Friday, November 1, 2002
Introduction
VIA Technology just announced the cut back on DDR266 chipset production favoring DDR400 chip set. SIS has been shipping DDR400 chipset since March and nForce chipset by Nvidia also has a DDR400 memory interface. They have been shipping for a while and is geared for the AMD MPU. The obvious exclusion is Intel, the largest chipset maker in the world. Why is that and what''s happening? Careful examinations of the landscape review the following scenario.
"Technically Speaking"
The DRAM companies are capable of producing DDR400 with their latest die shrank to 0.13 micron process. They are happy to offer it. However, the system engineers are not so optimistic. They have to meet the worst-case simulations and timing margin. Micron and IBM engineers have been saying that there is no way to meet timing margin with existing system technologies. BGA, FR4, 3 balanced DIMM sockets are the technical roadblocks. Micron engineers declared that PC3200 (DDR400) DIMM would only work comfortably in 1-slot systems. Samsung''s Lee classified it as a boutique memory only for selected specialty applications.
DRAM Manufacturer Speaks Out
"We will sell anything the customer wants and is willing to pay for " quoted several DRAM manufacturers having announced delivery of DDR400 chips. Video accelerator cards are using it and over clocking to more than 400Mhz. These super-RAM prices will stay high until the 0.13 micron process has finally sunk in. On the other hand, DDR2 is up and coming on the horizon resulting in the window of opportunity for DDR400 cutting short and of course the largest drawback is lack of endorsement from Intel.
So, Why is it making so much excitment?
Taiwanese chipset companies have limited products to offer and they want to carve out a niche for their own market. However, they are not the in the design mode but are followers of design and had ignore the system issue aspect analysis that JEDEC so meticulously carried out. Taiwanese produced 75% of the motherboards in the world, they are just copycats with very little innovation and market breaking capability but by simply concentrating on impulse marketing. On the other hands, IBM and Intel have to wait for the confirmation and the market sentiment. As a result of the confusion, the industry is already experiencing a lot of failure reports on DDR400 in the market.
DDRI vs DDR2
While DDR2 is supposed to have prototypes by early 2003, its speed will likely start at 533Mhz. Why does DDRII work better than DDRI? New DDRII features include Post Cas, ODT and OCT, and differential DQ lines to minimize noise and maximize system timing margin.
Overclocking vs Normal clocking system
Most 400Mhz systems on market are overclock systems and do not recognised 400MHz memory as standard operation. One must overclock the processor and the memory together to gain the 400Mhz mode of operations. Therefore, it is configured at users'' own risk.
Conclusion
Instead of 400mhz, there will be dual channel 333 DDR to give more bandwidth. DDRII will come in before the DDR400 process is perfected. DDR400 will remain for specialty graphics and boutique applications.
On another cautious note, Micron''s Lee said the faster, 5ns memory cycle time of DDR400 means the chips will consume 20% more power than DDR333 devices of comparable density. "Thermal issues become a great concern at these higher clock rates," he said.
By: DocMemory
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