I'm a LR user since the week LR 1.0 was released but have thus far only used low end computer systems since I had been doing photography as a hobby. Well, these days I'm actually running a business and dealing with mass quantaties of photos on a weekly basis as well as a master catalog containing 89k photographs (the actual .lrcat file size is 1.3GB).
Currently I'm using a 2010 13" MacBook Pro w/ 2.4GHz Core 2 Duo, 4GB RAM and a 5400rpm, 250GB HDD. My catalog file of 1.3GB, its 47GB previews file and all 500GB of photos reside on a 5400rpm, 640GB external HDD dedicated to this purpose. Oh and it's connected with USB2. As you might have guessed, this is somewhat slow in that it takes minutes for the catalog to first load up and show all folders / thumbnails, and there are noticeable delays in flipping in between images. Slow export speed is not a big deal for me, and the functions within LR, e.g. develop tools, etc., are not slow in any way.
Though I am considering purchasing a used 27" i7 iMac and upgrading to a 7200rpm HDD, OWC 128GB SSD and 16GB RAM, I am also considering a WIndows machine solely due to the lesser cost involved and greater flexibility in configuring HDDs. With this in mind, what should I be looking at? Currently I'm thinking about a quad i5, relatively low end GPU (unimportant, right?), 16GB RAM, 1TB, 7200rpm HDD for my digital negatives and either a single SSD or striped RAID totaling 120 or 128GB for the operating system, LR program, catalog file and previews file. Am I on the right track here, or...? Granted, by the time you factor in that fantastic 27" screen (I don't own a monitor and would otherwise purchase a Dell 2407 or 2408) the cost of doing a Windows machine matches that of a slightly used iMac.
Also, AMD processors work great.
The biggest thing (regarding abnormal performance) is how well Lightroom likes your hardware/software configuration, which unfortunately is not very predictable.
i.e. some people on high-powered computers cut through raws like butter, other people with the same hardware have the worst performance of all...
So, sometimes it's the hardware/drivers, and sometimes its software/services/config/order-various-software's-are-installed kinds of issues, when performance is abnormal I mean.
Also beware: Lightroom does some things fast and other things slow, due to software design/implementation, even when it's operating at peak performance level.
But in general, it sounds to me like you are on the right track. Except, if you are most familiar with Macs, consider getting a Mac, and vice versa (cost difference should be the least of your concerns, unless you don't value your time much, or user experience...). From the best I can tell, performance problems are not identify-ably better or worse on one platform versus the other - somebody please correct that statement if it's wrong.
I bought a quad core mac mini server in January to get the quad core & dual 7200rpm HDD (I upgraded one to a SSD) & obtained 8GB RAM separately to upgrade myself - LR4 runs fine on that. It replaces a 9 year old dell PC running XP.
Still using the 17.5" dell monitor from my old PC - will upgrade this at some point to a larger screen - probably one of the Dell 23" ones
Thanks guys! Actually this is going to have OS X on it, so I guess you could call it a Hack Pro. Pretty reliable and easy to do these days!
My outstanding questions at the moment are as follows:
Now about the monitor, as I would like something at least somewhat good. The screen on my MBP is beautiful aside from the fact that it's glossy. But for a desktop it's been my understanding that a Dell 2407WFP, 2408WFP or the NEC PA241 would be a fantastic choice. Does anyone have any comments on these, whether it'd be better to spend $600 on the NEC instead of $300 on the Dell (used prices), or whether there are different monitors I should consider?
The information at this post should be helpful:
The OP at the above link is building his own system, but the configuration information is relevant to any OEM system, PC or Mac.