2-2-2-5!
Corsair markets the XLPRO line in packages of 512MB and 1GB, thereby making modules either 256MB or 512MB in size. Corsair tests them as a pair and packages them under the TwinX name, suggesting that they're especially suited to be run in motherboards that support dual memory channels. Non-TwinX Corsair modules, however, seem perfectly happy in DC mode.
Here is where the PRO nomenclature comes in. Corsair uses oversized heatsinks as first seen in its XMS4000PRO line. Larger aluminium heatspreaders should, ceteris paribus, afford greater heat dissipation and diffuse localised heat build-up. These 'spreaders are 95% larger than the ones found on regular XMS modules.
Flipping one of the modules on its side shows the same LEDs as found on the XMS4000PRO pair. The 18 LEDs per pair highlight RAM accesses. We reckon it's a token measure to wow the enthusiast who also likes good-looking components. Obviously, a windowed case is a necessity, otherwise you're missing the entire point.
And there you have it. The lowest latency DDR400 memory that's currently available. 2-2-2-5 timings will guarantee excellent default performance.
Prising off one heatspreader isn't recommended. The 'spreader's attached to the double-sided RAM modules by glue that's evenly spread. Note the 9 LEDs at the very top?. We also want to see how Corsair has managed to engineer and qualify such low latencies. Is it the return of Winbond's legendary BH-5s or has Corsair had to go further afield. The answer is on the following page...