Well, QuickTime is not a codec, it's a wrapper that can contain a lot of different codecs... So is MXF. I assume you mean ProRes when you say QuickTime, and Maybe DNxXD when you say MXF?
I can add that I can do multiple streams of H.264, XDCAM, REDRAW and other codecs and formats without any problems on my HP ZBook 17 laptop. I have 3 SSD drives, 8 GB of Video-RAM and 32 GB RAM, but the processor is just an i7.