Your graphics engine affects performance, too.

You have not given enough info for me to have a clue.

Okay then. Graphics card is a GeForce GTX 750 Ti (2GB GDDR5).

I'm flying blind here too--what other info would be helpful?

I could go into detail about the particular project, but both projects I have created of about this length experienced the exact same problems:

1) Severe lag in simple entry, which is all I use. (Not really interested in other methods.)

2) Incorrect selection of measures toward the end of a 1000+ measure score.

I realize that second one is difficult to describe, so I'll give a specific example. If I want to switch my bottom staff to treble clef in measure 1014, I right click on the appropriate measure with the clef tool, select the treble clef, and when I click OK, or Done or whatever, the treble clef appears in measure 1016. This effect is more pronounced the longer the score gets. It makes it impossible to do mid-measure clef changes because the selection tool defaults to whole measures as a side effect of this problem.

Point being I'm hoping that improving my hardware will make these problems managable since MakeMusic has acknowledged there is an issue and the problems themselves won't be going away anytime soon (or so I gather from the tone of the post on the subject).

Thoughts?

… If I want to switch my bottom staff to treble clef in measure 1014, I right click on the appropriate measure with the clef tool, select the treble clef, and when I click OK, or Done or whatever, the treble clef appears in measure 1016. This effect is more pronounced the longer the score gets …

I suspect that there is a simple fix for this issue:

Preferences > View > Measure Numbers > Display Actual Measure Numbers

Your problem appears when {Display Defined Measure Numbers} is chosen.

Choose {Display Actual Measure Numbers}, and you are “back in business”.

Do not worry! This setting for Measure Numbers is a program setting (not a document setting).

The setting does not affect the layout, only the display in dialog boxes.

(The problem appears where there are measures with the Measure Attributes setting {Include in Measure Numbering} de-selected)

Are you editing in page view or scroll view?

Score I am editing is over 1700 measures, around 50 staves. I use Speedy Entry, so cannot speak to your Simple Entry woes. I haven't run into your incorrect measure selection issue (although I have run into some other weird stuff). However our machines are probably not a fair comparison (64 GB RAM, 12 cores... but don't worry – that would be overkill if it was just for Finale. It's a sequencing machine, too).