The IT industry is one of the most dynamically developing branches nowadays. CPU clock-rates are steadily increasing, companies introduce new technologies and standards. There is no sign that this process is going to slow down in any way and that's all right because the end-users are happy about it. The memory subsystem in PCs has also undergone an evolution lately. For today, DDR SDRAM memory is dominating here and we're offered three official standards of it: PC1600, PC2100 and PC2700. The numbers denote linear bandwidth in MB/sec.

Today's multimedia applications may demand even more than 2.7GB/sec memory bandwidth, though. The CPU bus bandwidth now reaches 4.2GB/sec and dual-channel DDR chipsets that could provide for appetites like that haven't yet arrived. In order to somehow solve this temporary problem, Samsung introduced a new DDR memory standard that features 200MHz (400MHz DDR) working frequency. In theory, this memory should ensure 3.2GB/sec bandwidth, but reality is more complicated. The stable work at frequency like that requires higher memory latency and, sometimes, higher power voltage. Of course, these extra allowances cannot help telling on the performance and thermal conditions of the memory modules. This may be one of the most evident reasons why JEDEC doesn't want to approve of the new standard officially. For today, DDR400 specs look as follows: 200MHz (400MHz) working frequency, 2.6V voltage (against the standard 2.5V), CAS = 3. The last number deserves a bit more of our precious attention as in real applications the PC2100 memory working at 133MHz (266MHz) with CAS = 2 was sometimes faster than higher-frequency PC2700 that worked at 166MHz (333MHz) with CAS = 2.5.

Closer Look: XMS3200

The reputation of the new standard was upheld by the Corsair Company. The well-known manufacturer of high-quality memory modules rolled out DDR400 (PC3200) memory that can work at high frequencies with low latency value. We managed to get hold of one module like that: 256MB XMS3200, which got straight into our test lab. By the way, XMS means nothing other than "Xtreme Memory Speed". The name was given not for nothing, as the company claims that the modules from XMS3200 family feel perfectly well at 200MHz (400MHz) with CAS = 2. A rather committing statement, isn't it? We'll check it out later, and now let's have a closer look at the product we've got here.

XMS3200 ships in a neat transparent plastic box that protects the module against physical damage but also allows to see the entire module clearly. The label on the box features Corsair logo and the company's web-site address. The module itself looks "cool" enough thanks to the black heat-spreader that covers the chips. There is a sticker on it that reads: CMX256A-3200C2 and XMS3200v1.1. An interesting detail: the heat-spreader is fastened to the chips not by the ordinary metal clip, but rather by means of a sticky pad. Seems like the pad also serves as thermal interface.

The PCB of the memory module is of ordinary green color and features 8x32MB memory chips from Winbond with 6ns access time. In general, the product makes a very favourable overall impression of a high-quality expensive piece. Let's see if practice proves it.

Testbed and Methods

We will run the tests in the following system:

• AMD Duron (Morgan) 1200MHz CPU;
• EPoX EP-8K3A+ mainboard;
• ATI RADEON 8500 graphics card;
• Maxtor DiamondMax D740X 40GB, 7200rpm, ATA-133 HDD;
• Creative SoundBlaster Live! Player 1024;
• Microsoft Windows XP Professional, Build 2600.

As a point of reference, we took a Êingmax TinyBGA PC2700 DDR333 CL 2.5 module. Unfortunately, this module sticks to its specs and doesn't support any working modes differing even a tiny bit from the nominal settings. As a result, it wouldn't work with CAS = 2 without any voltage increase even at 166MHz (333MHz). Therefore, we had to take only the results from the nominal mode.

As for the memory subsystem settings, we didn't limit ourselves to switching between CAS 2 and CAS 2.5, but plunged into the finest tuning: Precharge to Active, Active to Precharge and Active to CMD. Their default values are 3-6-3, but we were curious to see the system performance when these settings are 2-5-2 respectively. The Bank Interleave option was always "4 bank"; the DRAM Command Rate remained "1T".

SiSoft Sandra Professional 2002 and the world famous Quake 3 Arena were our benchmarking software packages. The latter was chosen as a real gaming application sensitive to memory subsystem performance. To tell the truth, three years after release Quake 3 Arena is hardly an exciting game, but it remains an excellent benchmark ever since. Moreover, many popular games are based on its engine so our choice is justifiable.

Performance

SiSoft Sandra 2002

We'd like to say beforehand that SPD in the Corsair module is programmed according to the PC2700 standard, as there is no official PC3200 standard so far.

The results shown in the diagram are quite interesting. First of all, we would like to point out a small advantage of the Kingston module in the CAS 2.5 3-6-3 mode. The advanced manufacturing technology of TinyBGA chips seems to have contributed to it. Unfortunately, the Duron CPU was limiting the maximum results due to its small L2 cache. Besides that, the test results look pretty ordinary: higher frequency and lower latency lead to higher linear bandwidth. The maximum bandwidth was reached at 200MHz (400MHz DDR) and most aggressive timing settings. An interesting fact is that all the tests were run with 2.5V memory voltage, and only in case of aggressive timings selected at 200MHz (400MHz DDR) we had to increase the voltage up to 2.7V (a little higher than the DDR400 standard, 2.6V).

So, we can confirm that the Corsair XMS3200 module does work at 200MHz (400MHz) frequency with CAS = 2, but all the other memory subsystem settings shouldn't be aggressive unless you want to raise the memory voltage. By the way, it was possible to run the tests through with CL 2, 2-5-2 settings at 2.6V voltage, but in that case the overall system stability left much to be desired.

Quake 3 Arena

As we've mentioned above, this game is an excellent benchmark as it loads to the maximum all the key system units, such as the CPU, the buses between the CPU, chipset North Bridge, memory and AGP, the graphics subsystem, etc. As a result, if any of the mentioned above components speeds up, it immediately tells on the overall system performance.

The rather low result at 200MHz (400MHz DDR) with 2.5 3-6-3 settings catches our eye. This once again proves that lower-frequency memory with low latency can outperform higher-frequency memory with high latency in real applications. The explanation is simple. In Sandra we check the maximum bandwidth possible just pumping a data block at the highest speed. In real applications, blocks of different sizes and located at different addresses are processed, so we need access time rather than bandwidth. And access time directly depends upon latency settings. All the other results are predictable: we have the maximum performance at 200MHz (400MHz DDR) with the most aggressive settings. We would also like to mention that the temperature of the module remained acceptable when we raised voltage, although it nevertheless was a little higher than in the nominal mode. This is one more proof of the highest quality of the tested Corsair XMS3200.

Conclusion

Unfortunately, we couldn't check the overclocking potential of XMS3200 as the CPU we had at that moment just wouldn't work anything over 1200MHz, but we have every reason to believe that this module has some frequency reserve, judging by its excellent characteristics. 200MHz (400MHz DDR) with the most aggressive settings does impress, really. XMS3200 memory modules are definitely the fastest DDR DIMM modules today and are the best choice for those who want to squeeze the utmost out of their PCs. Extreme overclockers and hardcore gamers may rejoice: that's their memory!

Our tests proved that Corsair XMS3200 is a really high-quality product, fully compliant with the declared specs. And even more! It's a real pleasure to use this product. Of course, XMS3200 memory modules cost more than ordinary PC2700 or PC3200 modules, but that's quite reasonable. Your money buys quality here.

Highs:

• Highest performance;
• Highly stable operation;
• Efficient heat-spreader;
• Highest reliability, a trademark of Corsair;
• Product-life warranty from the manufacturer.

Lows:

• High price.