Displaying images on a rasberry pi

I wondered if any uses a raspberry pi to run psychopy experiments, and if they have a work around for a problem I have encountered.

i found installation quite straight forward and as long as millisecond precision was not required experiments that display text, ran fine. However if you display an image there is more than a second delay when registering a key press. I have played around with image sizes and this does effect matters slightly, but the size of the images were not particularly big to start with, its also independent of what image format i use i.e. (png, jpg, bmp). i am using a raspberry pi 3 model B 1Gb ram.

has anyone else found this, and has anyone any ideas of a way around this, as raspberry pi’s offer a great way of collecting data.