I have a couple of machines running quad cores, 8GB RAM, RAID. Everything is virtualised. Order entry kept seperate from decision support tools. Everything networked- my own scripts to control input for everything. Multiple datafeeds, multiple data providers. Several screens - two 40's and two smaller (24"). Big screens to run all the charts...smaller for order entry and other control functions. When I did all of this kit I was routinely watching 16 futures markets + extras. (FX crosses, stocks, sectors - depending on what was happening). Everything is VMware sever (windows guests where necessary but on robust linux hosts) and VNC over a fast local net, gigabit switch, redundancy in everything. Custom programmed order entry, different input devices, and scripts to make everything work smoother together. Real geeky stuff. Whole rig takes > 2KW. Not cheap to run. Gets pretty hot as well. Well over $10k worth of kit when it was all bought a few years back. Haven't needed an upgrade, and I now trade in far less markets.
20-foot wide LCD w/ brainwave interface http://www.gizmag.com/fleet-commander-rts-touchscreen-game/19235/picture/137897/ http://www.gizmag.com/goodbye-touchscreen-xwave-brainwave-interface-for-idevices-unveiled/16296/