So I have a gtx 1060 a i7-4790 and 16gb ram and I am having problems with the playback on the video its so laggy and when I try to do the shift+b thing it stops half way through please help
Shift+B will only buffer as many seconds as can fit in the ram preview buffer size. It stops when the buffer is full or your entire selection has benn buffered. Whichever comes first. The ram preview setting is in your preferences.
The preview window size setting will greatly affect the number of seconds you can buffer with ram preview. e.g. Half will buffer four times and many seconds as Full will. If you preview window is at Auto it might already be in Half or Quarter depending on the size of your preview window. The status info listed at the bottom of the preview window will let you know this if you are interested.