The dual-channel memory format is the standard for high-end performance systems, and is the de facto packaging for most DDR memory. The "matched pair" format has become very popular, as these DDR module kits are perfectly suited for the requirements of high-end dual-channel DDR operation, and are a much safer buy than purchasing one module now and hoping to match it up later. The most popular configurations are currently the 2x512-MB and 2x1-GB kits (although 2x2-GB are emerging) and with few exceptions, vendors offer the same basic speeds in matched pair DDR kits, as with their single module DDR.
The news got a lot worse in the dual channel DDR listings and the small price increases we found in the single module chart ramps up into high gear once we hit the matched pair kit level. The aggregate chart movement amounted to an increase of just over $100, and the price drops weren't exactly coming in waves. The only one that hit double digits was a $16 cut to the price of Mushkin eXtreme PC4000 2x1-GB. The higher priced DDR kits far outdistanced this, charting four double digit increases, including Corsair XMS PC4000 2x1-GB (+$20), OCZ PC4000 EL 2x1-GB (-$21), Kingston HyperX PC4000 2x1-GB (+$25), and Corsair XMS PC4400 2x512-MB (-$26).