X-bit labs

Workstation Processors Duel: AMD Opteron against Intel Xeon (page 8)

Category: CPU

by Ilya Gavrichenkov

[ 12/21/2005 | 08:44 PM ]

Mainboards

Supermicro X6DA3-G2

We will first talk about the mainboard we tested the Intel Xeon processors with. It is not a problem to find a dual-processor platform for single- and dual-core AMD Opterons, but Socket 604 mainboards for dual-core Xeons on the Paxville core are rather rare. Intel’s release of the Paxville-based processors kind of gave a headache to the platform manufacturers because the new CPUs were incompatible with older Socket 604 mainboards because of the increased power requirements. The manufacturers had to quickly update their products, reinforcing the voltage regulator, and this explains why there are not that many mainboards that support dual-core Xeons in retail shops.

Moreover, we couldn’t go on with just any dual-processor mainboard that supported the Paxville-based Xeon because the mainboard for a high-performance workstation must also have a graphics bus for a professional graphics card. This requirement limited our choice to platforms on the Intel E7525 chipset as it is the only chipset from Intel for dual-processor systems to support the 800MHz FSB and a PCI Express x16 bus.

So we hadn’t much choice and the Supermicro X6DA3-G2 was almost the only mainboard we could find that complied with our requirements. Supermicro is currently the only company that has actively supported the launch of the dual-core Xeon. While the other manufacturers just announced one or two mainboards with added support of the new processor, Supermicro updated almost the entire product range and added not only a reinforced CPU voltage regulator but also such an interesting feature as Serial Attached SCSI to its mainboards.

So let’s have a closer look at the Supermicro X6DA3-G2 mainboard. As we mentioned above, it is based on the Intel N7525 North Bridge which supports two Intel Xeon processors with 800MHz FSB, dual-channel registered DDR2-400 SDRAM and PCI Express.

The Supermicro X6DA3-G2 has each of the listed features, too. The mainboard carries two Sockets 604 for Intel Xeon processors of any type – single- and dual-core models with a 533 or 800MHz FSB. The power circuit is the most important component here, and the mainboard has two independent four-channel voltage regulators. The MOSFETs employed in this circuit do not have any heatsinks on them, although we would think that heat-spreaders could be a good idea. The load-bearing elements become very hot when the mainboard works with two dual-core Xeon 2.8GHz CPUs that have the highest power consumption.

The Supermicro X6DA3-G2 offers eight DDR2 DIMM slots for registered DDR2-400 SDRAM modules with up to 2GB capacity each. The maximum amount of memory you can install is 16 gigabytes. The memory access is dual-channel and the slots belonging to the different channels alternate on the PCB. The peak memory bandwidth is 6.4GB/s, i.e. equals the peak bandwidth of the 800MHz FSB that connects the chipset with the CPUs.

Intel’s E7525 chipset endows the reviewed mainboard with support of ECC and Memory RAS (Reliability, Availability and Serviceability) technologies. This not only ensures reliable operation of the memory subsystem but also helps avoid stoppages when a module fails.