Howto:Build a cheap FlightGear box
As of 01/2013 you can get refurbished ProLiant DL585 G4 servers for about $200- $300 US on ebay. These come with PCI-express slots (x16) and between 8-32 gb of RAM, 4 dual core processors (opteron, 2.8 ghz, 64bit).
You really don't have to spend necessarily all that much money for a powerful FlightGear capable machine, you can even buy a used machine.
Basically, the only things you really need for running FlightGear is a relatively modern OpenGL graphics card and lots of RAM, preferably with multi core CPUs in the range of 1-2 ghz.
So, one of the easiest and cheapest ways for getting a powerful FlightGear machine (multi core, multi GPU, gigs of RAM) is to simply check out ebay and buy a used and refurbished multi-core server.
You will want to look for a relatively modern server with an x86/x64 architecture (64bit) and multi-core CPUs with >= 1 ghz each.
For example, the DL580 series is pretty powerful, you can get a G3 (3td generation server) with 4 x1-2 ghz CPUs, 8 GB RAM and 250 GB HD for as little as 100 USD now.
If you need something more modern and powerful you can look for a DL580 G4 (4th generation server), these come with 16 x 3.2 ghz (Intel XEON MP, 64 bit, 8MB cache), 4-64 GB RAM and 500 GB HD, for about 150-350 USD - depending on the hardware installed.
Shipping for these machines is usually in the range of 30-60 USD (weight!)
These servers are usually refurbished and come with 12 months warranty.
The major problem when using such a server for running FlightGear is actually getting a decent and modern graphics card for it. While most servers come with built-in onboard graphics, these are of course completely unsuitable for use by FlightGear because they lack good OpenGL support.
This is because most of these refurbished servers predate the "PCI-Express" era.
So most servers will only come with standard 32 bit PCI slots or their 64 bit wide equivalents (PCI-X), more modern servers will at least have an AGP slot.
While AGP cards are no longer being manufactured, it is of course still possible to buy those cards. Depending on your budget that might be a very viable option. Some of the latest AGP cards at the end of the AGP era used to cost $ 500 US or more, that was back when PCI express was just being introduced.
And those cards were really high quality. Certainly more powerful than on board graphics or old PCI based cards.
Now that there is hardly any demand for AGP cards anymore, that means that you can get those cards VERY cheaply. There used to be AGP cards that had 256 MB or even 512 MB of dedicated memory already several years ago, and if you check now ebay, you'll find a bunch of "old high quality AGP cards" that sell for about 15-30 USD now. We are talking here about cards that used to cost a small fortune a couple years ago.
When you do a quick ebay search, it turns out that there are still plenty of AGP cards available, both from nvidia and ATI - even completely new ones, that come with 12 months warranty.
Most of the "high end cards" cost (new!) in between 30-100 USD now, and all of them come with OpenGL 2.0 and shader support. All of the following cards are available as AGP models, and have 512 MB of dedicated RAM:
- GeForce 7600 GT
- GeForce 7800 GS
- GeForce 7900
- GeForce 7950 GT
The GF 7950 GT sells for about 90-100 USD on ebay at the time of writing (10/2010), used models are available for as little as 20-30 USD. Depending on your power supply, you might even need to replace your power unit to cater for such a beast ... (not likely to be a problem in a server though)
Make sure to check if your motherboard can handle such a card, and do check out tomshardware.com
It is only since fairly recently that servers are being equipped with PCI-Express slots, and even then you will not have the full bandwidth - for example the DL580 G4 (4th generation series) only provides PCI-e x4 slots, whereas graphics card will benefit from x16 speed.
There are even OpenGL capable graphics card available that are specifically made for PCI-X, these are usually for CAD applications and used in powerful workstations (like the Wildcat series, with 768-1.5 gb of RAM. However, you will want to ensure that you don't run the original CAD drivers, but just the reference drivers from the chipset manufacturer, because FlightGear simply is no CAD application.
But there are still several "relatively modern" PCI graphics cards available that can be used for running FlightGear. One of such cards is the PNY GeForce 8400GS (512 MB), which can be bought (new) for about 30-50 USD, or for as little as 10-20 USD used: http://www3.pny.com/8400-GS-512MB-PCI-L ... 9C269.aspx
Alternatively, you can look around for servers that provide AGP slots to install one of the more recent AGP cards with 512 MB RAM and shader support. These are now also pretty cheap.
On the other hand, the nice thing about PCI cards is that you can install multiple identical cards in parallel, to make use of multiple GPUs. Unfortunately, the 8400GS series does not support SLI configurations: http://www.nvidia.com/object/geforce_8400_Gs_faq.html But running multiple cards in parallel, does work pretty well.
Another thing worth noting is that most servers that you buy won't have any sound support built-in, but a decent sound card can be obtained for as little as 10-20 USD (check ebay again).
The good thing is that these servers are pretty robust and can be easily used to run multiple instances of FlightGear (or even build it at the same time), on the other hand they are also pretty heavy and noisy, and watch out for the power consumption!
So if you don't mind assembling your own machine, it isn't necessarily all that expensive to get a pretty powerful machine for running FlightGear.