Introduction
Introduction
We recently reviewed a stick of some Crucial PC2100, and were very impressed with it as it was able to run at 146 MHz at Cas2, and at 147 MHz at Cas2.5 (read the review here). Only a few weeks after our review Corsair announced some XMS2400 (PC2400) Cas 2 DDR RAM. That these sticks are called XMS2400 (XMS stands for "eXtended Memory Speed") or PC2400 basically refers to the fact that these sticks will let you run your DDR RAM at 150 MHz FSB (300 MHz effectively). And not only will they run at 150MHz FSB, they are promised to do that at Cas2!  . All other DDR RAM sticks from other manufacturers are rated at Cas2.5.
According to DDR RAM standards, there is no such thing as PC2400. Only PC1600 and PC2100 have been formally specified (although JEDEX are working a new standard, PC2700, which will allow you to run a healthy 166 MHz FSB (333 MHz effectively)). As the PC2400 sticks of Corsair RAM should be able to put out a healthy 2.4 GB/sec. (compared to PC2100’s 2.1 GB/sec.), the PC2400 name seems justified.
Here’s a little from the press release:
Corsair's XMS2400 modules go beyond the performance dictated by industry-standard specifications such as PC1600 and PC2100. The additional speed provides additional performance margin in standard configurations, and provides the ultimate in fast memory for enthusiasts who want to squeeze the maximum possible performance out of their hardware.
Corsair's initial DDR offering includes XMS2400 modules with memory sizes of 128 MByte and 256 MByte. Both modules have been extensively qualified in specially configured motherboards running at 150 MHz (300 MHz memory data rate) and higher. All XMS2400 modules are 100% tested on 150/300 MHz test platforms. Corsair Micro
Corsair is a company that doesn't need a long introduction. Most of you should be familiar with them. They have been offering quality memory solutions for a long time and are a trusted name for businesses, as well as for overclockers, due to their high performing memory. Most of you will know them for their tweaked/guaranteed PC133 SDRAM.
As DDR RAM was introduced, they moved into that area as well, and didn't just want to follow the standard specifications, but rather stay at the cutting edge of the technology.
DDR RAM – what you need to know...
DDR RAM comes in three flavours: PC1600, PC2100 and now PC2400. PC2400 is used in a system with a 150 MHz (300 MHz) FSB, PC2100 SDRAM is used in systems with a 133 MHz (266 MHz) front side bus, and PC1600 SDRAM is used in systems with a 100 MHz (200 MHz) front side bus.
What makes DDR SDRAM special is that it reads information on both the rising and falling edge of the CPU's clock cycle, which theoretically doubles the speed of memory processing over standard SDRAM. As you will see on the next page, the speed isn't exactly doubled, but it does perform a lot better than standard SDRAM.
Motherboard
As my Asus A7M266 doesn’t have multiplier setting there was no chance I could crank it up over the 147 MHz I have reached so far. This is not due to the Asus A7M266 being unstable over those speeds, it’s simply so that my 1 GHz Thunderbird AXIA CPU (10x100) can’t do more than 1470 MHz (10x147). So blame AMD . And Asus for not including a multiplier on the A7M266. As I have uttered before: WHY, WHY, WHY !?!?!?
Well, as there was no way I was going to review this RAM without investigating if it could do 150 MHz Cas2 (or more), I was forced into a buying situation. I needed a motherboard with a multiplier setting. My local hardware store had some MSI K7T266 Pro’s in stock, so that became my choice (expect a review soon).
With the bios rev1.0 this board could only do 153 MHz FSB, but fortunately enough, there was a new v1.2 bios out that included FSB options up to 164 MHz.
Packaging
Corsair RAM comes well packaged as can be seen in the above picture. It is packaged in a plastic box, where it is kept safe. (Click to enlarge.)
Appearance
Picture of the front
(Click to enlarge.)
The chips that are on these PC2400 sticks are the same as the ones used on the Crucial RAM, namely Micron chips. They are from week 18 on the PC2400, whereas the Crucial RAM was from week 10.
Picture of the back
(Click to enlarge.)
Picture of the the Corsair, Crucial and Thermaltake RAM, aka The Three Stooges!
(Click to enlarge.)
Test Setup
| HARDWARE | | CPU | AMD Thunderbird 1000MHz AXIA Y Stepping (Week 10) | | Cooler | ThermoSonic ThermoEngine V60-4210 | | Motherboard | MSI K7T266 Pro (KT266 chipset) Bios v1.2 - Using High Performance Setting | | Memory | 2x128MB PC2400 Corsair SDRAM
256MB Crucial PC2100 SDRAM | | Hard Drive | IBM 40GB 60GXP 7200 rpm | | Video Card | Leadtek Winfast Geforce 256 32MB SDRAM | | Sound Card | Creative Labs SoundBlaster Live Value | Network Interface Card | | |
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| SOFTWARE | | Operating Systems | Windows ME and Windows 2000 | | Drivers | Nvidia 6.50 DirectX8.0
VIA 4-in-1 V4.31V | | Benchmark Software | SiSoft Sandra Pro 2001SE |
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