Corsair XMS PC-4400 Memory

Introduction:

With the upcoming launch of DDR II motherboards it is safe to assume that DDR550 may be one of the last major speed grades available in DDR I from Corsair memory as they shift their attention to DDR II. While Corsair won’t confirm or deny that this will be the fastest DDR I module that they ship, they do admit it is a possibilty.

The TwinX1024-4400 is intended for use on motherboards based on the Intel 875P (Canterwood) chipset. The 1Gb memory kit that we are looking at today contains two 512mb matched memory modules. The latency is set by SPD to 3-4-4-8 which is loose, but is required due to the IC’s available that can reach these speeds.

Features:

The memory we are testing today are TWINX matched memory pairs that have been specifically designed for motherboards using chipsets with dual memory channels. All Corsair XMS4400 memory kits consists of two ultrahigh-speed memory modules that have been tested together at DDR550 (275MHz) on an ASUS Canterwood P4C800-E dual channel motherboard. Corsiar uses this ASUS board because it is one of the few that can reach speeds of 275MHz with stability (if all the right hardware is used). In all honesty the boards that can run DDR550 out of the box with no modifications can be counted on one hand, leaving this memory for the select few that have the right hardware and the need for speed. Since this memory is rated so fast and so few boards and processors can handle 275+ MHz FSB above this memory should be reserved for the extreme Intel enthusiasts who are wanting to run the highest possible memory speeds. To be able to run such amazing speeds these modules come with relaxed latency settings, but this is a key factor to allow extraordinarily high clock speeds for optimum performance in many system configurations.

The Corsair XMS4400 modules are designed to be run in overclocked systems and they do carry a full lifetime warranty. This means that Corsair products are guaranteed to operate, as specified by their datasheet and in the operating environment for which they were intended, for the life of the product.

As the label states Corsair’s XMS4400 memory is speed rated for 550MHZ (PC-4400) speeds at loose timings of CL 3-4-4-8, 1T.

What is under the heat spreader?

Once I removed the heat spreaders I found one of the newest Hynix IC’s on the market for high speed memory modules — Hynix D5’s. The full part number was found to be HY5DU56822CT-D5. If you want to sound like an uber hardware specialist these are known as Hynix Revision "C" IC’s in the D5 speed grade. For those of you who don’t know, these are the first IC’s from Hynix in the TSOP form factor that are rated above 400MHz. Actually, the D5 IC’s come rated at 500MHz, but with relaxed timings of 3-4-4. Corsiar takes batches of these IC’s and screens out the top performers that are found to be stable at 550MHz DDR for use on their PC-4400 memory line.

Decoding The IC:

For those of you that want to know the inside scoop on everything we broke down what the codes on the IC mean below. If you would like to do this on one of your personal modules or to double check us you can find the most current decoder right here on the Hynix site.

Hynix HY5DU56822CT-D5
Specification	Feature
HY	Hynix
5D	DDR I SDRAM
U	VDD=2.5V & VDDQ=2.5V
56	256M 8K Refresh
8	Organization = 8 x 32
2	4 Banks
2	Interface = SSTL_2
C	Revision Level #4
T	TSOP Package
D5	DDR500 3-4-4

Key Features:

• Memory amount: 2 x 512MB
• Access time: 4.0ns Hynix Rev "C" IC’s
• 550MHz (PC-4400) Unbuffered DDR Modules
• CAS latency: 3 clock cycles
• RAS precharge: 4 cycles
• RAS active to precharge: 8 cycles
• Command rate: 1T (1 cycle)
• Black heat spreader for thermal diffusion
• Latency: 3-4-4-8-1T
• 2.75V
• Lifetime Warranty

Now that we know what the memory is rated for by Corsair and what exact IC’s are being used on the Corsair XMS PC-4400 memory kit we can look at our testing to see how it really performs.