Corsair XMS2 DHX PC2-6400 4GB Kit Page: 1
Corsair XMS2 DHX PC2-6400With the current pace of hardware development it is all too easy to let the mainstream, affordable tech fall by the wayside. The DDR2 module is still the mainstay of the enthusiast memory market and has recently been overshadowed by DDR3. Today, however, we are taking a look at a 4GB kit of Corsair XMS2 PC2-6400 sporting the patented DHX heat spreader technology.
Up until recently, with the launch of memory hungry Windows Vista, quantities of memory in the range of 4GB and above would have been deemed excessive in a desktop computer - regardless of how many demanding games you could throw at it. In past months however, with the release of several ground breaking games and increasing popularity of Vista 64-bit, 4GB has become somewhat of a necessity for the hardcore gamer.
The specifications for the memory modules we are looking at today are as follows:
Sporting Corsair’s signature fin memory heat sink and patented heat-removing printed circuit board design, the new XMS2 DHX products feature mainstream performance while promoting increased stability. DHX technology allows this memory to have superior thermal characteristics to enable it to run cooler than a module with stamped or mesh heat spreaders. The result is enabled superior reliability, stability and performance capability.. It has been tested extensively in multiple DDR2 motherboards to ensure compatibility and performance at its rated speed.
Part Number: TWIN2X4096-6400C4DHX
Speed:  PC2-6400 (800mhz)
Size: 4GB (2 x 2GB)
Latency: 4-4-4-12
Pins: 240
So on the face of things, there is nothing revolutionary about what the memory is offering. The patented DHX technology however certainly has promise, the system aims to provide a direct metal to metal contact between the inner plates of the heat sink and the tracks on the modules PCB. Studies carried out show substantial amounts of the heat generated by IC's is still conducted into the PCB, meaning the DHX system is currently the only solution on the market to this problem. Hopefully this technology will stand the memory in good stead when it comes to pushing up the Mhz.
As with all of Corsairs RAM, the XMS2 DHX kit is covered by an extremely reassuring life time warranty providing the memory was purchased through Corsair or one of their many authorized retailers. Further details on Corsairs warranty policy can be viewed here.

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Packaging & Appearance
Memory modules are not often treated to nice lavish packaging. The usual solution is to encase the product in a vacuum molded, plastic blister pack. While this offers buyers a good look at what their money is actually buying and allows the more eye catching modules out there to stand out were they stocked on a shelf, it does not offer a great deal of protection for the contents. Admittedly, however, the aluminium heat spreaders seen on all mid to high performance kits will add considerable durability in the hands of clumsy couriers.
The XMS2 DHX follows the current trend in this department and is distributed in the normal plastic packaging. The front of the packaging is fairly distraction free, sporting the XMS colours and memory quantity, generally giving the modules center stage. The back side of the packaging has some basic information about the modules and their DHX heat spreaders, a cut-away diagram of the memory, details of Corsairs optional AirFlow DIMM cooling system (designed to accomodate the DHX modules additional height) and of course the usual contact details.
Packaging Front Packaging Back
One thing you will notice the packaging is void of is any specifications apart from the size. I can only guess this is to allow the use of the same packaging inserts across the whole XMS2 DHX range. For proof of the contents one will have to refer to the price check sticker on the back of the packet, which carries the modules full part number, which contains the memory rating and overall size of the kit.  While this is not really a problem for those buying from online retailers and those who know what they're looking for, it could possibly lead to some confusion off the shelf or pre / post shipping. On the whole though there are certainly no product specific shortfalls to report.
Modules Front  Modules Back
Module Labels  Module End
Visually the kit is definitely not the every day set of ram. The huge ridged heat spreaders, adorned with four rows of heat dispersing blades, encase extra large black PCBs. The XMS2 stickers adding an eye catching streak of colour. In the fourth picture above you get a look at the point of this additional height and elaborate heatsink.
The extra few millimeters of PCB are plated with a thin layer of metal which looks to be the same coating used on the pins. This is then in turn connected to the center two rows of the heatsink, allowing for dispersion of not only IC generated heat but also the heat in the PCB.
Heatsink Top view   Heatsink End View 
Usually at this point we would remove the heat spreaders from the modules to take at look at the choice of IC's in use. Due to the construction of the heat spreaders however, removal would have been abnormally risky and particularly difficult. For those who are interested, we have done the research for you and can tell you this revision of the modules uses chips produced by Powerchip Semiconductor Corp. Another thing worth mentioning is the double sided distribution of the ICs, this works in favour of the kit, allowing greater utilization of the heatsink.

