Video bug lag saccade slow

That media is highly compressed "interframe" long-GOP. In other words, besides the standard "compression", it only records a complete frame to disc every 9-30 frames. In between, it records a data file of the pixels that have changed since the previous (or next) 'I' frame. So the computer de-compresses an I-frame, sends it along for playback & to RAM, calls up the next p or b frame data-set, recalls the I-frame, computes the differences ... sends on & stores ... calls up the next data ... on and on.

Very hard on the hardware to do that and do all the things that a heavy duty video editing program like PrPro demands at the same time.

If you have only the 8 GB of RAM, and only one spinning hard-drive disc ... you've got hardware limitations there also. Not enough RAM for what's needed, and not enough read/write speed to pass all the data to and from the motherboard as needed.

Adding at least one other fast late-generation SSD to either a direct connection with the motherboard, or a Samsung T3 via a USB3 port, and putting your projects and media on that drive, leaving the programs and cache files on the system drive would help.

Also ... at the least, "ingesting" that media using Media Browser's "Ingest" option, set to create proxies using a Cineform preset, would allow it to make media for editing purposes that would pass through the system better. Do NOT confuse smaller file-size on disc with easier playback ... H.264 mp4 and Qt mov files are NOT appropriate codecs for proxies. Cineform, or DNxHD are better.

I know people who use Media Encoder or Prelude to batch-convert such media to files named exactly as the originals, in "full" quality. They archive the originals and use the transcoded files ... typically again Cineform or DNxHD/R ... for editing. When they archive the project, they dump the transcoded media, putting all the project files into the folder tree with the archived original media, as they can make new transcodes for editing if needed ... and the transcoded files are maybe 2-4 times bigger on disc than the original media.

Neil