1. Introduction
Corsair has earned a reputation of consistently being first to market with quality, leading-edge products that support new computing platforms and technologies. Every Corsair memory module is specifically designed for rock-solid performance under the most demanding of applications. Corsair has been a leader in the design and manufacture of high-speed modules since 1994. "Our focus has always been on supporting the special demands of mission-critical servers and high-end workstations, as well as the performance demands of extreme gamers."
Corsair is a trusted supplier to many computer manufacturers such as Intel, Tyan and SuperMicro for their server platforms. Since mid-2003, Corsair has been involved with DDR2 development through JEDEC, a technology association that develops standards for the electronics industry.
The company's flagship memory products are the XMS (Xtreme Memory Speed) family which is designed for the unique demands of the serious gaming community. The XMS memory line has become the world's most awarded memory, garnering more awards and Number One rankings from review sites and user polls than any other performance memory. The XMS family encompasses XMS2 DDR2, including modules that have broken world speed records; XMS Xpert, the first modules with real-time display of parametric data; Pro Series, gaming memory with real-time activity LEDs; and XMS Classic with black or platinum heat spreaders.
- Memory Description & Specs
The CM2X512-8000UL is a 512 MByte, two-rank DDR2 SDRAM DIMM designed for
extreme speed. According to the manufacturer, this module delivers outstanding performance in the latest generation
of DDR2-based motherboards while it has been tested extensively in multiple DDR2
motherboards to ensure compatibility and performance at its rated speed. This
memory has been verified to operate at 1000MHz at the low latencies of 5-4-4-9 at 2.2
volts. This module is also available in matched pairs of "TwinX" modules tested as a
set in a dual channel DDR2 motherboard.
Features
- 512 Megabytes of memory in a 240-pin DDR2 DIMM
- Implemented using 64M x 8 DDR2 SDRAMs
- 100% tested at 1000MHz in high performance DDR2 motherboards
- Legendary Corsair reliability and service
- Lifetime warranty
Test Specs by Corsair
- Each module is tested in an Intel-based motherboard at 1000MHz
- Tested at at the low latencies of (5-4-4-9) at 2.2V
- SPD programmed to DDR2-800 5-5-5-15
2. Test Configuration & System
After installing the two Corsair modules in our test system, we ran CPU-Z in order to see how they were identified by WinXP (SP2).
According to Corsair, the SPD should be seen as DDR2-800 5-5-5-15. What we saw was DDR2-600 5-5-5-15 or DDR2-800 5-5-5-18. The CPU details were:
The first tests ran with these settings. Then we set the Corsair modules to 1000Mhz with timings 5-5-4-9, according to the specifications. In order to achieve this, we had to increase the FSB of the CPU as well as the memory and the Vcore voltages.
In order to be sure that the memory was running without problems at this speed, we used Memtest86, latest version. And indeed, all tests finished successfully without reporting any errors. The memory bandwidth according to Memtest86+ was 4326MB/s. This was the second setup we used for our tests, since it was the highest setting for the memory. We also tried to set it a little bit higher but Memtest86+ reported several errors during the fifth test.
Finally, we chose to use another setup for our review. This time, the memory would be running at 800Mhz, as it should be according to SPD. One more time, Memtest86+ finished without reporting any errors.
Here's a rundown of our testbed:
System Specifications
CPU: Intel Pentium 4 3.73Ghz Extreme Edition
Cooler: Thermaltake Golden Ord II
Case: Antec
Motherboard: Asus P5WD2 Premium
Power supply: CoolerMaster 450W
Memory: Corsair CM2X512-8000UL (dual channel)
VGA: Asus N6800GT PCI-E
Hard Disk Drive: WD800JD 80GB 7200RPM
OS: Windows XP Pro SP2
Drivers: 7.1.8.4
DirectX: v9.0c
Benchmarks & Applications used
- Memtest86+-1.60
- Sisoft Sandra 2005
- PcMark04
- Performance Test V5.0 ( PassMark)
- Half Life 2 - VST
- CPU-Z v1.29
3. SiSoft Sandra 2005
SiSoftware Sandra is a 32 and 64-bit Windows system analyser that includes benchmarking, testing and listing modules. It tries to go beyond other utilities to show you more of what is really going on under the hood so you draw comparisons at both a high and low-level in a single product.
You can get information about the CPU, chipset, video adapter, ports, printers, sound card, memory, network, Windows internals, AGP, ODBC Connections, USB2, Firewire etc.
You can save/print/fax/e-mail/post/upload or insert into ADO/ODBC databases reports in text, HTML, XML, SMS/DMI or RPT format.
