See 2nd post on this thread to see if any of that helps.

As time goes by, Windows gets clogged with this and that. One more program with its hidden overheads gets added to another, and so on. Uninstall doesn't do a complete uninstall.

I do a system backup after a clean install of Windows and must-have apps. Then, when Windows seems tired, I go back to this backup and add the nice-to-have apps, and I have what seems like a new computer.

Make a list of tweaks and settings for your apps so these can be quickly restored after re-installation.

Don't forget to save any data on your C: drive before doing a restore. (Do a full system backup before you start as insurance!) As much as possible, data should only be kept on non-system drives or partitions.

I just put my system spec on there 2 weeks ago, and now there is nothing. I'll add them again. But I'll add it here as well.
(edit: I hadn't selected "Display system information on my forum profile page" when I last updated it)

Vegas 12
AMD FX-9370 8-core
16.0GB Dual-Channel DDR3 @ 803MHz
AMD Radeon R9 270X Graphics (2GB)

My computer is less than a month old, with an SSD for the OS and programs, and internal hard drive and externals via USB 3.0 for footage, so it should be speedy enough and not bogged down too much.

I always have the project properties match the files imported. Like I said, the original AVCHD files play without a single hiccup, at Best/Full and at 60P. When I first got this new computer, I was curious if I could do that. But when I make a MXF or XDCAM file as a master, they are stuttering no matter what the preview quality is set to.

I love that my system plays so nicely with AVCHD, but it's odd that the files you'd expect to play back smoothly, don't.

I'll get it figured out. It's probably one silly little thing I've overlooking.

are all files playing from the same harddrive?

+ 1 donaldt.

i'm no expert but i've found playing files from some external devices (hd, cards, etc.,) can sometimes prove problematic.

for editing, etc., i always work from an internal hd (ditto - os + progs on ssd plus 2 internal hds for bouncing project renders etc).

With this particular project, all files, AVCHD and the rendered MXF and XDCAM are all on the same internal hard drive.

I just finished the project I was working on and burned the DVD's and Blu-rays. Now that it's out of the way, I'll spend today going over things. I'm sure I've missed a setting here or there.

I work with high bitrate MXF files a lot - 50Mb/s. The computer is clearly working harder to pull in these files than an "ordinary" AVCHD file. For example, rendering to AC3 is much slower from the MXFs than AVCHD files.

Thanks dxdy. How do they play on your system? With mine, it's not bad stuttering. Just enough to irritate me.

Have you updated any drivers recently? I recently updated my video card driver, and that update lead to all kinds of playback (and rendering) hiccups. Went back to old driver, and all is well again.

I'll check into it, Ken.

@DGates

They play fine with the Sony XDCAM player. Not so well with VLC or WMP. This is on my i7 5960 with AMD R9 290X.

They preview fine in SVP 13 even with 3 or 4 FX applied (Color corrector, unsharp max, etc.). However, with PIP, 2 MXFs on screen at once, preview stutters.