Corsair XMS2 DHX PC2-6400 4GB Kit Page: 3
Test Setup
To ensure that all reviews on Overclock3D are fair, consistent and unbiased, a standard set of hardware and software is used whenever possible during the comparative testing of two or more products. The configuration used in this review can be seen below:
Intel Core 2 Quad Q6600 "G0" 2.4GHz 2x 4MB
• Asus Rampage Formula X48 DDR2
• OCZ Vendetta 2 + Stock Fan

Corsair XMS2 DHX PC2-6400 4GB Kit (4-4-4-12)
OCZ Platinum 4GB Kit (5-4-4-15)

Graphics Card
• Sapphire Ultimate X1950 Pro 256mb PCI-E

Hard Disk
• Hitachi Deskstar 80GB 7K80 SATA2 7200RPM 8mb

Operating System
• Microsoft Windows Vista Ultimate (Latest Updates)
To allow for a broad range of reliable results, the following benchmarking tests were used:
 Synthetic Memory Subsystem
• Sisoft Sandra XII 2008c
• Lavalys Everest 4.0

File Compression & Encoding
• 7-Zip File Compression
• River Past ViMark

3D / Rendering Benchmarks
• Cinebench 10
• 3DMark05
• 3DMark06

3D Games
• Quake 4
• Bioshock
• F.E.A.R
Settings & Overclocking
As with all memory reviews on Overclock3D the XMS2 DHX modules were subjected to a series of benchmark tests under several different configurations. The configurations used tested the memory's ability to run at high frequencies with stock timings, high frequencies with loosened timings and also ensured that that the modules could run with 100% stability at their advertised speed, latency and voltage settings.

Highest Frequencies & Stock Timings
DDR2 883 / 4-4-4-12 / 2.3v

 cpuz screenshot  cpuz screenshot
With the timings kept at the fairly low stock settings of 4-4-4-12 and the voltage upped to 2.3v, the XMS2 DHX kit managed to achieve a healthy overclock of 42 Mhz (DDR2 83) which took the overall bus speed to DDR2-883
 Highest Frequencies & Relaxed Timings
DDR2 1149 / 5-5-5-12 / 2.3v
cpuz screenshot  cpuz screenshot
With the timings loosened a little to 5-5-5-12 and the voltage kept at 2.3v, the XMS2 DHX managed an impressive overclock of 174 Mhz (DDR2 349), bringing the kit to a fantastic DDR2 speed of 1149. All the results taken were tested for absolute stability with OCCT stress testing.
Maximum Overclock
For the purpose of comparison, the XMS2 DHX kits results in all the testing carried out, will be displayed alongside those of the similar OCZ Platinum Kit. Both 4GB kits cost around the same price and carry the same native speed ratings.
The first comparison we can draw is between the two overclocks obtained with these kits:
Overclock Results

Corsair XMS2 DHX PC2-6400 4GB Kit Page: 4
Sisoft Sandra is a synthetic benchmark utility capable of reporting and benchmarking a wide range of system components. As the focus of this review is around the performance of the Memory subsystem (rather than overall system performance), only the Memory Bandwidth and Memory Latency benchmarks are utilised.
SiSoft Bandwidth Results
SiSoft Bandwidth Results 
SiSoft Latency Results 

Everest is in many ways similar to Sisoft Sandra. Focusing mainly on Software and Hardware information reporting, Everest also comes with a benchmark utility suitable for testing the read, write and latency performance of the memory subsystem.
Everest Read Results
Everest Read Results
Everest Latency Results

