Intel Developer Forum Conference - Spring 2001: Part 1

Enter the Grand Champion HE

The Pentium 4 and Xeon's FSB truly only runs at 100MHz; the bus is "quad-pumped" meaning that the peak effective bandwidth is equal to that of a 400MHz bus but it truly operates at 100MHz.  From talking to motherboard manufacturers, it is very difficult to implement a DDR based design where the memory bus frequency and the FSB frequency aren't synchronous.  This translates into the only DDR SDRAM that could be paired up with the P4's bus being PC1600 DDR SDRAM or as Intel likes to call it DDR200 since it operates at 100MHz.  DDR200 SDRAM "only" yields as much memory bandwidth as a single channel PC800 RDRAM solution, 1.6GB/s in comparison to the 2.1GB/s of DDR266 (PC2100 DDR SDRAM).  This is where ServerWorks shows off their skills.

The Grand Champion HE chipset supports up to 4 Intel Xeon processors and to feed them, features a 4-way interleaved DDR200 memory bus. 

(100MHz operating clock) * (2 transfers per clock) * (64-bit wide bus) = 12.8Gbps = 1.6GB/s memory bandwidth for PC1600/DDR200 SDRAM

(1.6GB/s memory bandwidth) * (4-way interleave) = 6.4GB/s total memory bandwidth for Grand Champion HE

In order to provide for this incredible memory subsystem, the Grand Champion HE features a Northbridge with close to 1000 pins as well as 5 chips that together make up the memory controller subsystem. 

The Grand Champion HE supports up to three PCI-X buses (the number of buses is directly proportional to the number of PCI-X controllers that are present on the board) and it also features a Southbridge which is ATA/100 compliant however is currently only working at ATA/66. 

Quad Intel Xeon platform running on a Grand Champion HE Reference Board

Click to Enlarge

ServerWorks is also not interested in any of the incremental DDR speed increases over the next few months.  Remember, DDR200 is the only thing they can use with the 100MHz Quad-pumped bus.  Whatever DDR technology they implement must run at an initial frequency of 100MHz.  The other option they mentioned was support for DDR400, which would be DDR SDRAM running at 200MHz but effectively transferring at the same rate as the quad-pumped 100MHz FSB.  They are talking to memory manufacturers about it, however it is still at least a year away from actually being a viable option.

Publicly ServerWorks is stating that their Grand Champion HE will begin shipping in Q3 of this year, however they told us that when Intel has a chip, they would have a chipset.  Whether that means Q2 or not is anyone's guess.