Now that Windows 2008 RC0 is released, it's time to start experimenting with Viridian, the new hypervisor based virtual server component of Windows 2008.
Viridian requires a CPU with hardware virtualisation support, so this means it was time to replace my old revision B based Opteron server with something new. I never really succeeded in making my old Opteron server quiet (mainly because the rev. B CPU's don't support Cool&Quiet power management, which results in relatively high power consumption). My PC's are all located in my main office room, so they absolutely need to be quiet in order to maintain a productive working environment. Because of all the noise it makes, the dual Opteron server was only used for beta testing, benchmarking and load testing purposes and remained switched off for most of the time.
So the main requirement for the new server would be to be as quiet as possible, certainly quiet enough not to disturbe the working environment in my office. In the past, I've experimented a lot with making my machines as quiet as possible, and learned the hard way that it isn't really possible to make a quiet PC that consumes a lot of power, not even with the use of sound dampening materials nor advanced fan control. I ended up with a quest for the components that would deliver the lowest possible power consumption at idle (since the server will be idle 95% of the time, if not more), while at the same time provide high performance.
As a secondary requirement, the system should be reasonably fast and support multiple concurrent virtual machines easily.
How low is low enough? Well, my dual Opteron server consumes between 150W and 200W idle. This is clearly a range that is impossible to cool silently (Please note that 'silent' means something different for different people. In my case, it means 'really' silent) with conventional means, that is, without resorting to water cooling or specialty cases like Zalman's Totally No Noise cases. My 'always on' machine, an aging AMD Athlon64 3200 machine consumes between 60 Watt and 70 Watt. This is low enough to be practically noiseless if all power management features are switched on and a silent CPU cooler is used. So the target is 60 Watt, preferably less, certainly not signicantly more.
After a lot of review reading and power consumption comparisons, I came up with the following shopping list:
- 4x 2 GB DIMMs of 667 MHz DDR2 RAM: I chose 667 MHz RAM instead of the faster 800 MHz RAM. In practice, the speed difference is not that big, but the power consumption difference may be significant. Using 2GB DIMMs instead of 1GB DIMMs also results in some power saving, since higher density chips with lower power consumption per bit are used. Since regular motherboards only come with 4 DIMM sockets, I need 2GB DIMMs to get at 8GB anyway.
- 65 nm 2.6 GHz AMD Athlon X2 processor: This is currently the fastest 65nm generation AMD processor, with very low power consumption. This revision also has the hardware virtualisation extensions required by Viridian. I also considered using an Intel Core 2 processor, but the idle system power consumption would probably be noticably higher.
- Abit AN-M2 micro ATX motherboard, based on an NVidia 7025 IGP. Integrated graphics because the server will practically never be used interactively, so the extra power consumption of a dedicated video card can be eliminated. I also considered using an AMD 690G motherboard, but Abit doesn't make such a board. I wanted an Abit motherboard because of the fan control (FanEQ) features integrated into the BIOS. If the fan control is integrated in the BIOS, it will work no matter what beta OS I'm using. In the past I've had the experience that non-BIOS based fan control most likely won't work on beta or exotic operating systems, so I wanted to avoid that. And external fan control systems use wires with temperature sensors, which results in a cable mess inside the computer case. Compared to other vendors, Abit's FanEQ has the advantage that each fan can be individually configured to work against a user selectable temperature probe, e.g. the speed of the case fan can be controlled based on the CPU temperature.
- Antec P182 case: Is there any other case for silence freaks? I used the previous generation P180 for a previous PC and it is easily the best case for building a silent PC. I like the ruggedness of the side panels, eliminating any internal vibration, the case holes in the top to aid cooling by natural convection and the location of the power supply in a separate thermal compartiment of the case. The P182 has some minor improvements to the P180. I remove all the 12 cm TriCool fans and replace them with a single 800 rpm Scythe 12cm fan on the back panel. I leave the opening in the top of the case open for natural convection.
- Scythe Infinity cooler: I used to be a fan of the Zalman CNPS coolers, but don't like their proprietory fans. They are not the most silent fans to begin with, and after some time they start to emit more noise. Since the fans are proprietory, they can't be replaced with a better fan. Scythe on the other hand has a couple of extremely good (but gigantic!) coolers, using standard 12 cm fans. I bought a Scythe Ninja, but it didn't fit on the AN-M2 motherboard, because of the heat pipes extending over the DIMM area. Luckily I had a somewhat similar Scythe Infinity (a leftover from a previous PC build, it didn't fit on a Abit AB9-Pro board, and I had to use a Scythe Ninja instead!) that did fit nicely on the motherboard. I use the Infinity fanless.
- Seagate 160GB 7200 rpm notebook drive: Notebook drives consume a lot less than desktop drives: typically 2 Watt compared to 10 Watt for a desktop drive. This drive is intended as 'always on' drive. Windows can be configured to shut down hard drives after a certain time of inactivity but the boot drive always seems to have a bit of activitity, so it never shuts down. By using a notebook drive as boot drive I can let the more noisy drives shut down when they're not in use. Now that notebook drives also have a standard SATA data and power cable, they can easily be used as a replacement for a desktop drive without having to use those hard-to-find PATA notebook-to-desktop adapters.
- Western Digital 10000 rpm 150GB SATA disk: Western Digital is still the only hard disk manufacturer producing 10000 rpm desktop drives. Despite the high performance, it is one of the quieter desktop drives. I still put them in a noise eliminating hard disk cooler though, just to be sure. I'll use this drive for anything that needs a high number of disk IO's, like database files and virtual machine images.
- Western Digital 750 GB GreenPower SATA hard disk: This is Western Digital's new eco-friendly hard disk. It adapts its speed between 5400 rpm and 7200 rpm depending on hard disk use, and has some other tweaks to lower power consumption. Idle power consumption is about 5 Watt, compared to 10 Watt for a regular drive.
- Seasonic S12II 380 Watt power supply: the S12II range is the new high efficiency (>80%) power supply range of Seasonic. Seasonic has a reputation for building silent power supplies, but I was a bit disappointement by the (little) amount of noise it still makes. My other PC's use semi-fanless power supplies from Nesteq, or specialty low noise power supplies, and they are audibly quieter than the Seasonic. 380 Watt is far more than what this PC will consume.
I installed Windows 2008 RC0 on this machine. I configured the power management settings to shutdown idle hard disks after a couple of minutes. I get the following power consumption numbers (measured with a no-name power consumption measurement tool at the wall socket):
- 80-90 Watt when using 1 CPU at around 100%.
- 53 Watt idle, but with all hard disks active.
- 35 Watt idle, with all drives except the notebook drive inactive.
The 35 Watt idle is far beyond what I hoped for this build. I run the Scythe Infinity cooler fanless. The single 12cm case cooler, which is only a couple of centimeters away from the CPU cooler is configured via FanEQ to shutdown when the CPU temperature is low enough. Most of the time, this is the case and the case fan doesn't spin. The only airflow in the case comes from the fan of the Seasonic power supply at the bottom of the case, and from natural convection through the fan grille at the top of the case. So indeed, it is possible to build a quiet, low power and still high performance virtual server.