A lot of attention should be focused on the hardware assembly. There are many tradeoffs and considerations of speed bottlenecks. You should be careful to settle on a vendor with experience, where they can give you good recommendations.
Here is a list of hardware, which we assembled at the artificial olfaction lab at the Institute for Bioengineering of Catalonia. Prices are as of May 2008 and do not include taxes.
We bought 8 computers with these parameters:
- Intel Core 2 Duo Quad Q6600 2.4 GHz FSB1066 8MB
- Chipset Intel X38 / Intel ICH9R
- 4 GB RAM DDR3 1066 (in 2x2Gb).
- 2 x PCI Express x16, 1 x PCI Express x1, 2 x PCI-X y 1 PCI
- Marvell88E8056 Dual Gigabit LAN controller
- Realtek ALC882M 7.1 chanels (sound
- 6 USB 2.0 ports y 1 IEEE1394
- VGA 512MB Gforce8400GS PCI-e
- 160 GB de Disco Duro SATA II 3 Gb.
- DVD R/W, Multicard reader/writer
- 19" rack computer case, 4U, with frontal lock.
- 550W Server Guru
They cost 923 euros each.
In order to operate 8 computers efficiently you need a monitor that you can connect to all machines. Better even a KVM (keyboard video mouse). A KVM with 8 ports cost us 850 euros. The KVM, as the name says, serves as keyboard, monitor, and mouse, and did great service during configuration because it allows fast switching between different computers.
We also need to connect all the computers among themselves: A switch with 16 ports, 10/100/1000, comes at 162 euros.
We want to put all the hardware somewhere, where it is save and where it has good conditions of cooling and safety: a rack (see picture). The rack on the picture can take up 42 units of 19 and cost us 500 euros.
Don't be surprised to be charged extra for cables, screws, and multi-outlet power strips. Rails allow you to stack in and take out your computers like drawers. Additional cost: about 700 euros.
Also on top, the VAT, in Spain 18%, which makes about 1500 euros.
Total cost of the beowulf: about 11,090 euros.
In order to connect your computers, you need power lines that can support them. The configuration above needs about 4.5kWatt and we had to wait about 2 months for technicians to fix the capacity (that's Spain).
On the photo you can see the computer hardware mounted into the rack. You can see the 8 computers flanking from two sides the KVM which is in the middle, behind it the switch.
Beginner's Experiment ClusterEdit
This cluster may not be the fastest one out there, but it is small and cheap enough to build and operate by a single beginner:
Bill of material for one single node:
- System board: Raspberry Pi 2 Model B. This cost $35. This single board computer packs a quad-core ARM Cortex-A7 processor at 900MHz frequency, a GPU capable of 24GFLOPS if used as GPGPU, and networking with an onboard USB to 100BASE-TX adapter. Mounting holes on the board allow you to design mechanical structure for the final system easily using standard mounting hardware.
- Memory card: Any class 10 microSDHC card with at least 2GB capacity will work. At least one seller sell reasonably good class 10 4GB microSDHC at $5.
- Power supply: A reasonably good one is available on Amazon for about $10.
This means about $50 per node. Other housekeeping parts includes an ethernet switch (about $50 for a 8-port one) This means an investment of $400 you can get a 7-node cluster to experiment with.