[Valloric]

Originally Posted by DanielCoffey

Oddly enough, another smaller epub I have does it too, but to a much lesser degree.

So what you're saying is that you have epubs for which this doesn't happen? Then attach the epub for which it does so I can take a look at what's going on.

Originally Posted by DanielCoffey

When opening War For The Oaks (368Kb), Sigil's CPU usage goes to 100% and its memory jumps from 25Mb used to 45Mb used then CPU usage settles at 0% once epub is loaded.

This is normal if it takes a few seconds. The loading is CPU intensive because of tidyLib which reads in your HTML and rewrites it completely.

Originally Posted by DanielCoffey

When entering carriage returns in the middle of a paragraph, CPU usage is about 25% but when deleting them, CPU usage hits 90-100% and it takes around 1s per deletion.

On my machine (Core 2 Duo, 4GB RAM), so far I have yet to see an editing task take more than 5% of CPU. But I've tried deleting paragraphs as you've noted, and this does seem to jump the usage to 100% for God knows what reason... but only on HUGE, 50k XHTML lines-of-code files. It's 2% CPU and instant response for average novel-length files (on my machine).

When editing huge files, there's going to be some unavoidable slowdown for Book View. It's still an embedded webkit-based browser.

Originally Posted by DanielCoffey

I then closed Sigil and reopened it before loading the 1.4Mb Deed of Paksenarrion epub. Activity monitor settled at 100% CPU usage and quickly reported Sigil (Not Responding) and memory usage climbed rapidly to 112.5Mb used. Once the epub was loaded, CPU settled back to 0%.

I am not sure if that degree of memory and CPU usage is what you would expect.

As I've said, loading is intensive. There's probably room for optimization there.

Even for huge files, memory usage should remain well below 100MB, between 40 and 70 MB. The Peak Memory Set has for me gone beyond 100MB (102MB actually), but that's for a split second during loading. It always goes down afterwards.

As reported, Sigil should be able to handle very large files even on weak hardware.

This is all on Windows though. I haven't had the chance to do performance testing for Macs much. From my limited testing with an old Macbook, it seems fine though.

But 90-second loading and several-second lag for typing? That should never happen. Attach that epub so I can take a look at it. If you're worried about your file being made available on the internet, just add the "Private" label to the issue which makes it visible only to the issue reporter (you) and the project developers (me).

Without the epub files in question I can only guess. If you provide me with it, and the same slowdown happens on my system, then I can tell you what the problem is (and hopefully I can fix it). If it doesn't happen on my system with the same file, then it must be your system that's at fault.