This version supports multiple sources of information gathering including: remote computers, PDAs, Smart Phones, ADO/ODBC databases or saved system reports.
All benchmarks are optimised for both SMP & SMT (Hyper-Threading), up to 32/64 CPUs depending on the platform.
Memory Bandwidth Benchmark
Tests how your memory sub-system compares to other systems with the same or similar memory in other systems. The benchmark is based on the well-known STREAM memory bandwidth benchmark.
We already knew from Memtest86+ that the memory was stable at 1000MHz, but SiSoft now reported extremely high performance. Even at 800MHz, the performance was good.
Cache & Memory Benchmark
Tests how your CPU cache and memory sub-system(s) compares to other systems with the same or similar CPU & memory in other systems. The benchmark is based on the Memory Bandwidth Benchmark test.
Combined Index: is a composite figure representing the overall performance rating of the entire Cache-Memory performance in terms of MB/s. The value is the logarithmic average of all the results for the entire address space. (Higher is better, i.e. better performance)
For block sizes that could not been tested - the average of previous blocks is used, thus the size of the memory (as long as it is not comparable to largest cache size) is not significant; all cache sizes are significant - larger caches will result in a higher index.
Speed Factor: is a figure representing the speed differential between the CPU’s cache and memory. The value is the ratio of the fastest cache (i.e. L1) bandwidth to the main memory bandwidth. (Lower is better, i.e. the memory is not very much slower than CPU’s cache)
As the factor is a ratio, it is useful only in comparing different CPUs and memory sub-systems rather than having a direct, physical interpretation associated to its numerical value.
4. PCMark04
PCMark04 is an application-based benchmark and a premium tool for measuring overall PC performance. It uses portions of real applications instead of including very large applications or using specifically created code. This allows PCMark04 to be a smaller installation as well as to report very accurate results. As far as possible, PCMark04 uses public domain applications whose source code can be freely examined by any user.
PCMark04 includes 4 categorized suites for benchmarking your computer. These include CPU, Graphics, Memory and a Hard Disk Drive benchmark. In our case, we selected to run only the Memory test suite.
| PCMark04 Memory Test |
| |
667Mhz
(MB/s) |
800Mhz
(MB/s) |
1000MHz
(MB/s) |
| Raw Block Read - 8 MB |
8421.7 |
8949.5 |
9312.4 |
| Raw Block Read - 4 MB |
9241.3 |
9734.1 |
10153.6 |
| Raw Block Read - 192 KB |
29748.6 |
33244.7 |
33472.1 |
| Raw Block Read - 4 KB |
49602.1 |
55073.1 |
55804.9 |
| Raw Block Write - 8 MB |
5405.8 |
5910.1 |
6079.4 |
| Raw Block Write - 4 MB |
5404.5 |
6052.1 |
6082.2 |
| Raw Block Write - 192 KB |
12624.1 |
14169.5 |
14196.1 |
| Raw Block Write - 4 KB |
12654.6 |
14202.9 |
14233.2 |
| Raw Block Copy - 8 MB |
3055.3 |
2451.3 |
3165.0 |
| Raw Block Copy - 4 MB |
3849.7 |
2773.6 |
4204.2 |
| Raw Block Copy - 192 KB |
11195.3 |
12736.3 |
12580.8 |
| Raw Block Copy - 4 KB |
12643.8 |
14184.8 |
14213.5 |
| Random Access - 8 MB |
5055.8 |
5323.0 |
5648.8 |
| Random Access - 4 MB |
5110.9 |
5257.1 |
5643.6 |
| Random Access - 192 KB |
7079.8 |
7766.8 |
7907.9 |
| Random Access - 4 KB |
12577.0 |
14135.9 |
14154.7 |
Once again, but this time according to the PCMark scores seen in the above table, the performance for the Corsair running at 1000MHz was extremely good.
5. Performance Test v5.0
- Memory Benchmarks
This suite contains a number of tests that exercise the memory sub-system of the computer. (Random Access Memory- RAM)
Memory - Allocate small block
This test measures the time taken to allocate & free small zeroed memory blocks (around 100KB block size)
Memory - Cached
This test measures the time taken to read a small block of memory. The block is small enough to be held entirely in cache (if one is present)
Memory - UnCached
This test measures the time taken to read a large block of memory. The block is too large to be held in cache.
Memory - Write
This test measures the time taken to write information into memory.
According to Passmark the difference in performance was greater when stepping up from 667MHz to 800MHz than from 800MHz to 1000MHz. In most cases, the reported results were similar for Corsair when running at 800MHz and 1000MHz.
