While Intel pushes their newest RDRAM supported chipsets, the i820 and i840, other chipset manufacturers obviously see the opportunity to provide lower priced alternatives. VIA enjoyed Intel's i820 launch delays, given that VIA provided the only 133FSB alternative for Intel's Coppermine CPU. They were able to make it into some of the top tiers product offerings because of Intel's launch disaster. Now that Intel has finally launched their i820 mainstream chipset they are still faced with the RDRAM price dilemma. RDRAM is nearly impossible to get a hold of, and once you do find it you have to shell out big bucks for it. Intel then introduced their MTH (memory translator hub) so motherboard makers could offer a lower cost platform based on the i820 (details on the MTH can be found
The 'Samurai DDR' Chipset
Micron is known for both their memory manufacturing and x86 computer platforms. They have been shipping their Samurai (non-DDR) chipset for some time now in their high-end workstation product line. Micron has made some improvements to this chipset, which is code named 'Samurai DDR'. This chipset supports DDR SDRAM, 4x AGP, 133 FSB (front-side bus), and also a 66MHz 64-bit wide PCI bus (also found on Intel's higher-end i840 based platforms). Many of you that have been following our graphics board reviews have heard mention of DDR memory on NVIDIA's GeForce product. It makes a lot of sense to support this same memory technology in a motherboard chipset. DDR stands for Double Data Rate. Its name tells it all, DDR memory provides twice the data rate as good old standard SDRAM. How does DDR memory get so much more bandwidth? Easy. SDRAM is only able to pass data on the rising edge of a clock cycle while DDR SDRAM can pass data on both the rising and falling edge thus twice the throughput. Here is a table that will compare the memory bandwidth across several platforms.
|Chipset||i440BX||VIA Apollo Pro 133 Plus||i820 RDRAM||i840 RDRAM||Samurai DDR PC200||Samurai DDR PC266|
Intel's high-end i840 chipset is the only chipset that offers a higher memory bandwidth than the Micron's DDR chipset, however, the i840 is still haunted by RDRAMs higher latencies. Micron is working hard to release this chipset sometime near the middle of 2000 and has also licensed some of their technology to VIA.