Problems with videos lagging

Hello,

I have a MacBookPro and for some time now I've been having problems viewing and editing videos on my computer. I can't watch videos that were taken with my phone and transfered to my computer without them lagging. I also can't use Final Cut or iMovie properly because videos are lagging all the time. I can watch videos on youtube without problems..

Yesterday I've tried to erase and reinstall OS X but it didn't help.

I did some research but I haven't yet found a solution.

Here are my Mac's details:
OS X Yosemite, 10.10.3
Macbook Pro, 15 inch, mid 2010
Model Identifier: MacBookPro6,2
Processor Name: Intel Core i7
Processor Speed: 2,66 GHz
Number of Processors: 1
Total Number of Cores: 2
L2 Cache (per Core): 256 KB
L3 Cache: 4 MB
Memory: 8 GB 1067 MHz DDR3
Processor Interconnect Speed: 4.8 GT/s

I am happy to give more information if it is needed.

Thank you for any help I don't know what else I can do.

How much free space is on the hard drive/SSD? Are other functions slowing down as well?

Hey,

Thanks for your reply!

There is 84 GB free, out of 120 GB, because I've moved everything to my external disk.

Other applications such as iTunes or Photoshop are working fine, maybe a bit slower than a few years back, but I think that can be expected.

Are the videos stored on that external drive? If so, and if you are on a USB2 port, it might be the port speed. You can test by moving one that ALWAYS lags from the external to the internal and see if it lags when played from the internal drive.

Hey,
No, they are on my internal drive (dropbox). I've checked if there is any difference if the video is on the external drive but it's the same with Quick time player. With VLC they seem to work ok, but there is still a problem with iMovie or other video editing programs.

Thanks!

Hello again,

I took my computer to the service company to get it fixed. At first they told me everything is ok and wanted only to reinstall everything (which I've done before), after a couple of days they told me the problem is in the logic board and suggested a new one which would cost me 600€.

I didn't want to go into that expense and was meanwhile trying to find my own solution. I found out that a certain app may help with this problem, so I took the computer back from the service and tried it. I'm happy to say that it helps! My videos are no longer lagging and I can also use iMovie without problems.

If anyone has a similar problem, this is the app that helped me: gfxCardStatus