SOLVED Dorico is incredibly sluggish

I try to work with a piano piece of about 600 measures. It´s the Diabelli variation by Beethoven. Dorico is not able to work with this file. It takes about 4 minutes just to load it. Every operation like starting playback or jumping around in the score is so sluggish that you can drink a cup of tea in the meantime. Isn´t Dorico able to manage a piano score with 600 measures ? I can´t believe it.

That’s not at all typical.

How many cores are you running on your computer?

This wouldn’t happen to be the same file you posted about earlier, which was failing to import from XML? That very well may be related.

I have four cores on a Mac OSX 10.13.6 with 8GB ram. Indeed it is the same file, which I have divided in two parts and managed to load one part into Dorico, which took a long, long time. But now it´s imported and it´s a dorico-file, which causes the issues.

I’m sure that must be related. Dorico slows down a little when you starting working with very large projects and multiple flows, but nothing like you’re describing.

I’m sorry to say that although you did manage to import the XML, something in the file is likely amiss. Just a hunch.

Would you like to post your file here in a forum? So other users could test it as well.

Is Dorico capable for utilising multicore process?

Yes, and cores tend to be the best measure of performance for users.

Mipi, you can find the file in the dropbox- link in my first post.
Dankreider, of course it can be related to the xml-import-issue. But that´s no explanation for this behaviour. All what is in the file , is accepted and created by Dorico. So, what shall be wrong with ths file?


  • those applications have an option to utilise CPU, but Dorico seems not to have the option.
  • those applications show the CPU peak over 100%, but the CPU peak of Dorico does not exceed 100%.

On my MBP (15" 2018), it is very slow.

I had a problem like this earlier. Try unplugging any external midi controllers and see if that fixes it. Sometimes Dorico gets hung up on constant midi messages being sent.

The problem is that the repeat structure in your score isn’t set up to play back properly. Each variation doesn’t begin with a “start repeat” barline, so the repeat in every variation is jumping back to somewhere earlier in the score.

I guess it takes a long time to load because Dorico is initializing the playback data for all the incorrect repeats.

If you go to Play mode (which takes a long time) and switch off “play repeats” in Playback Options and save the score, it then loads in the amount of time I would expect.

Alternatively, if you want to play the repeats, add “start repeat” barlines everywhere they are needed.

Another way to fix the problem would be to make each variation a separate flow. Then the score will play back correctly without adding “start repeat” barlines.

EDIT: Rob beat me to it

Did you read my reply where I mentioned what I thought the problem is with the file? (the repeat structure - specifically the missing start repeat barlines).

Dorico can make use of multiple cores, but only for certain operations that can be done in parallel. If you load a large orchestral score and watch the CPU meter then you’ll see all cores in use during parts of the loading process. However, there’s also a lot of the processing which has to be serial, and in this particular case, the (incorrect) repeat structure takes a very long time to calculate. I would suggest turning off the playback of repeats, fix the barlines and then turn playback back on again.

Thanks for your help. I have done, what you (PaulWalsmley) have adviced to me and the problem is solved. Dorico is now working like it should.
But, I´m still wondering, why Dorico is struggling with the missing repeat- barlines in this way that nothing is working anymore.

Because it’s trying to calculate the repeat structure, and since it can’t make sense of it, it’s going round and round the infinite repeat structure until it gives up. Because it’s impossible in the general case to differentiate between an infinite repeat and an intentionally very long one, there’s not a great deal we can do. It’s very important that you make the repeat structure consistent and clear, not only for Dorico’s sake but also for the sake of your human performers. If Dorico is confused by the repeat structure, your players will be too.

Wibem’s file has the same notation for the repeat structure as the original first edition, but that was formatted into separate “flows” and is therefore quite clear. It would play back OK in Dorico if it was split into flows the same way, of course. Disclaimer - IMSLP: Free Sheet Music PDF Download