Micron’s Upcoming Samurai DDR Chipset — First Looks — THG.RU

Introduction

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 Intel’s New CC820 Motherboard Review). Motherboards with the MTH implemented in to the design provide the support of the lower priced PC100 SDRAM. Unfortunately, along with the lower cost memory comes a huge performance decrease (-15%). Even an i820 platform outfitted with high priced RDRAM memory doesn’t really offer much of a performance advantage over 440BX based boards (details on the i820 chipset can be found Intel’s i820 Chipset Review). Well I am happy to see that Micron also recognizes these problems and is working on their new upcoming chipset code named ‘Samurai DDR’.

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.

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.

The Samurai DDR Test Platform

The Samurai DDR platform we tested was no way near a production motherboard. The motherboard was an engineering prototype that was twice the size of a typical board.

The board supported dual CPU’s, included an AGP Pro50-slot, 5 PCI slots, 2 USB ports, 2 serial ports, 1 parallel port, no ISA slots, and utilized the same south bridge as a 440BX based platform.

Even though the tested platform utilized the older south bridge, the Samurai DDR chipset was also designed to support VIA’s south bridge as well. I wished that the reference platform we had in the lab was designed using VIA’s new south bridge.

Although the performance of the older BX south bridge was decent, it lacked the important UDMA 66 IDE interface. To remove any performance deficits I might encounter with the onboard UDMA 33 IDE interface, I installed a Promise Ultra 66 PCI IDE controller. Anyway, the board ran without any problems, which amazed me since it was a prototype board running with alpha silicon!

DDR Performance Expectations

Given my experience with SDR vs. DDR graphic boards I definitely knew that DDR SDRAM memory should provide a performance boost over SDRAM. The only questionable thing in my mind was how good was the Samurai DDR chipset.

I didn’t know if the chipset would artificially hide the performance advantage of the DDR memory. I figured that the DDR platform should at least come close to the performance we saw with the i840 board in our article The RDRAM Avenger — Intel’s i840 Chipset.

Benchmark Setup

Benchmark Results

Given the short amount of time I had with the board I tried to hit both Business Application performance and 3D gaming performance. For the business side of the testing I ran BAPCO’s SYSMark98 under both Windows 98SE and Windows NT 4.0 SP6. To touch on the DDR platforms 3D gaming performance I ran the retail version of Quake 3 Arena and also Expendable. The game apps were run at 640x480x16 to eliminate the possibility of the graphics board becoming the bottleneck. For comparison’s I included results from a 440BX, i820, and i840 platform. The 440BX platform was tested with a Coppermine 700 CPU overclocked to 750 MHz, while the rest used a 733MHz part.

Business Application Performance under Windows 98SE

Looks like the Micron motherboard is able to hold its own against the fastest scoring i840.

Business Application Performance under Windows NT 4.0 SP6.

The SYSmark98 results here look very similar to those under Windows 98SE. Both the i840 and Samurai DDR chipsets pull further ahead of the i820 board.

3D Gaming Performance under Windows 98SE

The Samurai DDR platform provides the best frame-rate keeping up with the i840 platform. The BX platform is clearly outperformed by over 8 FPS even when configured with a 750MHz CPU!

The DDR platform overtakes the i840 by over 3FPS. Even though the i840 has a higher memory bandwidth, it looks like the higher memory latencies are getting in its way. The Samurai DDR chipset looks like it will make a great Quake 3 playing machine.

Summary

It looks like Micron is heading in the right direction with their upcoming Samurai DDR chipset. The upcoming chipset was able to keep pace with Intel’s high-end i840 platform through our suite of tests. Looking at the performance DDR SDRAM has to offer it makes me wonder why Intel decided against it and chose RDRAM. Manufacturing DDR memory isn’t much different than that of standard SDRAM versus the entirely new process and equipment required for RDRAM. The die size for DDR is only about 5% larger than that of SDRAM versus RDRAMs 10-15% larger die size. The price of DDR SDRAM should be much more reasonable than the outrageous pricing for RDRAM that is nearly 5 times the price of SDRAM.

Although Intel is going full force pushing the RDRAM effort there has been rumors floating around that they are working quietly on a DDR platform. If this is true RDRAM might end up a thing of the past. DDR memory looks like it has its place in the motherboard arena. Besides VIA and Micron driving this new memory technology the Platform2000 conference will also be discussing DDR technology and standards. If you interested in learning more about DDR memory and other platform strategies you might want to check it out.

As I look at the performance of this upcoming DDR chipset it only confirms my opinion to stick with either a 440BX or VIA based platform for now. Although the i840 chipset shows a reasonable performance advantage over the 440BX, it still can hardly provide enough for the cost of its RDRAM memory.