Thread Ripper Stutter Playback

Hello everyone.  This is my first post so I hope I do it correctly.  I've just finished building system that I HOPED would give me many years of smooth editing.  Sadly I am not having that kind of luck.  Two problems of note:

Welcome screen sits upon launch for up to 20 -30 seconds before plug ins load.  Once they start, the program is up 2 seconds later.

As noted in the title playback is very stuttering.  Regardless of workspace, or resolution (turning it down to 1/4 still results in jittery playback)

Here are the specs on my system and file.. Any help in this process would be wonderful:

Computer and Premiere Data Sheet:

This is a newly built system.  Bacially, Windows 10, drivers, and Premiere.

Premiere Pro CC 2017 11.1.2

Processor  AMD Ryzen Threadripper 1950X 16-Core Processor, 3400 Mhz, 16 Core(s), 32 Logical Processor(s)

BIOS Mode  UEFI

Installed Physical Memory (RAM)  64.0 GB

Name  NVIDIA GeForce GTX 1080 Ti

C drvie is a 500gb 980 Pro onboard SSD (1700 MB/s write / 2555 MB/s Read)

D drvie (Cache drive) is the same. (Same Speed as C drive)

Project is on a 4 drive RAID consisting of SSDs. 

(Write 1269 MB/s / Read 1436 MB/s

File being played back:

Type: MXF

File Size: 12.71 GB

Image Size: 1920 x 1080

Frame Rate: 59.94

Source Audio Format: 48000 Hz - 24 bit - 4 channels

Project Audio Format: 48000 Hz - 32 bit floating point - 4 channels

Total Duration: 00;35;34;38

Pixel Aspect Ratio: 1.0

MXF File details:

Wrapper type: MXF OP1a (type: SingleItem SinglePackage MultiTrack Stream Internal)

File generated by: Sony, Mem  (2.00)

AVC Long GOP High 4:2:2 Profile 10-bit Unconstrained Coding

Bitstream Format: Sony

Class 50

During playback 30% of the CPU is being used.

Aprox 8 MB/s on the hard drvie.

I will be very grateful for any help I can get reaching the editing promised land of smooth playback!

Jay