Kingston Predator 16GB (2x8GB) 1866 MHz DDR3 RAM/Memory Kit Review (KHX18C9T2K2/16X) - Test Setup & Overclocking
CPU: Intel i5-3570K
CPU Cooling: Cooler Master TPC 812
Motherboard: Gigabyte Z77X-UD3H
OS HDD: OCZ Agility 3 120GB SSD
Secondary HDD: Kingston HyperX 3K 240GB SSD
OS: Windows 7 Professional 64-Bit
We took several approaches to overclocking the Kingston HyperX Predator kit. Since overclocking can be accmoplished by lowering timings and/or clock speed, it can be a tricky business to find the perfect clock so there's no simple formula. Think of it as a race, where one racer is twice as fast as the other. The slower one gets to go first (lower latency, less wait time) but runs less fast. The faster runner (higher clock speed), has to wait a little bit longer to start running (higher latency) but catches up and passes with greater speed (higher clock). Now lets, for simplicity's sake, assume they arrive at the hypothetical finish line at the same time, both racers have the same relative speed. So with this analogy we can see that overall RAM speed isn't remarkably simple, and is a "tango" between clock speed and latency. Generally speaking, the faster runner will finish first, but often to increase that speed, he must take longer "rests," which somewhat offsets his gains. This is what we see by the diminishing return in memory overclocking by increasing the clock speed.
First, we wanted to see how low the timings could be set at the Profile 1 XMP setting, which runs at 1866 MHz and 9-11-9-27 timings . I was a little surprised to see little flexibility for lowering the timings lower than the rated spec without failed POSTs and BSOD immediately upon boot, even as high as 1.65-1.70V. The rated timings (9-11-9-27) seemed to be about as low as they would go at the XMP 1866 MHz setting. Next, we tried for the best overall OC combination of timings and increase in clock speed. The kit seemed a bit more sensitive to timing reduction, which I wasn't surprised about from out failed attempts to lower the Profile 1 XMP timings. We were able to achieve the next step up at 2133 Mhz and had to drop the timings to CL11, at 11-11-11-32. This is pretty good for breaching the 2000 MHz mark and making it stably at 1.65V all to way to 2133 Mhz, so we're very happy with that result.
Originally I planned to compare these benchmark results against those from Patriot's Intel Extreme Memory kit, but the numbers were virtually identical. Since there was no statistically significant difference, I decided to stick with just analyzing how these modules performed under different clock conditions and it's maximum clock speed.