Quick Summary: A comparison of Sonar and Studio One showed a massive speed difference opening clips in Melodyne (Sonar much slower).  
 
Quick background:  I used Cakewalk/Sonar for many years but switched to Studio One for a while and then returned for X3 and am up-to-date with 2017.10.  Also update to date with Melodyne for this comparison and same for S1 (which I keep for the mastering page and CD burning mostly)
 
I was using S1 when it announced the first pairing of Melodyne and ARA, and though I didn't use it a lot I had some familiarity with the speed of opening clips in Melodyne when I switched back to Sonar.  Over the past year-plus I got the impression Melodyne was slower in Sonar but didn't take the time to check until last night.
 
This comparison used a 7MB, five-minute mp3 file (192kbps) of a commercial track (I'll skip the details for now but in short I wanted to create a live-feel tempo map, which is a really cool thing to do for use with Superior Drummer); when I had tried using a WAV file in Sonar I gave up after 27 minutes of the machine chugging away and the progress circle was barely past halfway.  As my specs show, this is a pretty powerful machine, and if there is a setting somewhere in my machine I'd love to get to the bottom of it, but the S1 stats show that might not be it.
 
Anyway, I converted the WAV to mp3 and used Melodyne in both Polyphonic Sustain and Polyphonic Decay mode.  Here are the average comparison times from multiple tests:
 
Sonar:   Sustain:  Approximately 18:30 to open a five-minute file
             Decay:    Stopped after 19:00 minutes both times
 
S1:        Sustain:  3:00
             Decay:    4:10
 
These figures match the perception that Sonar has always seemed slower at creating Melodyne clips but I'm interested to hear what others have experienced.
 
For what it's worth, Melodyne reached the halfway point in its progress circle rather quickly most of the tests, but then really delayed during the second half, particularly the last quarter.
 
All insights greatly appreciated,
 
Steve

You might want to detail your process for opening the clips and having Melodyne process them within each DAW.
 
For Sonar, there are a few different ways to open/use Melodyne.
 
In terms of creating the tempo map, I'm guessing the way you are using Melodyne in Sonar isn't the most efficient for that particular function.  18 minutes to create a 5 minute tempo map seems pretty high to me.  (though your signature is actually pretty vague in terms of your processor and type of RAM)

I've never used Melodyne with MP3 (didn't know you could). I've also never used S1, so I can't compare that. But it only takes a minute and fifteen seconds to render a five minute and twenty -four second clip (mono clean electric guitar or stereo mixdown, both took the same time) using either polyphonic mode. I used to think that was taking to long.
 
I am using Melodyne Studio in SPlat 2017/10.

I have used this only one time two weeks ago.... I moved 2 notes! I had to step away!
When I came back to my system 5 minutes later, it had crashed!
 
Other then that, it works great with drag audio to midi. :) well a bit (Too many note) messy clean up. but it's still cool!
I haven't tried the drum replacer yet, if that's part of Melodyne... so?

SONAR doesn't read MP3 files directly, it imports and converts everything to WAV files and uses only those.  So I'm not really sure what exactly your MP3 to WAV process actually was.  Perhaps you could give a step by step for both SONAR and Studio One.  Also I'd be interested to know how long the stand alone version of Melodyne takes to do the same operation.  I'd think that is the better comparison.

Right MP3 has nothing to do with the equation. If you import an MP3 into SONAR it is converted to a Wav file.

After 50%, Melodyne start actively write "separations" files.
 
It seems like it always does that, even when RAM is available.
 
The locations of these files defined in Melodyne preferences, "Recording". So make sure:
a) the folder is on fast storage
b) if you have an antivirus or other real-time scanner, exclude that folder and the process from scanning (in this case Sonar).
 
On my system (see signature), there is a huge difference in Melodyne timing between with and without (b).

Good point azslow. For the record there is no interaction between the DAW and Melodyne while it is analyzing data since that task is inside Melodyne not the DAW. If its taking longer in one DAW wrt the other it is likely an environmental issue with how the two DAW's are set up or some dependency you are not seeing.
 
Have or followed up with Celemony to find out why its taking longer? They may be in a better position to answer that question. If there is anything we can do on our end they will certainly contact us...

I work all 4 weeks with Melodyne. Sometimes StandAlone, sometimes as VST-plugin, and I have also testet the ARA integration. But I see no difference in timing between StandAlone, VST or ARA. I use Melodyne Studio. The computer has 3 SSD drives. Opening 5 minutes of a vocal track (polyphon) needs about 2 minutes if its ready to work with.

Numbers for reference, 3min30sec Polyphonic detection:
 
- HDD disk : 4min20sec
- RAM disk : 2min30sec
 
As RAM disk I have used: http://www.ltr-data.se/opencode.html/#ImDisk
 
Since my system is below any reasonable for Sonar+Melodyne, if detection on your system is slower, check my previous post