TwinMOS 256MB DDR400 Memory Review

JEDEC have only just approved the PC2700 memory standard, and we are already seeing a lot of memory manufacturers coming out with their DDR400 modules even though JEDEC are still in the works of approving it. Asher "Acid" Moses takes a look at one such PC3200 module from up and coming Taiwanese company, TwinMOS. Does it have what it takes to compete with the well known memory brands in overclocking tests? Read on and find out!
Asher Moses
Published Thu, Oct 3 2002 11:00 PM CDT   |   Updated Tue, Apr 7 2020 12:25 PM CDT
Rating: 95%Manufacturer: TwinMOS

TwinMOS DDR400 - Introduction & Specifications

IntroductionAlthough there isn't yet an official JEDEC specification for DDR400 memory, we are already starting to see DDR400 modules popping up all over the place from a variety of different manufacturers. In the past we have taken a look at DDR400 modules from Corsair and Kingmax, and each were impressive in their own way. While Corsair's module is directed at hardcore overclockers, Kingmax's product is targeting the mainstream, more price conscious market.The latest DDR400 module to hit our labs is manufactured by TwinMOS and you could say it is in between both the Corsair and Kingmax modules. While it does offer very impressive overclocking potential, it doesn't cost you the premium that Corsair's memory does.What to know more? Please, read on...Specifications Memory amount: 256MB Access time: 5.0ns Implemented using 32M x 8 DDR SDRAMs with 5.0ns access time 100% tested at 200MHz in high performance systems Six-layer construction Latency: 2.5-3-3-3-1T if one module is installed Latency: 2.5-6-3-3-2T if two modules are installed

TwinMOS DDR400 - Taking A Closer Look

Taking A Closer Look- DDR Naming SchemeA DDR memory module is given two names according to both its maximum transfer rate and speed. In the case of TwinMOS's DDR400, its two ratings are PC3200 and DDR400. PC3200 is the maximum transfer rate of the module, which in this case is 3.2GB/sec. On the other hand, DDR400 is the speed of the module in MHz, which in the case of DDR400 is 400MHz (200MHz DDR).The effective bandwidth of the module is worked out by taking its speed rating (400) and multiplying it by 8. We multiply the speed rating by 8 because DDR modules are 8 bytes wide. So, the formula for TwinMOS DDR400 memory would be: 400 * 8 = 3200 or PC3200.- The Module
As you can see, TwinMOS have not prettied up their module with any fancy heat spreaders or colored PCBs. Both of these do nothing to the modules' performance and if anything, increase its price. The module is single sided, meaning that memory chips have only been placed on one side of the module. In theory, this is said to be great for overclockers as there is a much less chance of stress induced errors.
TwinMOS have decided to go with Winbond BH-5 chips for their DDR400 modules. As mentioned in the specifications on the previous page, the chips are rated at 5.0ns and judging by reports from around the enthusiast community, these new memory chips should yield some very impressive overclocking results. Also of note is that the memory chips are arranged in an 8x32MB fashion.
Unfortunately, TwinMOS are not guaranteeing that you can run their DDR400 memory at a CAS Latency of 2, unlike Corsair. However, we had no problem running our module at 200MHz with a latency of 2 and there is no reason why anyone else shouldn't be able to either.

TwinMOS DDR400 - Benchmarking

Benchmarking- Test SystemProcessor: Intel Pentium 4 2.4GHz (18x133)Motherboard: Abit SR7-8X (SiS648)Memory: TwinMOS DDR400 256MB, Corsair XMS3200 256MBVideo Card: Abit Ti4200 OTES @ 310/600MHzSound Card: Creative Soundblaster Audigy Platinum eXHard Disk: Seagate 40GB 7200RPMOperating System: Windows 2000 Professional SP2Drivers: nVidia DetonatorXP v40.41, DirectX 8.1Software Used: SiSoft Sandra, 3DMark2001 SEResults - SiSoft Sandra Memory BenchmarkSiSoft Sandra (the System ANalyser, Diagnostic and Reporting Assistant) 2001 is a synthetic windows benchmark that features different tests used to evaluate different PC subsystems.
Results - 3DMark2001 SE 1024x768 32-bit3DMark2001 SE is the latest installment in the popular 3DMark series. By combining DirectX 8.1 support with completely new graphics (including the GeForce4), it continues to provide benchmark results that empower you to make informed hardware assessments.
As we expected, both modules performed virtually identically in all tests performed. This is due to the fact that they were both running at the same speed and had identical CAS timings. Where we will see a difference between the two modules is in our overclocking results. Who came out on top? Keep reading...

TwinMOS DDR400 - Overclocking & Conclusion

OverclockingDue to the fact that the Abit SR7-8X motherboard and SiS648 chipset are limited to no more than a 145MHz FSB, for overclocking we swapped this board with Abit's IT7 based on the i845E chipset. Using a 3:4 CPU:DRAM ratio and bumping up the FSB to 150MHz, we had our memory running at 200MHz. We then continued to increase our FSB until we reached a maximum of 165MHz. Here the memory was running at 220MHz and we feel as if it could have gone a lot further. However, this time it was not the motherboard that was holding it back, but rather the CPU.The Corsair XMS3200 was also able to reach a speed of 220MHz, which is unsurprising considering that the memory is directed at hardcore overclockers. Both modules were able to run with a CAS latency of 2 at these speeds.From these overclocking results we can conclude that both modules will be able to handle almost any speed you throw at it, as your CPU and motherboard will most likely bomb out way before the memory actually does.ConclusionOverall, we were very impressed with TwinMOS's DDR400 memory. It is fast, stable and most importantly, can withstand high clock speeds, making it ideal for overclockers who like to gain the maximum performance out of their hardware. At a price of around AU$200 (US$100), it is also quite a bit cheaper than the Corsair XMS3200 memory we checked out earlier this month.The bottom line is, if you are looking for the same performance as Corsair XMS3200 without the added cost, you should definitely check out TwinMOS's DDR400 memory. The only disappointing aspect about this module is its availability, and at the time of writing this review we could only find 512MB modules in our favorite online stores.- Pros Fast Highly overclockable Can run at agressive CAS timings Cheaper than Corsair's XMS3200- Cons AvailabilityRating - 9.5/10

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