iMac 5k Retina - Preview fullscreen looks horrible
I was about to buy the iMac 5k retina and was just checking online for the problems that affect it. After reading a few problems regarding the Mission Control Lag, Bluetooth devices not working after wake up etc. I decided to do a test run in the shop before I pull the trigger. I could not do a sleep/wake test but I did the Mission Control lag test by opening about 10 applications and using Mission control. It indeed does feel a little laggy but not to a point that it is unusable. However, I did another simple test - Opening a large JPG file in Preview and making it fullscreen (no other applications were open just Preview and Finder). And this made me not buy it.
While the animation for fullscreen was going on, there were some random colors (purple and blue) on the image. The transition from Preview window to fullscreen felt really choppy and every time I did it, during the process, it looked like the JPG was corrupt with purple/blue blocks and lines on the image. Once it was fullscreen the image displayed fine but during the process it looked horrible.
I did the same test in my Macbook Pro - Mid 2010 with only Intel HD Graphics enabled (NVIDIA GeForce GT330M was disabled) and it does a similar thing but it is not as bad as the iMac 5k. Here is a video of my Macbook Pro Preview Fullscreen test - https://vid.me/QtnE
I am sorry, I did not record a video of the iMac 5k in the shop. Both machines are running OS X was Yosemite 10.10.3
I understand the 5K display itself takes quite a bit of power from the AMD Radeon M290X GPU but going fullscreen should not consume too much GPU power. Can anybody with the iMac 5K retina repeat the same test and share the experience please.
I am just wondering if the iMac 5k is just a beauty only without the brains type of product. Looks good but doing even a simple task that requires a bit of GPU power will overload it. I want to buy it but this kind of thing is holding me back. I have chatted with Apple Support and they said the technical team is notified of this. I hope Apple fixes this in the next software update (or maybe El Capitan).
Looking for answers.
iMac with Retina 5K display, OS X Yosemite (10.10.3)