Corsair currently produces both overclocking-related memory sticks and value/mainstream ones. Although they have two separate lines, each one with its specifications and its price tag, Corsair generally manages to somehow introduce a lot of concepts and technology from its overclock-based XMS2 line to the value line.
And as a result, most of its DDR/DDR2-based products have good overclocking potential. That's exactly the case with the QUAD2X4096-6400C5DHX line, which was initially targeted at the high end segment, at least when we're speaking about total capacity. And while at first that may seem perfectly normal, especially to 64-bit OS users, a quick search will reveal that actually few memory integrators offer 4 memory sticks setups.
DHX stands for “Dual-Path Heat Xchange”, this type of radiator being used mainly in Corsair's high-performance memory modules. Because of this important addition, the DDR2 chips are able to sustain a very high load without overheating. And of course, they will overclock very well, just as any other DHX-cooled memory. Corsair claims that they have pre-tested this model at stock 1.8V and it showed no abnormal behavior. They also state that with the help of that voltage, the sticks can run in a 3-4-3-9 setup without losing stability even at 800MHz-DDR speed.
The timings can indeed be pretty tight, but don't expect to run such a setup on every motherboard you come across. Only certain types of motherboards can deliver the right amount of voltage in order to produce a tight setup. Moreover, you will also require a highly tuned BIOS in order to tighten all timings not only the CAS/Trcd setup.
Price-wise, a 4GB kit composed of 4 x 1GB sticks can be yours for less than $500, which is not that bad if you want low latencies at a reasonable speed. Actually, it's also a good offer, considering what is the price tag on 2x2GBs of high performance G.Skills or Patriots.