Dell PowerEdge R815 server review

A highly configurable server that will appeal to small businesses

Dell's PowerEdge R815 looks almost identical to the PowerEdge R810 server we reviewed earlier this year, and shares the same 2U chassis as well as many of the options and components.

However, whereas the R810 is Intel Xeon powered, the R815 is designed for AMD chips, with four sockets to take the latest Opteron 6100 series (Magny-Cours) processors.

Released in March 2010, the multi-core Opteron 6100s are the big guns of the AMD processor armoury, sporting either eight or 12 cores.

As such, it's possible to configure the R815 for up to 48-way processing, compared to a mere 32-way on the R810 using Intel's latest Xeon 7500 (Nehalem-EX) chips, currently capable of delivering up to eight cores per socket.

The AMD chips are also available with a lower power envelope than for Intel's Xeon 7500s which, depending on the exact processors used, can make the R815 cheaper to run.

Plus the chips themselves are a lot less expensive, and Dell is marketing the R815 as a "budget" solution for smaller companies wanting to maximise performance without breaking the bank.

Of course, the term 'budget' is relative, and server price will always depend on a lot more than just the processors. There's memory, storage and networking to take into consideration, not to mention additional redundancy and management options.

Indeed, to get the maximum benefit from the R815, most buyers will end up paying a lot more than the £4,469 starting price (ex VAT and shipping) quoted on the Dell web site.

Dell's answer is its FlexMem Bridge technology, implemented in the form of special adapters to fit into the empty processor sockets. These connect, or bridge, the processors in a two-socket setup to the DIMM slots which would otherwise be inaccessible. A single FlexMem bridge can also be specified on a one-processor server, giving it access to 16 memory modules.

FlexMem uses two controllers per processor and doesn't affect memory speed, enabling 2P server buyers to get the benefit of the huge memory scalability on offer without having to pay a premium for processing power that they may not otherwise need.

Actual savings will, of course, depend on the processors involved, but to get an idea we priced a basic R810 with a pair of four-core E6510 processors and came up with a figure of just over £5,300+VAT. The same system fully populated with a set of four-core E7520 processors (the cheapest of the 7500s) worked out at almost half as much again.

FlexMem also allows cheaper memory modules to be used to deliver the same amount of RAM, and the server Dell sent us was a good example. Although fitted with top-of-the-range eight-core Xeon X7560 processors, it had only two onboard, using FlexMem Bridge adapters in the other sockets to enable all 32-DIMM slots to be accessed.

These were then filled with 4GB 1066MHz DDR3 modules (the only specification supported by the new processors), delivering 128GB in total. Using 8GB DIMMs would have made it a lot more expensive, pushing the price well above the £16,000 Dell quoted for this specification.

Our server also came with another Dell innovation in the form of so-called 'fail-safe' virtualisation. In practice this is circuitry to take twin SD cards, thus enabling a second redundant virtualisation hypervisor to be fitted. This is another first for Dell, although it's worth noting that the company officially supports only the VMware hypervisor at present.

Another limitation is the lack of room for storage inside the 2U chassis, which has just six 2.5in drive bays to play with. Still, on our system these were filled with fast 146GB 15K SAS disks linked to a Dell PERC H700 RAID controller. This enabled us to configure a usable, if relatively small, RAID 5 array. Higher capacity drives are available to push maximum internal storage to 3TB.

Solid state drives can also be specified, and there are plenty of expansion slots to take plug-in host bus adapters for external arrays and SAN connectivity. Added to which our server had four integrated Gigabit Ethernet NICs, complete with TCP offload engines for network attachment and iSCSI support.

The new Nehalem EX processors are big on performance and, with two eight-core Xeon 7560 processors and all that RAM, our model was certainly no slouch. It was fairly noisy, with a bank of six hot-swap fans in the centre of the chassis, but power consumption was remarkably frugal and we were very impressed with the build quality and the attention to detail when it came to layout.

No special tools are required for maintenance, as the processors are arranged in a line across the centre of the unit with the DIMM slots in front. Some of these are poked under the storage, but this simply slides out for access. The whole fan assembly can also be removed if needed, and there's good airflow across the whole system.

Redundant power supplies are yet another option, and seem to get smaller and smaller with every new model.

There are several options to choose from on the management front, the review system shipping with Dell's iDRAC 6 Enterprise controller with all the remote management bells and whistles including a dedicated Ethernet interface.

The R810 motherboard includes Dell's Lifecycle Controller, a really useful option complete with its own NVRAM and management console. By doing away with the need for installation media these make server deployment and maintenance a whole lot easier, and we are continually surprised that other vendors haven't done something similar.

It's hard not to be impressed with the PowerEdge R810, and we were certainly knocked out by what the review system had to offer. Prices start at just under £5,000+VAT for a single Xeon 6500, but expect to bump this up considerably by the time you add more options.

A typical configuration like ours will more than triple that figure, and you can easily breach the £20,000 mark by the time you add extra processors, memory and disk space.

That said, the R810 works out cheaper than most of the RISC-based alternatives against which it's pitched, and the FlexMem technology makes it even more affordable for buyers looking for extra RAM but not the expense of a full 4P platform.