The benefit of slightly higher power consumption, in this case, is higher performance. With the Intel Xeon X34xx series one effectively gets Core i7 CPU performance and the ability to use six registered ECC DIMMs (on motherboards that support the feature) in a relatively low power package. The X34xx series has four cores and supports Hyper-Threading with the X3430 being the exception without Hyper-Threading (a great reason to spend a few dollars extra on the X3440). Performance wise, the X34xx series all have WinSAT CPU subscores above 7 and therefore, are suitable for any type of transcoding in WHS V1 or VAIL. My Xeon X3440 and X3460 score 7.4 and 7.5 respectively.
Once one decides they need a high performance chip with ECC memory support and the ability to encode various types of media, the Xeon X34xx series makes a lot of sense. Power consumption is significantly lower than a fairly comparable Core i7 920 or the AMD Phenom II X4 965 Black Edition platform which is often a deciding factor. In fact, I would go as far as to say that most users would be better served by a Xeon X3440 than the upper end of the Clarkdale Core i5 range for home servers, despite the fact that the minimum power consumption that one can achieve is significantly lower on the Clarkdale due to the on-package GPU. On the other hand, the Xeon X34xx series of CPUs is simply excessive for most users in a Windows Home Server.
The LGA1366 Core i7’s and Xeons
My main WHS is powered by a Core i7 920 running on a Supermicro X8ST3-F. With that being said, it is a complete waste for WHS V1 and VAIL to have a CPU based on the LGA 1366 socket, unless you have very specific requirements. My WHS is currently running in Hyper-V with a Windows 2008 Server R2 host operating system. The total running virtual machine count is usually 6-8 making 12GB or more of RAM and LGA1366 sensible. Furthermore, the server has over 60TB installed at any given point so there is an element of scale involved that dictates that specification. Unless your application is similar, this type of setup requires too much power and generates too much heat to be worthwhile. Of the fifty plus custom WHS machines I have built, only myself and two other clients have had requirements that exceeded what a Xeon 34xx series CPU could offer. Simply put, one should know if they need a Core i7 9xx or Xeon W35xx series (essentially a Core i7 with ECC support) and realistically, very few people will need this level of performance from a Windows Home Server.
AMD CPUs
AMD clearly makes compelling parts for home servers. Thus far I have experimented with the Phenom II X2 555, Phenom II X4 955 BE (and through unlocked multipliers the Phenom II X4 965 BE) and the Sempron 140 Sargas and 240 Regor. While AMD is well behind Intel when it comes to the lower-power 32nm process, AMD does have four key features. First, unlike Intel CPUs, most consumer AMD CPUs support ECC memory functions, even on low end CPUs. Second, AMD has segmented the low-end to mid-range market like crazy. It seems like AMD has an offering in the $50-100 space at virtually every $5 increment. One can get 1-4 CPU cores at varying speeds with varying amounts of cache. An accompanying key feature of AMD CPUs is price. AMD’s saturation of the sub-$100 processor market is great for consumers because Intel’s only, and barely, sub $100 offering is currently the Pentium G9650. Finally, AMD allows backward compatibility of Socket AM3 CPUs with DDR2 memory when in a Socket AM2 platform. For the average user, this can mean $100 saved on 4GB of memory for the home server.
The two main negatives of the AMD platform are stock power consumption and the fact that most AMD motherboards do not come with Intel Gigabit NICs onboard. Power consumption is a derivative of the AMD’s failure to integrate ATI GPUs on die/ package (which Intel has done across multiple lines already) and the fact that AMD is still on a 45nm production process. AMD systems still require an IGP or discreet GPU unlike the Pineview and Clarkdale chips, and that generally requires additional power consumption. Cool’n'Quiet can only do so much and my results with undervolting, while generally good, do vary a lot from CPU to CPU making it hard to compare an undervolted AMD platform to a stock Intel platform.
On the subject of component limitations, while the traditional whitebox server motherboard manufacturers such as Supermicro and Tyan cater to the LGA1156 and LGA1366 platforms, their offerings generally are limited to AMD’s server sockets such as the G34 that are incompatible with Socket AM3 CPUs. Therefore, most companies making AMD motherboards for consumer CPUs are consumer oriented and therefore lack IPMI remote management/ monitoring and Intel gigabit NICs (which are widely regarded as superior to Realtek NICs common on consumer boards). One can easily add Intel NICs to AMD systems, but this adds to system power consumption and cost of the server. For users that do not want these features, AMD makes a very strong value proposition due to highly competitive pricing.
Conclusion
The biggest piece of advice I can give in CPU selection is to both temper a desire to go overboard and at the same time, do not skimp on a CPU (or motherboard) purchase. Realistically, very few users will need the LGA1366 CPUs and they frankly consume too much power to make candidates for both WHS V1 and VAIL. On the other hand, users building upon an Atom based platform or low-end Sempron/ Regor AMD platform may run into performance issues transcoding video and/or with system expandability. The key is finding the CPU and platform that allows for the best combination of power consumption, performance, expandability and price. Hopefully this quick guide provided you with a framework for CPU and platform selection looking forward to VAIL. The CPU marketplace is constantly changing and a few months from now Sandy Bridge may well make all of the above CPUs all but irrelevant.
Thanks to Patrick for a great post – let’s hear your thoughts on the processors you have selected or are thinking of selecting for Vail, and once again, follow Patrick’s continuing adventures in self-builds over at Serve the Home.
