#1520 Performance difference depending on screen font

[Michel Ricart]

Apparently, the CPU usage greatly depends on the selected screen font: I use ProFont, and iTerm uses between 30 and 50% of the CPU. When selecting Monaco, it drops down to 9%. I get this with recent (0.9.6.20090923) and less recent (April) releases, but only recently. I'm running 10.5.8, so it could be an interaction with something in this OS release. Apple Term works fine.

[James Bunton]

Thanks. What hardware are you using? Does this happen with any other fonts? I don't have ProFont on my computer to test with unfortunately.

[Kim Nørgaard]

I am experiencing the same thing, using: PanicSans 12 or Share-TechMono 12.

[Michel Ricart]

Thanks for taking care. I am using a PowerBook 2GHz Core 2 Duo, 3GB memory (667MHz DDR2). ProFont is free and available here: http://www.tobias-jung.de/seekingprofont/. Let me know if you want me to seek for other problematic fonts.

[James Bunton]

I cannot reproduce this with the current SVN. I tried ProFont and ProFont IsoLatin on my Powerbook G4. Opening Vim or paging through a manpage doesn't seem to use up more CPU than with other fonts.

[Michel Ricart]

Do you want me to look for other fonts causing the same behavior?

[James Bunton]

Yeah, that may help. So it definitely happens with 0.9.6.20090927 then?

[Jeremy Hinegardner]

I am on Snow Leopard and am using http://www.ms-studio.com/FontSales/anonymouspro.html AnonymousPro font and I saw this on builds from 20090920 up through 20090923. I could switch between Monaco and AnonymousPro and watch the CPU go up while just sitting in vim on a file if I was on AnonymousPro, and then switch to Monaco and the cpu would drop immediately.

This happend on my iMac5,1 and my MacBookPro4,1

I just tried 20090927 and the problem appears to be fixed. If I encounter it again, I'll post here.

[Michel Ricart]

I'm using 0.9.6.20090923, not 0.9.6.20090927 - where can I find 0.9.6.20090927 ?

[James Bunton]

Version 0.9.6.20090923 and 0.9.6.20090927 are broken and will not auto update to future releases. You can fix this simply by ticking and unticking the "Prompt for test release updates" box in preferences. Alternatively, download a newer version directly http://iterm.sf.net

[Michel Ricart]

I am now running 0.9.6.20090928 (note, I could not find those test-release built on http://iterm.sf.net\) and get the same performance differences. The easiest way to show it is by running e.g. "top -ocpu -Otime -F", and playing live with the font selection. I will check for other fonts tomorrow (sorry, to busy today). Michel.

[Kim Nørgaard]

I use a third generation macbook pro and I am still having the same problems with 0.9.6.20090928. When running top and playing around with fonts I have noticed that basically any other fixed width font than courier and monaco results in around 17-19% cpu utilization while those two results in 3-4% cpu utilization. It doesn't matter what size I use or if I use anti aliasing.

[James Bunton]

I still can't reproduce this. Can somebody please try this:
* Close iTerm
* Move ~/Library/Preferences/net.sourceforge.iTerm.plist somewhere else (eg Desktop)
* Start iTerm and change the font
This way I can tell if it happens with the default settings. If not, then it's a matter of figuring out what the culprit is. You can of course move your original prefs file back afterward.

Thanks.

[Michel Ricart]

Just did what you suggest, and I get the same. More precisely:
- 80x24 screen: Monaco 12: 5%, Monaco 9: 5%, ProFont 12: 10%, ProFont 9: 11%
- 135x60 screen: Monaco 12: 7%, Monaco 9: 5%, ProFont 12: 22%, ProFont 9: 23%

From this fresh state, I made other tests with a ~135x60 screen:
- Those fonts are ok: Courrier, Courrier New, Helvetica, Helvetica Neue, Lucida Grande, Times, Times New Roman.
- Most of the other fonts show the problem, in particular (i.e. highest CPU load): Futura Medium, Geneva, and the worst I could find is Microsoft Sans Serif, using 35% CPU

Hope this helps.

[James Bunton]

Older versions of iTerm (prior to 2009-03-13) cached the results of font rendering. There were various issues with this, so I removed it. At the time I tested with a variety of fonts to ensure rendering speed was about the same. Could somebody please check to see if there is any difference in performance with the older versions of iTerm that used the character cache?
The changelog on the downloads page shows the dates that things were modified.

[Michel Ricart]

Hi James, I have just tested iTerm 0.9.6 and as far as I can tell it doesn't show the problem, so you likely found the cause of the problem. Thanks again for taking care. Michel.

[Anonymous]

This is also fixed in iTerm2 at http://code.google.com/p/iterm2/

[Michel Ricart]

Yes, iTerm2 is fine. Weird that I was not aware of this iTerm2 release.