Thanks for the replies, all!

@tfdesign Yes, the CoreDuo- just before they introduced the Core2Duo. So it's a 32bit machine that maxed out at 2GB RAM, enough for me to upgrade her to Snow Leopard last year, but she's cut off from upgrading to Lion. You're right, any machine I buy will see a dramatic performance increase over her existing machine.

I'm going to take it for granted that I want to get the $1999 iMac that comes with the Radeon6970M with 1GB graphics memory, since all the other iMacs only have 512MB graphics cards, and the processor is capped at 2.7GHz.

So here are the options available for customization, I guess more than anything I'm looking for a sense as to which of these things will be worth the upgrade-

$200 to go from 3.1GHz Core i5 to 3.4GHz Core i7
$100 to bump the graphics memory from 1GB to 2GB
$210 to go from 4GB to 8GB RAM (which I know I can buy cheaper elsewhere)

Thanks again everyone.

Well, first of all, part of this is that her machine seems to be on the outs. I haven't been able to get it to boot, even from a SnowLeopard DVD (thank goodness for TimeMachine backups!). But the machine is maxed out at 2GB of RAM, and unfortunately is just under the line for upgrading to Lion (which we want for shared iCloud calendars, etc...)

But yes, she does render. Her landscape firm has been using sketch up for presentation along with DynaScape(?) for the details.

From my experience in video applications, the graphics card gets you the real time OpenGL performance, and the processor is for rendering tasks. And more RAM is always good. Is this the same with Sketchup?

Reading these forums for the last hour, I see lots of threads about problems with the Radeon cards, though someone suggested in one thread that the problem isn't what it used to be. Is this still a problem? What effect does it have on running the software?

Thanks

Hey All,

My wife's 2006 CoreDuo iMac is getting a bit long in the tooth and so we're looking to upgrade her to a new machine. She uses Sketchup but I'm the technical one, so I'm here to query on how best to spend the money on a new iMac.

My question to you all is what's most important for Sketchup performance?

Is it going to from the 3.1GHz i5 to 3.4GHz i7 processor?
More RAM?
the better Radeon HD6970M Graphics processor that you can only get with the top 'o the line 27" iMac, is the extra $100 for the 2GB of graphics memory worth it?

My wife says she could probably live with the 21.5" display, but you can only get the Radeon 6770M with 512 graphics memory.

So, what makes the most difference in performance? What's the best place to put the extra money? Or is the stock configuration iMac27 with 3.1GHz Corei5, 4GB RAM, and the Radeon 6970M with 1GB graphics memory suitably beefy?

Since I don't use the program myself I'd appreciate any guidance.

Thanks much,

M