[nJm]

Is there much of a performance difference between the 1.6 and 1.8 ghz iMacs? I already have an external dual layer DVD burner which I've been using on my iBook so the Superdrive isn't necessary. All I'll be using the iMac for is iPhoto/iTunes, Office and maybe a game like The Sims 2.

From what I gather the front side bus is a little slower? Has anyone actually noticed a difference? I'm thinking I should probably get the 1.6 and spend the left over money on a ram upgrade.

[iPoder]

Based on Macworld Magazine December edition,

iMac 1.8 Ghz has in average 5% performance edge over 1.6 Ghz. The test applications are Phtoshop, Cimema 4D, Compressor, iMovie, iTunes.

As expected, the frame rates of Unreal Tournament are the same on both machines due to the same GPU.

If you already have external DVD drive, I say that 1.6 Ghz is a better buy for you.

More details (from the magazine)

Speedmark 3.3 average: 150 (1.6) vs. 162 (1.8)
Photoshop 8.0: 2:02 (1.6) vs 1:51 (1.8)
Cinema 4D XL 8.5 Render: 3:24 (1.6) vs. 3:02 (1.8)
Compressor MPEG2 Encoding: 11:17 (1.6) vs. 10:00 (1.8)
iMovie 4.0.1 Render: 0:42 (1.6) vs. 0:40 (1.8)
iTunes 4.6 MP3 Encoding: 2:06 (1.6) vs. 1:52 (1.8)
Unreal Tournament avg. framerate: 33.5 (1.6) vs. 33.6 (1.8)

[macaddict0001]

1.6 and a ram upgrade is a better deal.

[the_glassman]

The 1.6 is a pretty good deal if you already have an external drive you would rather use. Another advantage you have is, the external drive is faster and you can make one to one copies.

[iDaver]

I'm thinking the 1.6 might run a little cooler so the fans might not run as much. A 5% difference in speed is nothing.