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ViMark is the latest addition to the OC3D testing process and a relatively new benchmarking application in general. Designed to take the inaccuracies and guesswork out of measuring the time taken to encode video files, ViMark produces easily comparable and consistent results for encoding Windows Media, Quicktime, AVI and Gif files.
ViMark Windows Media Results
ViMark Apple Quicktime Results
ViMark AVI Results
ViMark GIF Results
7-Zip is an open source winzip-style file compression utility that has the ability to compress and decompress many file formats including it's own .7z compression scheme. 7-Zip also comes complete with its own benchmarking utility for gauging the compression and decompression speed of the system that it is installed on.
7Zip Compression Results
7Zip Decompression Results

Corsair XMS2 DHX PC2-6400 4GB Kit Page: 6
Cinebench 10 is a benchmarking tool based on the powerful 3D software Cinema 4D. Consequently, the results of tests conducted using Cinebench carry significant weight when analysing a computer’s performance in everyday use.
Cinebench Rendering Results
Cinebench Rendering Results
Cinebench OpenGL Results
3DMark is a popular synthetic gaming benchmark used by many gamers and overclockers to gauge the performance of their PC's. All 3DMark runs were performed using the default configurations and with AA / AF disabled.
3D Mark 05 Results
3D Mark 06 Results

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Quake 4 is a game built on the Doom 3 engine. Benchmarking was performed using Quake4Bench and a custom timedemo recording along with 0xAA, 0xAF settings at a resolution of 1024x768.
Quake4 FPS Results
F.E.A.R. is a game based on the Lithtech Jupiter EX engine. It has volumetric lighting, soft shadows, parallax mapping and particle effects. Included in the game is a benchmark facility that taxes the entire PC system.
FEAR FPS Results
Bioshock is a recent FPS shooter by 2K games. Based on the UT3 engine it has a large amount of advanced DirectX techniques including excellent water rendering and superb lighting and smoke techniques.

Corsair XMS2 DHX PC2-6400 4GB Kit Page: 8
As I said at the start of this review, technology is moving forward at an eye watering pace. DDR3 memory solutions are slowly starting to saturate the enthusiast market and are getting faster and faster by the month. The XMS2 DHX kit with us today though has shown that this trend is not becoming refined to DDR3, with the ability to reach speeds of DDR2 1149 with a minimal slackening of latencies this 4GB kit has outperformed a most of 2GB kits we have seen in both overclock percentage and overall speed.
While the looks of a memory kit do not in any way correspond with performance levels, it can sometimes contribute to the feel of quality. The huge heat spreaders, while giving the modules an intimidating look, feel very solid. Unlike the very papery feel of some cheaper heat dispersing solutions, the DHX kit feels like one well built piece. The bond between the spreader and the modules is steadfast, allowing for no movement whatsoever and the fins along the spine would take a fair degree of cack-handedness to damage.
While the results seen in gaming performance against the OCZ Platinum kit seem inconsistent with those obtained in benchmarking tests, this fractional but consistent difference can likely be attributed to the default sub-timings on each kit. Having been largely left to automatic during testing we can only speculate that the OCZ Platinum's sub-timings were slightly better suited to running these particular games.
Retailing at £69.99 with Komplett, the kit really does offer outstanding value for money for those still operating on DDR2 (the vast majority). At such a low price and high performance, the XMS2 DHX kit is more than the perfect accompaniment to a copy of Vista 64-bit or the latest resource hungry games.
OC3D Reccomended Retailer
The Good
- Massive overclocker
- Extremely affordable
- Good all round performance
- Innovative and well built heat spreader
- Striking looks and design
The Mediocre
- Usual flimsy blister pack
The Bad
 - Absolutely nothing
Overclock3D Editors Choice Award Value For Money Award
Thanks to Corsair for supplying the product for review.
As usual if you've any comments on the review, head on over to the Forums and tell us what you think.