IntroductionCorsair XMS4400 TwinX 1GByte Memory Review
Chipset engineers and system memory manufacturers have been playing a game of one-upmanship throughout 2003. Ever since we first laid eyes on Intel's Canterwood and Springdale chipsets back in April, we've realised that our previously held notions of Front-Side Bus ceilings had been wholly inaccurate. Intel decided to jump straight from a conventional 133MHz FSB (Granite Bay was the first sign of Intel readying a dual-channel chipset for the masses) to 200MHz. That had the knock-on effect of requiring suitable CPUs and memory. PC3200 was now strictly specification. AMD's move to the same 200MHZ FSB came soon after. The Barton XP3200+ has remained the fastest K7 AMD CPU throughout '03.
We're referring to Intel's efforts in more detail because its i865PE / i875P chipsets have shown a regular propensity to hit 250MHz FSB with ease. We've even seen the magical 300MHz barrier broken. This isn't just a controlled experiment with an engineering CPU. Rather, recent batches of 2.4, 2.6, and 2.8GHz Pentium 4 'Cs' have managed to hit 3.3 - 3.5GHz at default volts. Take 3.3Ghz with a multiplier-locked 2.4GHz M0-stepping CPU, for example. That results in a 275MHz FSB speed. Select motherboards can maintain decent stability at this elevated speed, presumably with locked buses and decent Northbridge cooling. The enthusiast is then left to rue the inability to run RAM synchronous the Northbridge's speed. Sure, most boards offer dividing ratios that will allow for slower memory to be used, but that's not a desirable state of affairs, especially when the effects of clock buffering begin to impact upon performance.
Basically, the informed enthusiast can buy a 2.4GHz Pentium 4 C processor that will most likely overclock to 3.3GHz (275MHz FSB) at default volts. The enthusiast has a wide choice of Springdale and Canterwood boards that may also hit that FSB speed. What's left is for system RAM to catch up. Corsair, it appears, has been fighting RAM's cause for the latter half of 2003. It's now in a position to place the performance onus back on motherboard manufacturers and to the quality of Intel's CPU yields. Our previous look was at its XMS4000 range, which tied in with a 250MHz FSB. Rather than inch up the frequencies like other manufacturers / distributors, Corsair has decided to go for the jugular with some all-new XMS4400 RAM. That translates to DDR550, or 275MHz in more common parlance.
The question now is not whether system RAM can keep up with the potential shown by motherboard chipsets and CPUs. It's now a case of ensuring you have a board and processor that can match the RAM's potential. It appears that XMS4400 TwinX memory is reserved for a system featuring the very best in overclocked components. Let's now see if we can make it purr at ultra-high speeds.