Corsair XMS2 TWIN2X1024-4300C3PRO 1GB DC Kit

Written by John Chen    Saturday, 02 April 2005 11:00
Article Index
Corsair XMS2 TWIN2X1024-4300C3PRO 1GB DC Kit
Page 2
Page 3
Page 4
Page 5
Page 6
All Pages

Corsair's reputation grew rapidly when they started their XMS line of memory.  At that time, the inclusion of memory heatspreaders was a great addition to not only looks, but as a sign of high performance memory.  They moved on to make memory aesthetics even more impressive with the Pro series, which featured flashing lights that showed memory activity.  The latest innovation from Corsair was the Xpert series, which featured display LED's that show information about frequency, voltage, temperature, or even your own personal message.  It's no surprise why gamers like Corsair memory;  they just look so damn good.  What we have today is Corsair's new addition to their DDR2 line of memory.  Although not the fastest rated memory available, the XMS2 PC2-4300 Pro allows low latency operations at 266MHZ. 

DDR enthusiasts should be well aware that the PCB is a huge bottleneck when overclocking to high frequencies.  The perfect example would be the Brainpower 808.  Comparing our reviews of the Corsair PC4400C25 and the Corsair Xpert PC3200XL, both of which use Samsung TCCD chips, the PC4400C25 overclocks much better.  Of course there are other factors to consider, such as motherboard, voltage, and specific week of the memory IC's.  Yet, it's quite obvious that Corsair's custom designed PCB on their Xpert memory was hindering the overclock.  That can't be helped because their display LED's require a special PCB design.  Unlike DDR, DDR2 is still fairly new and has a lot of overclocking headroom.  After experiencing different DDR2 offerings from various companies, I can say that 99.9% of the time the motherboard and CPU are the major overclocking bottlenecks in an DDR2 system.  It's safe to say that the PCB certainly won't pose a threat here. 



Corsair XMS2 TWIN2X1024-4300C3PRO

The XMS2 PC2-4300 Pro features the Micron "fatty" chips.  Physically, these are the largest DDR2 chips available.  It's quite easy to recognize the chips, even though the heatspreaders weren't removed; a peek underneath shows the chips' large width.  Although the goals for use of DDR2 is low heat output and smaller form factor, the "fatty" chips still don't put out much heat.  The memory sticks were barely warm to the touch under hours of stress.  Currently, the Micron "fatty" chips are the only DDR2 IC's that allow true low latency operations.  Is Corsair's low latency rating of 3-3-3-8 considered low.  It's decent, but currently there are other manufacturers that rate even lower timings of 3-2-2, such as Centon, OCZ, and PDP.  Since Corsair uses the same "fatty" chips, I have no doubt that the timings can reach 3-2-2. 

The main attraction of the Corsair Pro series is the memory activity lights.  The lights flash depending on the amount of memory usage.  The shot below shows the memory running full load in Memtest.  The memory activity lights are great for cases with windows.  There is no software required for the lights to flash.  It happens all naturally and is already configured with the PCB.



Test System and Overclocking

Test System:

  • Intel Pentium 4 560 3.6GHZ
  • Abit Fatal1ty AA8XE
  • 2 x 512MB Corsair XMS2 PC2-4300 Pro
  • ATI Radeon X800 (400/490)
  • Enermax Noisetaker 470W

The proper method of testing DDR2 requires a CPU with low multiplier options.  Unfortunately Intel locks their CPU's, so the only processor that allows low multipliers would be their Extreme Editions.  Because the Extreme Edition processors are outrageously priced, I can't afford one for my testbed.  Thus the lowest multiplier available is 14x, from the Pentium 4 520 2.8GHZ processor.  The Pentium 4 560 3.6GHZ processor I'll be using today provides a range of multipliers from 14x-18x.  For testing, the 14x multiplier is used for all benchmarks and tests. 

The Abit Fatal1ty AA8XE is one of the best overclocking motherboards available.  It can reach extremely high FSB without any modifications.  The motherboard also allows high VDIMM options of up to 2.5v.  The stock voltage of DDR2 modules is 1.8v.  For those who are not familiar with voltage scaling of DDR2, 2.5v to DDR2 would be the same as pumping 3.2v to DDR.  All overclocking tests will be conducted with 2.3v, which is the highest VDIMM the majority of quality LGA775 motherboards provide.  Anything beyond 2.3v will be too much for DDR2 memory anyway.


Keep in mind that during overclocking, the latencies are as follows:  CAS-TRCD-TRP-TRAS.  A memory ratio of 3:4 is used throughout all tests.

