Recently I experimented with setting up 24-inch 16:9 ratio monitors in a portrait orientation (instead of the default landscape orientation) to view my TradeStation charts. I observed something very strange happened. I have a box with an Intel i7-930 class of processor (pretty good computation power usually) and it drives only 3 monitors (1920x1080 resolution). I installed Windows 7 fresh on it. Then proceeded to rotating each monitor 90-degree (in Windows, adjust screen resolution, in Win7 there is an option to set up monitor as "Landscape" or "Portrait" orientation). Problem came after the portrait orientation was designated. Everything in Windows seemed much slower. Rebooting Windows took much longer. I proceeded to installing TradeStation 8.7 on the box. I used it to display some charts with indicators that I developed. These are the same indicators that I had been using with no problem for months and months. Just that this time the charts were plotted on monitors that are set up vertically. Next day the problem started to show. During market hours... the box was constantly at about 70% to 80% CPU busy - almost on all the 4 cores. TradeStation could not catch up with the chart update (about 5 to 10 minutes behind - those were 1-minute charts). Windows could not track my mouse movement: when I moved my mouse across the screen, it moved 2 inches, stopped (for about 5 to 10 seconds), then moved another 2 inches again, and so on. Tried to right-click on a TradeStation chart to format an indicator - the system did not respond AT ALL! Nothing. Obviously this was not a usable configuration. I decided to re-establish my base-line. On this box: yesterday re-installed Windows 7 (64-bt) fresh. Kept the monitor set at Landscape orientation. Re-installed TradeStation 8.7. Re-compiled all indicators from source codes (in the event of any corrupted TS files). Re-defined all the charts in a landscape screen space. Today was my test during live market conditions. As I expected/hoped, everything was back to normal. The TS charts were updating tick for tick without delay. Per Task Manager, the CPU was only about 5% to 10% busy most of the time throughout the day (yesterday it was 60%-80% busy throughout the day). The difference is night-and-day. I have a theory that Windows (Win7) is having issues with the portrait orientation. While the graphics work, there are extra computations (perhaps very inefficient) to support it. Every graphic entity (points, dots, lines, etc.) would need to be extra-mapped for the portrait orientation. And so with tracking the pointer. So the Windows kernel was busy most of the time. I don't know how realistic my problem theory is. But the performance issue I experienced is very real. Because of that, with regret and disappointment I need to stay with the landscape orientation for all my monitors. I am wondering if any of you are using "portrait" orientation on your monitors in Windows 7. Did you experience any performance problem (similar to what was described above) with your charts? I would imagine the issue is not specific to TradeStation charting but any kind of graphics application.