Minimum System Requirements

Question

I am wondering if I can upgrade to OSX 10.5 Leopard. I have a first gen flat-panel iMac with a Power PC processor. It's only an 800 MHz G4, but I have 1024 MB of RAM. I know that Apple recommends a minimum 867 MHz G4 processor and 512 MB RAM, so I am just a bit under the minimum processor speed, but I have 2x the recommended RAM.
Has anyone with an 800 MHz iMac tried to run OSX 10.5? If so, will it work? Any problems? Or, should I just try to upgrade to OSX 10.4? (I'm still running OSX 10.2.8 Jaguar)
If the current release of 10.5 won't work, does anyone know if the next release (Snow Leopard) will work on my computer? I understand it is being made smaller and more efficient than the current release, so maybe it will need fewer resources to run correctly?
If I upgrade to either 10.5 or 10.4, I have a dual-partitioned hard drive. The smaller partition has 10.2.8 on it; the smaller partition has OS9 on it and a few OS9-only apps. Can I still keep this set-up if I upgrade? Will I still be able to dual-boot? Would I still be ablle to run in Classic mode within OSX?
Finally, if I upgrade, will I still be able to use any of my Jaguar-era apps (Microsoft Office for Mac, iLife, Photoshop Elements, etc.), or will I need to buy all new software?
Thanks.

Answer 1

The technical answer is yes you can, if you hack the OS a little bit to 'trick' it into not caring about your CPU speed.
But the responsible answer is that you're putting yourself in a bad spot. Here's why:
Your hardware is end-of-life. This means that Apple has carried drivers and tested against your specific model of Mac for driver development and performance in OS X since 2002 when your iMac was introduced. It was discontinued in February of 2003, and essentially lost Apple's support in October of 2007 when Leopard started requiring 867 MHz CPU's.
This means that Apple will no longer guarantee that they will include proper device drivers for your hardware, and that they won't go back and test on them for your model anymore. This might mean a driver change (particularly with video) could happen that breaks your Mac with Leopard at some point, and there would be no way to resolve it short of rolling back. Also, many new apps included with Leopard really depend a lot on CPU speed or hardware features you might not have, like DVD player which needs an Intel CPU pretty much in order to deinterlace well, or iChat which needs an iSight cam (not standard on he old iMacs).
You are also going to run into the fact that many apps are going Intel or 64-bit Intel and no longer compiling 32-bit G4 binaries anymore. Handbrake recently did this. While some folks are still getting some app lovin' for G5 64-bit, the PowerPC days are over, guys.
I look at it this way: you probably got a solid 6 years out of this iMac. You probably had OS X 10.1 all the way thru 10.4 with complete OS and app support. It has done its part well. If you're short on cash I recommend getting a used or refurb 1st-gen Intel iMac 17". They're not hard to find and they run everything modern.