Back in December, we reviewed one of the first DDR3-1866 rated memory modules around, a Patriot Extreme Performance PC3-15000 (PDC32G1866LLK). There was one caveat though, the Patriot Extreme Performance PC3-15000 was really just regular DDR3-1066 memory qualified to operate up to DDR3-1866. It was only meant for overclockers and enthusiast consumption. For the average consumer, the Patriot Extreme Performance PC3-15000 would only be detected as standard DDR3-1066 because it did not have any SPD settings for a higher speed grade.
Patriot has now released a new DDR3-1866 Extreme Performance kit, and this time, there's something for everyone. The new kit (PVS32G1866LLK) is packaged with Patriot's Viper Fin heat-spreader too, which looks more 'extreme' than the older mundane set. Patriot's specially designed Viper Fin is of a copper/aluminum composite. The inner copper layer is in contact with the chipset, while the outer finned area is made of aluminum for heat dissipation. Throughout the duration of our review, we've got to admit that the Patriot Viper Fin DDR3-1866 was the coolest memory we've worked with in a while - literally. It just could never get hot. Even under full load and over-volted up to 2.5V, the memory was only slightly warm to the touch. Zapping it with a laser thermometer yielded an outer temperature of 27 degrees (Celcius) and inner temperature of 30 degrees.
Physical features aside, the Patriot Viper Fin DDR3-1866 comes with Intel XMP support. This means that when used with an Intel motherboard that supports XMP memory (Intel X38, X48), it will automatically adjust your system parameters to achieve its optimal rated speed. Unlike the older PDC32G1866LLK set, the Viper Fin memory does not specifically require users to be overclockers in order to take advantage of its higher speed rating.
However, before we go on into performance testing, there is something to be said about XMP. While the Viper Fin supports this new profile setting, there are restrictions to its application. Firstly, you need to have an XMP capable motherboard. That's a given. Secondly, XMP is basically an extended profile setting - similar to NVIDIA's EPP memory - that overclocks the memory modules. There is no magic here, all the rules of overclocking, FSB, clock and divider ratios remain.
Most current Intel X38 and X48 motherboards have a maximum FSB:RAM ratio of 1:1. A 1333MHz FSB system should be able to run DDR3 at 1333MHz. To run DDR3-1600, you will need a 1600MHz system. Thus, using the same logic, you actually need a system capable of running at 1866MHz FSB (that's CPU and motherboard) in order to run DDR3-1866. When we reviewed the non-XMP Patriot DDR3-1866 memory, this issue was touched upon. XMP merely cuts through part of the hassle, by automatically setting up your system to run the RAM at 1866MHz. This includes overclocking your FSB to 1866MHz. You, the User, will still need to make sure that your CPU and other components can be scaled respectively to operate at these speeds.
XMP only guarantees your memory. Not your whole system.