A leading manufacturer of overclocker-friendly memory modules, Corsair offered us one of its top products, a pair of modules intended to be clocked at 1067MHz. Corsair has reached that speed ahead of all its competitors and TWIN2X2048-8500C5 is the only two-module memory kit in this review to be rated for a frequency above 1GHz.
The Corsair TWIN2X2048-8500C5 kit consists of two 1GB DDR2 SDRAM modules that are each marked as CM2X1024-8500C5. According to the manufacturer, the default operating mode for that kit is a frequency of 1067MHz with 5-5-5-12 timings. The default voltage is 2.2V.
Corsair TWIN2X2048-8500C5 modules are based on Micron's chips which are widely used by many manufacturers to produce overclocker-targeted DDR2 SDRAM. Such chips can overclock well after a voltage increase, which is confirmed by the fact that they can be overclocked above 1GHz by setting their voltage 20-25% above the value written in JEDEC's specifications.
To cool the overclocked modules, Corsair uses its traditional black-anodized aluminum heat-spreaders on both sides of each module. The manufacturer's logo is painted in white on the heat-spreaders, and the sticker tells you the part number as well as speed, timings and capacity of the product.
Corsair TWIN2X2048-8500C5 modules feature the so-called Enhanced Performance Profile (EPP) which was invented by Nvidia's engineering and marketing folks to extend the SPD information. The Profile contains more information about the memory module settings to be used in overclocked modes. So, you shouldn't be surprised at the impressive contents of the SPD chip:
As you can see, the Corsair TWIN2X2048-8500C5's SPD contains “safe” modes (DDR2-533 with 4-4-4-13 timings and DDR2-800 with 5-5-5-18 timings) that allow starting the mainboard up without any problems. To overclock and run the modules in their “default” mode you need to specify some settings in the BIOS Setup. It is to simplify this process that the EPP contains two overclocking profiles that allow to easily switch this memory into DDR2-800 mode with 4-4-4-12 timings or into DDR2-1066 mode with 5-5-5-15 timings. The EPP is currently supported only by Nvidia's 500 series chipsets, so you can't use the EPP info on Core 2 Duo platforms - you have to manually configure the memory subsystem through the BIOS Setup.
The test results of the Corsair TWIN2X2048-8500C5 kit are shown below:
As you can see, this memory kit can work at frequencies up to 1128MHz. At a frequency of 1GHz it allows using 4-4-4-12 timings.