Servers and desktop PCs used to be hard to tell apart, but that's no longer the case — as is clear when you discover what goes into the making of a modern rack-mount server like Dell's new PowerEdge R810.
Dell's PowerEdge R810 squeezes up to four processors into a 2U rack enclosure
At first glance the R810 doesn't look that different from previous 2U PowerEdge rack-mount servers — or, indeed, similar servers from other leading vendors. It's extremely well made, with power supplied by a pair of redundant hot-swap supplies and an easy slide-off cover that removes completely for access. Inside, however, lurks a superb design that makes for a highly scalable platform which, when properly configured, will rival the processing capabilities of mid-range RISC-based alternatives.
Our review unit had two 8-core Xeon X7560 processors and 128GB of RAM (32x4GB DDR3 DIMMs)
The processor sockets are what you notice first. Sat in a line right across the middle, there are four of them — two more than is usual on a 2U platform. Furthermore, the sockets are designed to take Intel latest Nehalem EX processors, released onto the market at the end of March, which can have up to 8 cores and be deployed in both dual- and multi-processor configurations.
A variety of different chips are available to go in the R810 sockets, from either Xeon 6500 or 7500 families with a choice of 4, 6 or 8 cores, plus multi-threading and, on some, Turbo Boost technologies.
There are a few limitations, of course, such as the ability to specify just two of the cheaper Xeon 6500 processors. Our review unit came with top-of-the-range 8-core Xeon X7560 silicon, although it, too, only had two CPUs. A little disappointing, but it did help to highlight Dell's unique FlexMem Bridge technology, which enables maximum use to be made of server RAM.
FlexMem addresses one of the issues inherent in Intel's Quick Path Interconnect (QPI) technology, which by incorporating memory access controllers into the processor eliminates the bottleneck of the old frontside bus. Unfortunately, if only one or two sockets are occupied you can't, as a result, access all the available memory. So on our R810, for example, we would, in theory be limited to using just sixteen of the available 32 DIMM slots.
The FlexMem Bridge neatly solves this problem by means of a processor-sized bit of circuitry designed to sit in the empty sockets and bridge the otherwise inaccessible memory slots to those that are occupied. Our review unit had two FlexMem Bridge adapters, so Dell was able to supply us with 128GB on 32 4GB DDR3 DIMMs (much cheaper than high-capacity modules); on a single-processor setup, a single FlexMem adapter would allow the CPU to connect to 16 memory modules.
Memory speed is unaffected, and as well as allowing cheaper memory to be used, FlexMem gives R810 buyers access to a maximum of 512GB of RAM without having to shell out for a full complement of processors. This is an important consideration if you don't need the extra CPU horsepower, as those extra processors can add thousands of pounds to the bill.
On the storage front the R810 is a lot better equipped than most desktops, although the 2U format does limit what can be installed. There are just six 2.5in. drive bays, which limits the maximum internal capacity to 3TB.
Our review unit had a relatively modest complement of six 146GB 15,000rpm SAS disks, albeit cabled to a high-end PERC H700 RAID controller with battery-backed cache. Fortunately for customers looking to support large disk arrays, there are also six PCIe slots, making it easy to adds extra host bus adapters and cards for Fibre Channel or IP SAN attachment, as well as four Gigabit NICs with TOE (TCP Offload Engine: Wikipedia) support already built onto the motherboard.
For management, the PowerEdge is equipped with the (still) unique Lifecycle Controller. An amazingly useful option, this does away with the need for separate installation media and lets you run configuration tools from a pre-OS environment. You can then choose from three remote management options, the review system shipping with the full iDRAC 6 Enterprise adapter with remote console, on-board vFlash storage and an independent Ethernet management port. A web-based interface makes this easy to use, with plenty of tools on offer including some to monitor, budget and cap power usage.
The PowerEdge R810 comes with two SD card slots, providing failover capacity for the integrated virtualisation hypervisor
There's another extra on the R810 in the form of a second bootable SD card slot. Dell was one of the first vendors to build an embedded virtualisation hypervisor into its server, and the second SD slot provides additional redundancy for customers looking to run hundreds of VMs on the R810 platform.
Overall, the PowerEdge R810 is about as far removed from a desktop PC as it's possible to get, and we were very impressed with how it performed. We were also impressed by what the server had to offer inside its compact 2U chassis: the four processor sockets and 32 DIMM slots make for a highly scalable platform that can be put to many uses from high-performance computing to web, database and virtualisation applications. The FlexMem Bridge technology also helps here, enabling buyers to take full advantage of the huge amount of memory that can be crammed inside without having to waste cash on superfluous CPU power.
Of course, all this doesn't come cheap: our review system sells for just over £16,000 (ex. VAT), and 4P configurations easily cross the £20,000 mark. But you do get a lot of server for that money, with huge savings to be had from the consolidation possibilities it opens up, making the PowerEdge R810 excellent value for money despite the high purchase cost.