Since our last DDR-2 memory review back in March of this year, the market has change in positive ways for enthusiasts who are on the Intel side of the fence - we have quicker RAM and new platforms which allow for flexible overclocking, such as nVidia's nForce4 Intel Edition chipset (C19).
The C19 chipset from nVidia brings a new meaning to memory overclocking with unprecedented overclocking support through a real special memory controller. In older chipsets (such as Intel's 925X and 925XE and in fact all older chipsets) there was limited memory divider (or ratio) options built into the memory controllers. The dividers determine memory clock speed based on the CPU FSB - for instance, if you wanted to overclock your memory above 420MHz (say 315 FSB with a 3:4 ratio using a 266MHz FSB EE), you would have needed a very overclockable CPU or spend a lot of money on extreme cooling methods which isn't for everyone.
The new C19 chipset is somewhat unlinked and unattached (or asynchronous) between CPU and memory meaning you can adjust the memory semi-independent of the CPU FSB which is definitely a big bonus for Pentium 4 overclockers and just might help pull some enthusiasts from AMD to Intel. Both clocks are still linked deep down in core logic, however nVidia has added a lot of divider options (and we mean a lot!) which allows the user to manually enter a clock speed for their RAM... without having to worry if their CPU can keep pace - flexibility at it's best. Keep in mind changing the CPU FSB will alter memory clock speeds but only up to around 25MHz DDR, which isn't a huge deal. Of course, this setup works both ways...if the user wants to overclock their CPU and doesn't have the memory which can handle the high FSB, no dramas here either. This type of overclocker's nightmare is a thing of the past on nVidia's latest marvel of a chipset and makes testing memory a joy for us.
In our DDR-2 roundup in March we compared several different low latency DDR-2 675MHz memory modules and were happy with our results. Since then companies like Corsair haven't stop working and are pushing even lower latency memory for the Pentium 4 platform and modules which can be overclocked to some pretty serious levels, which is just perfect now we have platforms like C19 to work and play with.
While low latency memory for Intel processors isn't anywhere near as critical as it is for AMD processors, tight timings or lower access latency do help boost performance without question. More critical on the Pentium side is bandwidth - and as much as possible. In an article from April this year entitled "DDR-2 Memory Investigation Guide - Making sense of memory settings" we discovered through extensive testing that higher bandwidth rules over low latency for Pentium 4 - at least on the older Intel chipset we tested with at the time of publishing.
Earlier this year Corsair, a memory maker who specializes in enthusiast RAM, launched their 5400UL part which is designed to offer impressive timings (3-3-2-8) at 675MHz DDR and is in fact designed for the C19 chipset but will work on other DDR-2 based systems. Not only that but they make claims that their memory can do over 800MHz DDR with relaxed timings. With our fresh new C19 motherboard, we'll take Corsair's latest performance DDR-2 memory for a spin and see how it performs at stock speeds and just how far we can overclock the sticks. We hope to find out just how Corsair's memory performs against older DDR-2 memory and what type of impact on performance we find by running DDR-2 memory at 850MHz DDR with relaxed timings compared to around 730MHz DDR with tight timings on the latest Intel platform from nVidia.