SBM 3: High-End System

Memory: 2x 1 GB Crucial Ballistix PC2-6400

Last time we used Crucial's Ballistix PC2-8000, a part that we logically thought should have been rated at PC2-8500 speed instead since 1066 MHz data rate (PC2-8500) is a standard ratio for FSB1066 processors on several chipsets. Crucial dropped its Ballistix PC2-8000 (DDR2-1000) model almost immediately following our previous article and replaced it with a PC2-8500 version, but we suspect the new version uses the same subcomponents.

Most performance builders will use a DRAM clock ratio of 1.5 times the processor's FSB clock, formerly resulting in a DDR2-800 memory speed (400 MHz clock) being paired with Intel's FSB1066 bus (266 MHz clock). That same ratio would have made Intel's latest FSB1333 (333 MHz clock) a perfect match for PC2-8000 (500 MHz clock), but those modules were retired before the new FSB was released.

With a few hundred dollars to buy any memory we wanted - short of Corsair's insanely-expensive DDR2-1111 CAS4 - we could have easily chosen the newer Ballistix PC2-8500 and ran it at a 1000 MHz data rate rather than its rated 1066 data rate. Why didn't we? Our February mid-price RAM comparison proved that the far-cheaper Ballistix DDR2-800 had similar capabilities, including the ability to clock beyond data rates of 1200 MHz!

In fact, our Ballistix DDR2-800 features the same EPP value set previously found in Ballistix PC2-8000, with both models supporting 800 and 1000 MHz data rates at CAS 4 and CAS 5, respectively. Ballistix PC2-8000 is still available, but it's being sold under the PC2-6400 label.

Knowing all this, why would we buy the more expensive version? Crucial Ballistix Part Number BL2KIT12864AA804 costs around $110 at a variety of sources, with available rebates lowering its final price to as little as $70.

Thomas Soderstrom
Thomas Soderstrom is a Senior Staff Editor at Tom's Hardware US. He tests and reviews cases, cooling, memory and motherboards.