I am not referring to multiple monitors in general. I have been doing dual display since my P3 days.
Googled ,
Tomshardware on the Samsung SyncMaster 940ux, another Samsumg LCD USB monitor
For Usb monitors, if the graphics card is not needed, someone has to be involved in processing and support of the monitors, more so with high refresh rates, high res.
" Given the fact that the USB controller requires CPU cycles to work, there is an obvious concerns how much of your CPU this technology will need. Two connected monitors resulted in a 30% load on a single Intel "Core 2" CPU core, or about 8% on a quad-core Core 2 Extreme QX6800 (2.93 GHz). Expect 50% of one Q6600 core being loaded in such a scenario.
If you are looking at a much less powerful CPU, such as AMDs Turion 64 X2 2.0 GHz, the numbers were a total CPU load of 60-70% - or 100% of one core. That leaves you with only 30-40% of your available processing power. So, plan on using such a system with a powerful processor, ideally a high-end quad-core chip. "
For the usual daily less intensive running of softwares / movies / document viewing a USB connection on a lesser CPU is definitely a simpler alternative. as a matter of fact I am looking at multiple LD220 for my dad's nxt trade terminal
Ryan