Problems with C70 footage in premiere 2023

We are having a lot of problems editing C70 and other misc footage types in Premiere 2023 and I wanted to see if anyone else is having a similar experience.  I mention c70 specifically as this codec performs the worst in all of our test.   I'm hoping to share some test results here to see if anyone else has any ideas. 

Fist, I would like to note that we tested importing files on two different machines.  When I mention PC below I am referring to a i9 13900K 3.0Ghz 24 Core machine with a Nvidia 4080 built by Puget Systems.  For our mac test, we used a M1 Max Mac Studio.  For both of these systems our primary storage is a 10Gbe Network Attatched storage appliance from a very reuptable vendor who is also helping us look into this issue.  For both machines an AJA network speed test is showing around 800MB/s Write Speed and 1100MB/s Read speed connecting to the storage.  Straight file transfers from both machines seem to backup these speeds as we don't have a problem copying footage to or from the storage.  

The problem really only comes in when we are accessing the footage through premiere.  For the test below I imported 10 clips, 2.2Gb of footage total.  I started a stopwatch when I clicked import and then stopped the clock when all 10 were in the bin, loaded and ready to playback.  

On The PC through the network storage this took 24 seconds to complete.  

On the Mac through the network storage this took 1min 54 seconds to complete.  

Just to compare I also moved the same 2.2Gb of footage to the internal SSD of each machine.  I also cleared cache to make sure it wasn't skewing my results.  

On the PC through the SSD this took 2.94 seconds to complete

On the Mac through the SSD this took less than 1 second to complete. 

At first glance this would look like an issue with our network storage however, I think there is a deeper issue here.  For the next test I took the same 10 clips and transcoded them using a non adobe tool (media encoder also takes longer accessing these files) to ProRes 422 files.  This expanded the size of the same clips to 3.8 GB total, almost double the original file sizes.  Then I re-ran the exact same test over the network storage.  The results were in my opinion pretty crazy.

On The PC through the network storage this took 1.65 seconds to complete.  

On the Mac through the network storage this took less than 1 second to complete.

For another interesting stat while testing on the PC I left Task Manager open so that I could see the 10gb network performance.  When loading the prores files the network port stays very active and is pulling down a lot of data.  When importing the C70 files the nework deoesn't pull in near as much data as the c70 does.  The maximum bitrate stays much lower than it should be for importing.

As I mentioned I'm focusing on the C70 as it seems to be the worst, but I do see the same trend on other formats like Canon C300, etc.  Just not quite as drastic as I've seen with the c70.  Also here I'm only focusing on import times as it was easy to standardize on, however we see these same issues when working with the footage in the timeline or even getting thumbnails to be visable in the bin.  For this example I just used 10 clips and a clean premiere project but some of our projects have over a 1000 of these clips so the issues are just compounding and making the entire editing experience miserable.  

In conclusion, is anyone else seeing issues with different codecs?  I'd love to discuss this and troubleshoot with others as I definately to need to get this resolved as transcoding all footage will prove to be quite the undertaking for some of our projects. 

Thanks,

Tim