When we last took a look at some DDR2 memory back in October of 2004, the technology was still a bit new and didn't seem to offer any tangible performance benefits over standard DDR RAM. Higher speeds could be obtained with DDR2 though, and these modules required less voltage, thus lowering overall power consumption. The caveat with DDR2, however, was that early sets were much higher priced per MB than older DDR memory, and latencies were generally much higher, which kept performance on par if not slightly off the existing model. The Intel camp was left without any options, as the 925 series of chipsets and now the newer 945/955 motherboards only support DDR2.
As anybody familiar with PC hardware knows, give manufacturers some time, and they will improve on their products exponentially. Over time, latencies and prices have both dropped, which has made DDR2 very attractive for new system builders. But, memory speed remained mostly as a constant at 533MHz. So, what else was there to do, but raise the speed to increase bandwidth even further. Higher speeds can come with a price however, as the memory ICs might not be able to handle lower latencies at higher speeds. To find out which is more valuable, tighter timings or higher speeds, we turned to two of the bigger memory resellers and took some of their latest offerings to task in the HotHardware labs. Up for battle are Corsair's TWIN2XA1024-5400UL and Kingston's KHX6000D2K2/1G memory kits. It's a bit of a rematch from our original review, although much has changed internally.
Both kits are rated for operation at 675MHz with SPD settings of 4-4-4-12. Corsair has placed the label 'UL' on this new set, short for Ultra-Low Latency, and they may be the first DDR2 modules we have seen that are expected to run stable at 3-2-2-4. Kingston, on the other hand, have upped the speed ante, as the "6000" in the product name stands for PC6000, or DDR750. New motherboards, such as those based on the i955X have new dividers in the BIOS that allow for these higher memory speeds. Let's get to testing and see which set comes out on top.