two main areas in which the iMac is limited in its upgrade capacity, yes? I suppose also the ability to add SATA external drives would be another.

I realize of course that external HDD performance is slower than that of internal HDD's. I have about 750GB internal HDD in my current machine, with 500GB of that as twin SATA 250's, plus a couple of older drives; my strategy has been to keep active files that I'm actively working on on the internal drives, and move the other stuff to externals after backing up to DVD and/or additional HDD's. (I see a storage tower/NAS in my future.)

[GregW]

When you talk about upgradeability with the Mac Pro, do you mean something beyond the ability to add more RAM and more/newer/faster hard drive capacity? It seems like these are the two main areas in which the iMac is limited in its upgrade capacity, yes? I suppose also the ability to add SATA external drives would be another.

For the most  I mean exactly that.  Particually the RAM which together with the display I see as the biggest disadvantages of the iMac in your situation.  

It may also be possible to upgrade the processors.  http://www.anandtech.com/mac/showdoc.aspx?i=2832&p=6