Will Moutain Lion fix my lag?

So here is the situation: I'm testing FCP X 10.08 on a fully featured Mac Pro with double screens and broadcast monitor. The test footage is Prores 422, coming from network storage and the event and project are located on an external disk (as I can't save then on the server...).

If I (try) to edit with the broadcast monitor on, it takes about a sec before he starts playing (every time). The same with going to double speed etc. When turning off the monitor, it goes fluently.

Now, the OSX is 10.7.5 and I've been told by another editor that FCP X does not have those problems when using OS X 10.8. But before I do a clean install of 10.8 (and by that also disabling a much used FCP 7 plugin, that's no longer supported in 10., I'm looking for some confirmation on this.

Will Mountain Lion fix my lag?


Thanks

The first question I guess is how is to getting to broadcast monitor? AJA? Black Magic?

Blackmagic

Hmmm. Well I'm running a black magic card hooked up to an ancient MacPro with two 24" Monitors so I don't even have the option to go to Mountain Lion and while I do see a little bit of lag it's certainly nothing like a second.

I do prefer to edit with it off though as any lag in playback drives me up the wall. I also switch it off when using AVID or FCP 7.