Corsair XMS2 PC2-8500

Corsair needs no introduction in the enthusiast community. They’ve been making high-end modules since 1994 and are considered by many to be one of the best in the industry. Corsair’s mainstream XMS series modules have been around for some time and more recently, their DDR2 based XMS2 series. Today we’ll be taking a look at the Corsair TWIN2X2048-8500C5 kit.

Specifications (taken from the Corsair XMS2 product page)

• Part Number: TWIN2X2048-8500C5
• Capacity: 2GB kit (1GBx2)
• Type: DDR2 240-pin DIMM, Unbuffered, NON-ECC
• Rated Frequency: DDR2 PC2-8500 (1066MHz)
• Rated Timings: 5-5-5-15
• Rated vDIMM: 2.1V
• Warranty:Lifetime
• Approximate Retail Price: $84.99USD with MIRs that can take it as low as $69.99USD.

The TWIN2X2048-8500C5 kit comes packaged in a simple blister pack. Inside you’ll find some basic installation instructions. The specifications are listed on the modules themselves.

I’ve always liked the simple appearance of the XMS series heat spreaders. I’m not a big fan of green PCB, but if it means a savings of a few dollars, that is usually more important to most people.

All the pertinent specifications can be found on the modules themselves. The kit we’re looking at today is version 3.1 of the CM2X1024-8500C5 kit. There are several revisions of this kit around today, so please be cognizant of which revision we are reviewing, especially when looking at overclocking results.

I was pleased to see that the XMS2 heatspreaders were making good contact with the ICs. Interestingly, the DIMMs appear to be single sided with only eight ICs per DIMM. Most 1024MB DIMMs employ 16×64MB ICs. The other side of the module seems to have a second piece of PCB adhered to fill any gap in the heatspreader.

I had no issues getting this kit up and running. Setting vDIMM and the correct frequency in the BIOS was all that was necessary.

Overclocking and Frequency Scaling

I put the XMS2 PC2-8500 kit through its paces on our Intel 775 test rig outlined in the ‘Testing Methodology’ section.

WARNING: Increasing memory voltage beyond manufacturer specifications can be harmful to the modules and other system components. Although we subject modules to high levels of vDIMM for testing purposes, many of these results are not suitable for 24/7 use. Always consult with your memory manufacturer to see what a maximum ’safe’ voltage is for 24/7 use. Increase memory voltage at your own risk!

While maintaining 5-5-5 timings, I was able to obtain an impressive 1180MHz for an overclock of about 114MHz. Increasing the vDIMM did not improve the stability of the modules, and 2.55V increased the number of Memtest86+ errors. Definitely not Micron D9 ICs based on their vDIMM response, but they definitely have some headroom to spare.

Most PC2-8500 kits can run at 800MHz with 4-4-4 timings. The XMS2 kit does not disappoint in this regard. We are able to get to about 915MHz before they top out. Again, vDIMM increases did not benefit these modules.

With super-tight 3-3-3-8 timings, there was no issues getting them running at 667MHz. In my expeirence, most PC2-8500 kits will be able to run at pc2-5300 frequencies at these very tight timings. The XMS2 kit topped out at about 713MHz. Interestingly, some extra vDIMM did benefit them slightly when the timings are tightned up this much.