The first thing that I aimed for was the lowest latencies allowed at a stock speed of 266MHZ.  Knowing that the XMS2 PC2-4300 Pro uses the "fatty" chips, I immediately shot for timings of 3-2-2-5.  Sure enough, the memory ran at those timings.  The memory overclocked so well that it even reached 260FSB, resulting in a memory frequency of 346MHZ.  That's the highest overclock I've ever reached with these low latencies.  The low latency overclock surpassed PC2-5400 speeds!  Perhaps Corsair's new low latency PC2-5400 memory uses these chips?  I loosened the TRCD and TRP latencies to 3 and was unable to go higher; a 5FSB increase resulted in an immediate non POST.  With even looser timings of 4-3-3-10, I reached 275FSB, resulting in 367MHZ.  At 14x275, my CPU was at a limit.  The engineering sample I have is one of the early productions and doesn't seem to allow any good CPU overclocking headroom.  The board's FSB and memory frequency were able to go higher, but the CPU would throttle so much that all benchmarks would run poorly, resulting in poor scores.  The memory is definitely capable of reaching higher speeds.  As much as I hate to provide bottlenecked overclocking results, it can't really be helped.  Using a regular 2.8GHZ processor with the same 14x multiplier will yield the same results.  Anyone want to donate an LGA775 processor with low multipliers so I can provide you all with good results?

Overclocking Results:

  • 200FSB  3:4  266MHZ   3-2-2-5
  • 200FSB  3:4  266MHZ   3-3-3-8
  • 260FSB  3:4  346MHZ   3-2-2-5
  • 275FSB  3:4  367MHZ   4-3-3-10



A series of memory intensive benchmarks will be run to test the performance of our sample.  The other tests will be based on common benchmark programs, such as 3DMark and PCMark.  Real life performance differences will be tested through current games, such as Far Cry and UT2004.  Memory bandwidth benchmarks will be based off of SiSoft Sandra and Everest Home Edition.  Super PI and PiFast will also be used to test memory performance, as the benchmark benefits largely from FSB increases. 

SiSoft Sandra Memory Bandwidth

SiSoft Sandra is the most widely used memory bandwidth test.  At the same rated speed, the lower latencies did not help memory bandwidth all that much.  SiSoft Sandra seems to favor the higher frequencies when it comes to DDR2 memory.

Everest Home Edition

Much like Sandra, Everest Home Edition tests the memory's ability to read and write data in large chunks.  The results show that the lower latencies seem to help just a little with performance.


3DMark is probably the overclocker's favorite benchmark.  Unlike 3DMark2003, which stresses mainly the video card, 3DMark2001SE tests all of the system's main components.  Increasing the CPU speed, memory speed, and video card speeds will result in higher results in the final score. 

Far Cry

Since Far Cry is a game, the performance results will be very similar to 3dMark2001.  I ran the benchmark at 640x480 so the benchmark would not be too GPU dependent.  The tests under 1024x768 and 1280x1024 are there to show an approximate of what kind of frames you'll be getting.  While the results are similar to 3dMark2001 in performance, this benchmark will give more significant results, because Far Cry is extremely demanding.



Results Continued

Unreal Tournament 2004

Unreal Tournament is another popular game engine to test overall system performance.  Here, we can see the same results as Far Cry and 3dMark2001.  Like Far Cry, UT2004 was also run at 640x480 to limit GPU dependency.  The other resolutions are to give an approximate of actual gameplay performance.


PCMark is another benchmark created by Futuremark.  It tests the memory compression and decompression speeds in small to large chunks of data.

Super PI

Since the value of PI is an infinite value, Super PI is a speed test to find the digit you're looking for.  In this case, we chose the millionth digit.  Super PI benefits greatly from higher FSB as well as low latencies.


PiFast is similar to Super PI and the results can be greatly affected by a slight adjustment to the memory megahertz and latency.

From the performance charts above, it can be seen that low latencies on DDR2 isn't as beneficial as that of DDR.  Yes it does provide better performance, but it seems that higher DDR2 memory frequencies provide better results. 



Conclusion and Thoughts

Corsair got around to using the Micron "fatty" chips and came up with true low latency memory.  Although the memory is rated at 3-3-3-8, it is very well capable of reaching extremely low latencies of 3-2-2-5.  The most amazing thing about the memory is not the pretty flashing lights that show memory activity, but the ability to overclock to extremely high frequencies while maintaining extremely low latencies.  I've tested other memory using "fatty" chips and none of them have reached the same overclock as the Corsair XMS2 PC2-4300 Pro.  This is by far the fastest DDR2 memory I've ever laid my hands on.  The only problem with these modules is the price tag.  Coming in at $368, the memory is definitely not cheap.  That can't be helped, because it does come with cool looking lights that make LAN systems extremely attractive.  If you want the fastest DDR2 memory out there, then you'll definitely want these.  Don't be fooled by the specified timings and speed.  The memory is capable of much more; more than you can possibly push it to. 


  • Large heatspreaders
  • Attractive memory activity lights
  • Use of Micron "fatty" chips
  • Runs extremely low latencies
  • Overclocks extremely well with low latencies
  • Excellent performance


  • High price tag

We would like to thank Corsair for providing us the sample.  If you have any questions or comments, feel free to hit us up in the forums. You can also check out more of our latest reviews on the front page.