I see screen tearing pretty often while scrolling webpages up and down, and it has been like this from day 1. But now I purchased an external monitor which is huge (23 inches compared to the Mac's 11), and the effect is more visible. It is driving me nuts and giving me headaches.

I wonder if you see the same. I was reading a lot about this problem, and it seems to be present on MacBook Pros as well? Can someone confirm I'm not alone?

In other words: I'm deciding weather to go through warranty repair, or if it makes no sense if all of theme exhibit same behavior.

It is shame to see this beautiful machine with an insane price tag to be lagging when browsing web, when the processor is just sitting there idle at 4-12%!

This is an example I found on Wikipedia that more or less describes what happens when I scroll up down. The effect is not so pronounced and clears when I stop scrolling, but it is sure annoying the hell out of me.

Firefox is tearing like hell, Chrome less, Safari exhibits jagged scrolling but less tearing compared to Chrome and Firefox.

With synthetic benchmarks I don't see any problems with hardware. But this is not particularly revealing.