The only companies that make quad core desktops that are affordable and iBuyPower and Velocity Micro. Velocity Micro is barely affordable. But quad core chips are $299 for a 2.4 GHZ chip, so cheap.

Nobody really wants to fry eggs on their desktops at this time.

Basically quad core is struggling massively with 2 things

1. As the first line in my answers suggests – they are hot little bunnies! In a commercial dataroom this isn’t much of an issue as they tend to be air conditioned and super cool anyway – at home in your bedroom under a desk they become a neat way of making an insurance claim.

2. Home software just isn’t designed to take advantage of even dual core in a big way let alone quad. The applications and OS need to know HOW to get at the additional processing power otherwise there really is just no performance advantage.
We’ll see them in time – but to be perfectly frank I would rather run a dual board with dual GPU than spend the money on quad cores