CompuStocx XAC-1200 2GB Kit (2x1024MB) PC2-9600/DDR2-1200 Memory Review


The introduction ...

With the CSX XAC-1200 2GB kit we would like to take a look at the first DDR2-1200 memory kit from CompuStocx.
CSX Diablo DDR2-1200 / PC2-9600 memory modules are specificated for memory voltages up to 2.40 V and thanks to the Micron D9GMH chips, this RAM can already operate as DDR2-1066 / PC2-8500 modules starting from 1.90 Volt.
This high performance DDR2 RAM kit was able to reach nearly the top speed of all modules tested so far and
satisfied with very high overclocking results.




Thanks for the support ...

Many thanks for the support with the CSX XAC-1200 Diablo 2GB PC2 9600 / DDR2 1200 CL5 kit with the designation
CSXO-XAC-1200-2GB-KIT by the manufacturer CompuStocx.

The 2 GB kit contains 2x 1024 MB 240-pin DIMM DDR2-1200 (PC2-9600) memory modules and has a price of
approx. 155 Euro (11/2007).
They're available in the CompuStocx Shop and at our sponsors.



The supply of the two 1GB PC2-9600 memory modules ...

The two very well protected memory modules are delivered in this packing:



That is contained in the scope of delivery ...

CompuStocx supplies the two memory modules without troubleshooting guide or installation guide.
A datasheet and an installation guide for less experienced users would be desirable.

Here is a picture of the two contained XAC-1200 memory modules:

CSX published a new revision of these modules with a little bit changed Design and a short installation guide in the Inlay.

Latest module Design and installation guide see picture:



The technical data ...

Manufacturer CompuStocx / CSX
Article number CSXO-XAC-1200-2GB-KIT / 10014113
Memory DIABLO 2GB kit (1024MBx2)
Package 240-pin DIMM
Type DDR2 PC2-9600
Configuration 128Meg x 64
Error correction NON-ECC
Speed DDR2 1200 (600 MHz * 2)
Voltage 800MHz 1.8 Volt
1066MHz 1.9 Volt
1100MHz 1.95 Volt
1200MHz 2.4 Volt
Memory timing 5-5-5-16 (Tcl-Trcd-Tras-Trp)



Characteristics and other features ...

The memory modules are provided on a green plate with black passive heatsinks (heatspreader) to get lower temperatures,
also with higher frequencies and/or higher voltages.
A very good heatsink and good contact between heatsink (heatspreader) and memory chip is especially important with these CompuStocx DDR2-1200 overclocking modules, because a high voltage and/or frequency could destroy the DDR2 RAM without a good cooling.
The heatspreader with additional cooling lamellas has a nice finish and is pressed very evenly to the thermal pads of the memory chips and offers a good heat dissipation.
Unfortunately the test modules comes without EPP (Enhanced Performance Profiles) support.
The additional entry in the SPD EEPROM would be helpful on those high-end overclocking modules to get automatically
best timings and frequencies for overclocking on latest generation motherboards with EPP support.



Benchmark values and test results ...

Let us begin with the most important part of the test report, because the optical characteristic and packing is of course
rather secondary and the highest possible stable performance is the most important factor.
The test results are based on an ASRock AM2XLI eSATA2 SLI motherboard with an Athlon 64 Socket AM2 3000+
CPU on different frequencies depending on the reference clock for the different memory benchmarks.
Furthermore the memory modules were tested on another reference board to test the high frequency with higher voltages.
The multiplier adjustment remains on 9x with all frequencies, because an adjustment for the CPU in half multiplier
steps would be too inaccurate to get nearly the same CPU frequency for all tests.

Microsoft Windows XP Professional SP2 is used as the operating system.
The stability was examined with the software Memtest86 and SiSoft Sandra Lite 2007.SP1 program is used for all
benchmarks, since it offers extensive adjustments and a fast result comparison.
BTW. the latest SiSoft Sandra 2008 version is available on our download server and can be downloaded much faster - ALL benchmarks are also included in the free Lite version.

First the maximum possible frequency of the memory module was determined.
The memory frequency was increased in small steps with a fixed memory timing of 4-4-4-10 2T and default memory voltage, as long as the detailed memory test with Memtest86 runs without any errors.
This quite long testing time ensured that this frequency works really stable with these modules.

The highest possible frequency with 4-4-4-10 (Tcl Trcd Tras Trp) timings was stable with enormously high 469 MHz.

It's possible to run much higher frequencies with increased voltages or lower timings, because the frequency values
and timings depends directly from each other.
Officially CompuStocx specify a memory voltage of 1.80 to 2.40 Volt without loosing the warranty.
2.40 Volt is supported on some motherboards, so the maximum manufacturer frequency of 1200 MHz (600 MHz x2) on CL5
is not possible on all mainboards.
It's necessary to have 2.40 Volt (instead of 1.80 Volt!) to reach DDR2-1200 performance.
For this test additionally a slightly modified reference board (Foxconn C51XEM2AA) was used.
This reference board supports up to 2.50 V Vmem and this offers a performance of much more than 600 MHz (DDR2-1200).

The highest possible frequency with default DDR2 voltage was compared with two settings.
On the one hand 469 MHz with SPD values (these are programmed in the SPD IC by the manufacturer),
and on the other hand 200 MHz (x2) with SPD values.

By the way, the "Memory Bus Range" is no benchmark value, but this value is quite simple to calculate by the
frequency and is useful for the benchmark comparison.


Here're the benchmark results:

RAM Range Int Buff'd iSSE2
Memory bus range
469 MHz
fix (4-4-4-10 2T)
6560 MB/s
15008 MB/s
469 MHz
SPD (5-5-5-16 2T)
6500 MB/s
15008 MB/s
200 MHz
SPD (4-3-3-8 2T)
4724 MB/s
6432 MB/s


Here's a diagram of the benchmark values:


Here is a direct benchmark result comparison of some DDR2 and DDR memory modules:

The result of the CompuStocx CSX XAC-1200 Diablo is currently (11/2007) on position 2 of all tested RAM kits!

In view of the enormously performance in the upper segment, this is a awesome result. And with the manufacturer release of voltages up to 2.40 Volt, the top position is inofficially exceeded.
The benchmark comparison is officially only done with default voltage which is supported on all motherbaords.
Everyone who like to get a higher frequency or latency, need the often mentioned higher Vmem.


Result and general impression ...

The CompuStocx Diablo CSXO-XAC-1200-2GB-KIT offers a very far spectrum for overclocker regarding the frequency and timing. Because the maximally certified voltage of 2.40 V - instead of usual 1.80 V - offers an optimal adjustment of the frequency and the RAM timing on high-end motherboards.
The missing EPP entry in SPD of the test modules was not good and will be hopefully added in newer revisions of these high-end DDR2-1200 modules very soon. The EPP entry is not essential for experienced overclockers since all values can be selected manually in the BIOS, however the automatically timing adjustment is much easier.



Read on in the hardware test area with several hardware reviews ...


All pictures and article copyright 2007