Logic Pro X High Disk performance meter


I am mixing my album and I am getting a very unusual high disk performance meter read. We originally recorded this album at a studio that a very early pro tools system. The album was recorded at 16 bit 44.1Khz live to 8 tracks.

I have a 3.4Ghz i7 iMac with a FW800 western digital drive.
I have never experienced such high disk meter read.
Project does not stop playback but Disk Performance meter os always around 80"

Recorded audio files are 16/44.1 aiff files.

any ideas?