Fujitsu Primergy RX900 S1 review

Since Intel launched its Xeon 7500 family of processors earlier this year we’ve exclusively reviewed a number of four-socket systems but Fujitsu’s new Primergy RX900 S1 takes the honours as the first eight-socket production server to market. In our Xeon 7500 benchtest in our sister title PC Pro we alluded to a ‘glue-less’ design that doesn’t require a custom chipset. This allows system designers to expand beyond four sockets just by using the onboard QPI (Quick Path Interconnect) links and the RX900 S1 is the first to have this in a single system.

IBM does have an alternative method of creating an eight socket system. However, as we saw in our exclusive review of its x3850 X5 , the base system is a four-way server which is expanded by adding a second x3850 and linking the two together using IBM’s X5 scalability cable kit. The RX900 S1 is a far simpler solution as everything you need to create an eight-socket server is inside its 8U chassis. This allows it to scale easily to 64 physical and 128 logical processor cores.

The base system starts where 4-socket systems end as it comes with a minimum of four cold-swap processor/memory riser cards. You can easily expand to six or eight sockets as demand dictates and the sixteen DIMM slots on each card allow memory to be expanded to a mighty 2TB of DDR3 when 16GB modules becomes available.

The RX900 S1 offers a range of memory reliability features as, along with interleaving, it supports both intrasocket and intersocket memory mirroring. This allows mirroring to occur within the memory controllers on one processor or across different processors but the latter is only supported when you have six or eight riser cards.

Memory sparing is not supported on the RX900 S1 but you do get Hemisphere Mode. This feature of the Xeon's chipset aims to improve latency and performance. It essentially allows a processor's memory controller to know about the contents of another processor's memory controller quickly. For this to work though, each processor's bank of memory must be configured identically but this is simple enough to do and is well worth it.

We thought the expansion potential of the x3850 X5 was impressive but the RX900 S1 takes this into the stratosphere. Internal design is particularly good giving easy access to all key components. The top panel is split into three sections where the middle one provides quick access to the four hot-swap cooling fans. Underneath the rear panel are all the PCI slots whilst the front panel slips off to reveal the processor/memory riser cards.

Onboard storage is provided by eight SFF (small form factor) hot-swap drive bays. Our review system included four 147GB 6Gbps SAS drives, but Fujitsu also offers SATA and SSD options as well. The drives are linked to an eight-port SAS controller which includes 512MB of cache memory and a battery backup pack. Even better is the fact that it uses its own dedicated slot, leaving all the PCI-Express slots free for use.

There's room for up to sixteen PCI-Express cards – more than double that of the x3850. The PCI-Express slot arrangement comprises a removable vertical carrier to one side at the back with room for up seven low-profile cards. The motherboard offers a further nine PCI-E slots, also half-length, but four of them support hot-plug capabilities.