[Surfer]

Today, I had a look at the new iMac! It's truly an amazing machine!! The screen is very bright and sharp!

Anyhow, I was amazed how zippy OS X felt on this machine (700Mhz G4), I then jumped over to a 600Mhz ibook and the difference was huge!! Apps took more than twice the time to open and all of a sudden the spinning disc was up and running like on my lombard powerbook. On the iMac I never even saw the spinning disc!!!

With such a difference in software optimization I guess it's only a matter of time before the iBook gets a G4! Personally I am leaning more towards a PowerBook G4 as its a whole different story now that I am using OS X instead of OS 9.

Anyone else have any experiences with G3 vs G4 in OS X?

[macusrX]

it is interresting you ask this..... i do not really notice huge differences at all. i havea 600MHz iBook at home and a 800 MHz PowerMac at work.... X seems just as quick on my iBook as it does at work. i know for most this is not true. and in application sppeds you will notice difference but in most functions i really do not notice it...

[juanvaldes]

yes the difference is night and day.

But I am amazed at how well our 333G3 iMac holds it's own to my dual G4.

[petej]

I wonder what amounts of RAM were installed in the iBook and the iMac. Too little RAM makes OS X slow to a crawl, and my opinion is that OS X can't run acceptably in less than 384MB. If the iBook had the stock 128MB in it, that alone could account for the speed difference (assuming the iMac had more).

[Loco Bozo]

Launching applications has little to do with processor speed. It is very dependent on HD speed, and not suprisingly, a desktop HD is much faster than a laptop HD.

I don't think you're really measuring the differences between a G3 and a G4 in your test.

[hamiltondj]

As the user of several machines - g3 and g4 I think the following is true regarding OS X:

A G4 with 256 MB is the optimal machine to run OS X (Even more memory is better)

A G3 with 500+ MB runs OS X well

A G3 with less than a 100mhz system bus should never boot OS X no matter what amount of memory it has

[OverclockedHomoSapien]

Loco Bozo is right, the differences you saw between an iBook and iMac are probably due primarily to the differences in HD speed. Laptop HDs are very slow compared to desktop HDs. I might be wrong but I think the new iMac has a 7200 rpm HD, while the iBook has a 4200 rpm HD. The titanium has 5400 rpm HDs, at least in the high end model, to give you an idea of the range of HD speeds available.

Although SOME of the speed difference was undoubtedly due to the G3 processor. Apple optimized lots of OS X's code for altivec, and a G4 does run OS X better than a G3. For example, OS X runs considerably faster on my Powermac G4 400 MHz compared to a 500 MHz G3 iMac. But once again, there is the issue of HD speeds; my powermac has two 7200 rpm HDs, while the iMac I compared it to has a 5400 rpm HD.

One way to compensate for a slow HD is to load the computer up with as much RAM as possible. OS X relies heavily on virtual memory when there is low system RAM, but over 500 MB RAM or so pageouts begin to drop and system performance increases. And the slower the HD, the greater the boost in system performance from added RAM.

I'd suggest loading that iBook up with as much RAM as you can afford, at least 500 MB or so. This won't speed up application launch times (since the app must be read from the HD into RAM or VM), but it will speed up overall system performance.

It would be very interesting so compare the speed of OS X on a Powermac with two HDs, one 5400 and one 7200, with an OS X install on each HD. That would settle once and for all how much of a difference HD speed makes.