Of course, the use of Xeon processors for V8 platforms requires special mainboards. Intel recommends solutions based on i5000X (Greencreek) chipset designed for dual-socket workstations.
The key distinguishing feature of the i5000X core logic set from its predecessors is the two independent processor busses with point-to-point topology in this dual-processor system. In other words, this chipset eliminates the major bottleneck of all previous generation multi-processor systems built on Intel Xeon CPUs that were sitting on the same shared bus. This innovation increased the total theoretical processor bus bandwidth in i5000X based systems to 17GB/s for CPUs with 1066MHz bus and to 21GB/s for CPUs supporting 1333MHz bus.
Moreover, i5000X boasts another powerful tool improving the communication efficiency between the CPUs and the system memory. It features a special buffer also known as Snoop Filter that contains info on the location and acuteness of all data used by the CPUs. Since MESI protocol used to ensure caches coherency in multi-processor Xeon based systems requires each of the CPUs to keep an eye on the other processor’s bus, the use of Snoop Filter helps reduce parasitical traffic on the processor busses significantly.
Although i5000X chipset is targeted for workstations, it originates from server roots. Its server origin comes from the support of FB-DIMM DDR2 SDRAM memory modules. The chipset has two independent DDR2 SDRAM controllers, each working with dual-channel memory. So, the maximum theoretical bandwidth of the memory subsystem in case of DDR2-667 FB-DIMM memory reaches 21.3GB/s during read and 10.7GB/s during write operations. Moreover, i5000X memory controllers boast a number of interesting features that are quite demanded in the server market. For example, this chipset allows building memory module RAID arrays thus increasing system reliability and permitting to replace the failed memory modules without shutting the system down.
Since the chipset is targeted for high-performance workstations, its North Bridge supports PCI Express x16 graphics port. Unfortunately i5000X doesn’t allow splitting the PCI Express x16 bus into two PCI Express x8 busses, which could enable SLI and Crossfire support. This is one of the aspects where Intel platform yields to the competitor – AMD Quad FX.
However, it doesn’t mean that you can’t build any SLI or Crossfire configurations on an i5000X based platform. The 631xESB/632xESB South Bridge used as part of i5000X platform saves the day here. It supports two additional PCI Express x4 busses, one of which can be connected to the physical PCI Express x16 slot. Some mainboard manufacturers, TYAN for instance, take advantage of this opportunity. These mainboards have SLI and Crossfire technologies working just fine (as PCI Express x16 + PCI Express x4), because neither ATI nor Nvidia doe not prohibit in their drivers multi-GPU configurations for Intel workstation chipsets.
631xESB/632xESB South Bridge also gives the Intel V8 system two ATA-100 channels, six Serial ATA-300 channels, eight USB 2.0 ports, High Definition Audio and two Gigabit network controllers. Moreover, this South Bridge allows implementing two independent 64-bit 133-MHz PCI-X bus segments.
We decided to test Intel V8 platform using an Intel mainboard, which is quite logical. So, we picked Intel Workstation Board S5000XVN mainboard based on the i5000X chipset:
The chipset features determine the board’s ability to work perfectly fine with multi-core Xeon processors supporting 1333MHz bus and to support PCI Express x16 graphics cards. The mainboard also has two PCI Express x8 slots that are physically connected to PCI Express x4 bus, a PCI-X 100/133MHz slot and a PCI-X 100MHz slot. There are eight memory slots on the mainboard that can accommodate up to 32GB of FB-DIMM DDR2 memory working at 667 or 533MHz speeds.
Hard disk and optical drives can be connected to one Parallel ATA-100 port, two Serial ATA-100 ports supporting RAID 0, 1, 0+1 and four Serial Attached SCSI (SAS) ports also supporting RAID 0, 1, 0+1 and 5 arrays. Besides, Intel Workstation Board S5000XVN also carries two latest generation Gigabit network controllers and a dual-channel HD audio codec.
The features of Intel Workstation Board S5000XVN allow using it not only for a powerful workstation, but also for an enthusiast system intended for advanced media content processing. Unfortunately, you will not be able to build a high-end gaming system on this board, because it can only accommodate one graphics card.
In conclusion I would like to add that the positioning of Intel Workstation Board S5000XVN for the workstation market resulted into absence of a number of interesting features that could be very useful for enthusiast segment. In particular, this mainboard as well as other solutions based on i5000X core logic set, doesn’t allow any processor overclocking. This is another drawback we have to point out about Intel V8 system compared with the AMD Quad FX platform that gives overclockers quite a bit of freedom.