In this review, we benchmarked the Patriot PC3-15000 DDR3-1866 (PDC32G1866LLK) dual channel 2GB (2x1GB) kit. As mentioned before, these modules operate with a stock SPD timings of 7-7-7-20 at 1066MHz. In order to run them at its 1866MHz rated speeds, we require overclocking our testbed. As the Intel P35 and X38 chipsets are the only chipsets at the moment to support DDR3, our platform of choice for this review is the ASUS P5E3 Deluxe motherboard, running on the Intel Core 2 Extreme QX6850 processor. At stock settings, the QX6850 runs with a 333MHz FSB and 9x multiplier.
Now here comes a little math. Unlike the NVIDIA nForce series of boards with their pseudo-independent clocks, there is no proper ratio to run at DDR3-1866 on current Intel chipsets. In order to get the Patriot DDR3-1866 to run at 1866MHz, ideally, one would have to overclock the FSB to 466.5MHz. Now, the ASUS P5E3 Deluxe doesn't feature 0.5MHz FSB increments, so the closest FSB to achieve 1866MHz DDR3 memory is 466MHz, which is 1864MHz. During our testing however, we could not get the Patriot DDR3-1866 to run at this speed. Even after pushing the memory voltage up to 2.1V and further relaxing the memory timing to 9-9-9-25 (the Patriot DDR3-1866 is rated to be able to run at 1.9V and 8-8-8-20), we were unable to achieve a stable environment. So, we worked backwards with the FSB to find the most stable sweet spot, and stopped at 460MHz FSB using a 2.0V memory voltage and sticking with the 8-8-8-20 timings. This translates to a DDR3 frequency of 1840MHz, 26MHz less than its rated operation timing.
Also note that because of the high FSB overclocking, the resulting CPU speeds would have been altered as well. At 460MHz, we had a choice of running the QX6850 at 2.76GHz (460x6) or 3.22GHz (460x7). There is no middle ground here and running the processor lower will degrade overall performance, which defeats the purpose of overclocking in the first place. However, running at 3.22GHz means you must take into consideration the higher CPU speed as well, which will affect overall performance instead of just the faster memory speed. There is really no way around this since there is no proper way of running DDR3 at 1866MHz with a 333MHz FSB strap.
To compare, we will also run the Patriot DDR3-1866 memory at DDR3-1333, 7-7-7-20 speeds to match the Kingston HyperX DDR3-1333 module used as the reference performance benchmark in this review. This will at least form a baseline on how the Patriot DDR3-1866 memory compares to the Kingston HyperX DDR3-1333 in a level ground.
Math aside, the following hardware configuration shows the full test bed setup we will be using for this review:-
The following benchmarks will be used in this article to gauge the performance of the Patriot DDR3-1866 memory:-