FCP X: Avoid Lion Slowdowns
Recently, I’ve gotten reports of sluggish FCP X behavior in Lion. William Hohauser sent this in, which I found so helpful, I wanted to share it with you.
While the newest update to FCPX has improved the program and eliminated several bugs, at least for me, it has introduced a new issue that was not there before. This is on my 2009 8-core MacPro with an ATI Radeon HD 5870 1024 MB video card and 16gb of system RAM.
Since the introduction of Lion I have had Mail and Safari enabled to be full screen apps where I can use a four finger swipe to access. Since the new update I noticed that FCPX would slow down especially during exports when I would swipe to the Mail program or Safari. In fact the whole computer would visually freeze up at times although the export was still going. Switching between applications was slow and could take a while before the next program actually appeared on the screen.
Activity Monitor did not show anything out of the ordinary so I downloaded the program atMonitor to monitor the video card. What I saw was that full-screen apps can absorb up to 70% of the VRAM even though you are not on the particular program. This was clearly conflicting with FCPX and slowing things down. Once I stopped using full-screen app function on the program, FCPX exports are back to normal and I still have both Mail and Safari open. In fact I just was exporting with FCPX and writing part of this while keeping an eye on the VRAM stats. With FCPX open and exporting the VRAM hovered around 70% used. With the export finished I quit FCPX and the VRAM dropped to 10% with Mail and Safari open. Before, with full screen apps activated, the VRAM stayed at 70% regardless of whether FCPX was open or not.
Larry replies: Thanks, William, for writing this up.