- Advanced Memory Benchmark
Memory Speed Per Access Step Size
The first test type, ‘Memory Speed Per Access Step Size’ accesses a large block, of memory in various sized steps. First, it runs through the block of memory sequentially, accessing every value. Next it runs through the same block again, except this time it accesses every second value. On this occasion, it runs through the block twice in order to access the same amount of data as the initial step. Next it runs through the same block again, except this time it accesses every fourth value and so makes four passes. And so on, until a certain maximum step size is reached.
The size of the block of memory used for this test is one quarter the amount of system RAM. The size of the steps varies from 1 (continuous sequential access), to one quarter the size of the block of memory ( i.e. one sixteenth of the system RAM ).
| Memory Speed (MB/Sec. per Step Size) |
667MHz |
800MHz |
1000MHz |
| Block Read Speed |
41.76 |
43.88 |
46.62 |
| Block Write Speed |
27.80 |
27.24 |
31.56 |
| Click on the links above for the full graphs |
According to the specific test, there is a great difference between the three setups.
Memory Speed Per Block Size
When a computer program wants to use a section of memory to store data, it makes a request to Windows for the amount of memory it requires. Windows allocates the memory to the program ( unless system resources are very low ) and returns to the requesting program the address of the first memory slot in the allocated block. It is possible that some programs may request very large amounts of memory. The ‘Memory Speed Per Block Size’ test like the ‘Memory Speed Per Access Step Size’ test, is composed of many steps. During each step of the test, PerformanceTest requests a block of memory and runs through the block measuring the average access time. However on each subsequent step the size of the requested memory is increased, until finally a block close to the size of the system RAM is requested. In this way it is possible to observe the different access speeds for the different sizes of blocks.
Typically it is possible to see very fast memory access for blocks which are small enough to fit entirely into the L2 RAM cache, and slower access times for larger blocks accessed from main RAM. In the case where system resources are low, swapping to the disk may even be required for very large blocks.
| Memory Speed (MB/Sec. per Block Size) |
667MHz |
800MHz |
1000MHz |
| Block Read Speed |
430.86 |
484.12 |
485.33 |
| Block Write Speed |
298.91 |
335.75 |
336.33 |
| Click on the links above for the full graphs |
On the other hand, the memory speed when measured per Block size reported near similar performances at 800MHz and 1000MHz.
6. Half Life 2
Half life 2 is no doubt the most anticipated pc game of all times. Gamers having the excellence of Half Life 1 in mind, as well as the remarkable E3 demo preview, have been anxiously waiting for the much delayed release of HL2.
Physics - From pebbles to water to 2-ton trucks respond as expected, as they obey the laws of mass, friction, gravity, and buoyancy.
Graphics - Source's shader-based renderer, like the one used at Pixar to create movies such as Toy Story® and Monster's, Inc.®, creates the most beautiful and realistic environments ever seen in a video game.
AI - Neither friends nor enemies charge blindly into the fray. They can assess threats, navigate tricky terrain, and fashion weapons from whatever is at hand.
With games, the increased FSB in combination with the memory speed, boosted the frame rate.
7. Conclusion
The Corsair CM2X512-8000UL modules reported excellent performance in our benchmark tests. The results were good at 667MHz and 800MHz, but at 1000MHz they were excellent.
Corsair reaches the highest levels of performance without any compromise in timings. The highest speed of 1000MHz, was attained with the lower timings, in comparison to those at 667MHz and 800MHz with SPD.
SiSoft Sandra 2005 reported the very high score of 7602MB/s and 7619MB/s in RAM Bandwidth Integer and Floating Point respectively, while in Combined Index, the reported 13620MB/s is the highest we have seen. The high performance was also confirmed in PCMark04, with the score reaching 7636.0 PCMarks while with Performance Test v5.0, it was 631.9. In games, the increased memory speed in combination with the overclocked CPU can raise the frame rate, as happened in our HL2 test where we saw a jump of approximately 20fps when going from 667MHz to 1000MHz. And all this while Memtest86+ confirmed that at 1000MHz with 5-4-4-9 timings, operation was error free.
If you want the fastest DDR2 memory that you can buy for Intel CPU based boards, Corsair should be your choice. The retail price for the Corsair CM2X512-8000UL is close to $267 from newegg.com. Although the price sounds a little expensive, we believe that it is worth the money, especially considering the 1000MHz!
The Good:
-
Excellent performance at all speeds
- Stable performance even at 1000MHz
- Can handle Voltage up to ~2.2V without problems
- Stylish design with the black heat spreaders
The Bad:
;-)