I have been test driving a number of trading apps on a Mac Pro/Parallels/XP setup. I find running a single app with an iQfeed runs very well. However, when I attempt to run TWS to feed Button Trader, and the Quote tracker running off iQfeed, it does not take long for something to go wrong and the data stream becomes sporatic, slows to a creep or a complete reboot of parallels/XP is required. Trying to mix Ninja Trader for charting with Button Trader/TWS is even worse. Overall, NinjaTrader seems to be more flakey in the Mac environment than on one of my PCs, easily locking up all by itself. I have also tried Sierra Charts in the mix. just incase QT was sucking up too much processing juice. I'm running on a mac pro with 16GB of ram, manually giving 10GB to Parallels. I'd love to hear any comments regarding a better solution than Parallels, or what can be done to help several apps remain solid with the iQfeed data stream.