2 x 24"

However as I simplified my trading strategy to a point where all I really need is one chart, the 2nd monitor mainly serves as excess space for futures.io (formerly BMT), news / movies if market's slow or yet to be opened.

While actually trading, it is (should^^) be turned off.

For other computer related stuff & coding I REALLY REALLY love having two reasonably sized monitors. As for my actual trading they'd be useless if my notebook had a bigger screen. (13" is a bit small, with a 17" one I would most probably be fine, tradingwise... sth for christmas, maybe )

Big Mike 

Please vote and discuss. The question is how many monitors you have connected to your trading system(s).

Cashish 

I have 6 Samsung 23 inch 1920x1080 because, I like BIG charts.

All kidding aside, this is a purpose built system I put together early in 2011. I designed it to run eight monitors from four Nvidia Quadro NVS 295 video cards. This MSI motherboard sports 5 PCI Express slots. At the time of the build I installed 4 Samsung BX2331's I added 2 more soon after. I have had all 8 connected and everything preforms without issue. I've since retired 2 of the 8 monitors to my "internet connected" computer. My eyesight ain't what it was 10 years ago and I've sure enjoyed the charts that often take up an entire 23 inch screen!

I have six Dell S2740L monitors. They are 27" 16:9 ratio (1920 x 1080)

rleplae 

i have 6 monitors (1440 X 2560) connected to my machine, turned vertical i use an AMD firepro W600 special graphics accelerator card with an intel i7 4960 CPU (6 cores) running windows 8.1 64 bit with 32 Gb, corsar DDR3, samsung 256 GB SSD 840 Pro, and 2 X 2 TB hard disks running ninjatrader in 64 bit mode the machine is laser beam fast i rarely see the cpu going over 15% before i had 3 screens on my laptop, and it was swapping like hell, took 2,3,4 seconds to take an order it allows me to follow easily 3 instruments simultaneously i don't trade simultaneously, but i look for entries simultaneously i use audible alerts (synthetic spoken message, to warn me of setup coming near)

Blue Horseshoe loves Anacott Steel.

I use 2x24'' Samsung LCDs @1920x1200 for charting and one 19'' LCD for DOMs only.

Thinking to replace them with new 27'' IPS LCDs @2560x1440