Introduction

Currently, the high-end memory market is splintered between DDR2 and DDR3, with Intel supporting both, while AMD is sticking with DDR2 until its next generation. The primary Intel DDR3 platforms feature the X38 and X48 Express chipsets, with default support to DDR3-1600, and unofficial support going much higher. DDR3-1600 is the current "sweet spot" for enthusiast DDR3, with special attention paid to low-latency modules in the CL7 range. Because of its design, DDR3 memory is very susceptible to latency issues, and achieving lower timings can be more beneficial than simply raising clock speeds.

The Corsair XMS3 PC3-12800 2x1GB (TWIN3X2048-1600C7DHXIN) Kit

Corsair offers several different DDR3-1600 memory kits, including both CL7 and CL9 memory timings, with some offering support for Intel (XMP) and NVIDIA (EPP 2.0) overclocking profiles. The Corsair TWIN3X2048-1600C7DHXIN is one of the higher-end configurations, and includes 2x1GB of XMS3 DDR3-1600 modules, rated at 1600 MHz with CL7 timings and using a 1.8V or higher memory voltage.

By default, these Corsair XMS modules operate at DDR3-1333 speeds, using CL9 timings and a 1.6V memory voltage, but are certified for 1600 MHz operation at CL7 timings. The "IN" at the end of the product name translates into Intel Extreme Memory Profile support with X38 and X48 motherboards. This feature automatically loads a profile through the BIOS, which when selected, will enable the stated 7-7-7-20 timings at 1.8V, as well as any other custom settings. End users can do it manually, but the XMP support simply makes the process easier and more seamless.

The two XMS3 modules feature a silver exterior, using the Corsair DHX (Dual-Path Heat Xchange) system, with extruded aluminum heatsinks and fins, for maximum DDR3 module cooling. The only negative with this design is that the modules are slightly taller than standard, and can be a bit more difficult to install in tight case environments. Corsair also offers a full lifetime warranty on this DDR3-1600 kit.

Overclock Testing

Since our Corsair XMS3 PC3-12800 2x1GB kit offers Intel Extreme Memory Profiles, our first step was to test the CL7 1600 MHz profile. The Crucial XMS3 boots at DDR3-1333 CL9 by default, to allow full compatibility, and it's up to the user to do any further tweaking. The Intel Extreme profile shows up automatically in the System BIOS, and once enabled, the CL7 memory timings, 1600 MHz speeds and 1.8-1.9V memory voltage setting are automatically enabled. This profile booted without issue, and we completed several lengthy test runs without issue.

Moving up to higher DDR3 clock speeds, while maintaining the low CL7 timings, was difficult, and we were unable to reach a DDR3-1800 clock at CL7 timings - even at 1.9V. To test the kit's true overclocking limits, we relaxed the timings to default CL9 levels. By using a 1.8V voltage, we were able to hit DDR3-1800 speeds, and on a more fully-featured Gigabyte X48 board, we hit DDR3-1900. We couldn't quite reach a 2000 MHz clock, but it was very close, and 1900 MHz still gave us all the overclocking headroom we'd need at CL9.