"same generation?" I'm talking about what you can buy today.
The 8800GS is really an 8800M GTS, and yes, it's close to twice as fast in 3d gaming. Not so much in apple's pro apps, but that's a driver problem; the hardware is there.
The 7200 RPM laptop drives are still 2.5" and don't perform as well as a real desktop drive.
What exactly are you going to put in to a $700 desktop to make it so much faster than an imac? A quad-core? Yeah, great, but how many applications is that really going to help you in yet? A desktop graphics card? Again, great, but if you want something that outperforms the 8800"GS" it's going to be pretty pricey. Other than that, what components are you going to use to make it such a superior machine?
That's what I meant by same generation. Current MBP to current iMac.
Sorry, I got confused on which cards were in each. Yes the 8800 series is considerably faster than any 8600 card. In 6 months though it will make little difference. As a laptop user I've come to the realization it doesn't matter what graphics card I order my machine with.
3.5" drives may be faster generally, but not necessarily.
http://www.digitaldingus.com/articles/2005sep/25dilemma.php
2.4 Core 2 Quad - $200
4gb - $75
decent mobo to allow OC to 3.0 GHz $100
HDD - $100
8800 GT - $150 This card is, relatively, VERY cheap, and faster than the GS
$75 for a good power supply
XP Pro license from school (or Leo, or Ubuntu)
Of course this can be cut back/changed for what's needed, but since I mentioned video encoding I think the step to quad is the single most important thing.
Ya most people don't nee quad. Heck, they don't need dual for that matter. I seem to remember people saying dual cores were pointless. Unless your doing something demanding that doesn't thread well, the extra clock speed is just as worthless.
My point was that the iMac doesn't have enough advantage over the MBP to make it worth it, UNLESS you don't need a laptop. Reasoning being that, other than the hdd, it's basically a laptop.
I guess I've been a hardware geek for too long.