Why does a fresh restart = higher FPS?

[PkennethV]

I don't really have much a problem with restarting my SSD-equipped iMac, so this question is more of a trivial/wondering why kind of thing…

I haven't been keeping precise logs or anything, but this is my general observation.

Why is it that, after a day's of work on my fully maxed out 2011 iMac 27" (16GB RAM, SSD + HDD, 2GB VRAM, i7), if I simply quit all my open applications and start playing Team Fortress 2 or Left4Dead2, my frame rate is significantly lower than if I were to restart my computer before playing?

Technically, regardless of whatever the computer specs are, shouldn't the performance be the same whether I quit all open apps vs restarting anyways?

 

[Hansr]

Depends on background processes. Quiting open apps ≠ killing all processed launched through a day of usage.

 

[PkennethV]

Depends on background processes. Quiting open apps ≠ killing all processed launched through a day of usage.

I guess I kind of figured that's the answer, so perhaps what I'm really asking then is, since I pretty much only use "reputable" apps (for a lack of a better word) - Aperture, Photoshop CS5, Chrome, Things, Twitter, Notational Velocity, and Apple apps...why, in this day and age, don't those apps do a good job of killing all their process when quit?

 

[Hansr]

If you'd ever worked on a large scale programming project and seen the average skills or junior programmers you'd understand

Might be a good idea to check activity viewer before and after, have a look at the processes and if anything has been paging out.

 

[malman89]

I mean a few of those programs are memory intensive programs. I never check Activity Manager in OSX because I don't game in it really (almost solely in XP via Bootcamp), but I'm sure OSX has some memory leakage throughout opening/closing programs like Windows (though Windows is certainly worse).

After intensive bouts of simultaneously logging multiple accounts of an MMO, many relogs and endless zones; opening Chrome, Firefox or both and tons of tabs opened closed; all while typically running Spotify in the background and sometimes an IRC client and some other things... performance is definitely hit. If I do that consistently I try to restart every 2 days for ideal performance.

Then again, it doesn't happen too often that I spend 2 days straight in XP without restarting, but the rare time I do go into a gaming marathon and have no need to reboot into OSX to simply mess around surfing.

 

[Hansr]

If running only applications you know you can trust not to leak memory it shouldn't be an issue. I'm at around 800MB of page outs after leaving my machine on for a month.

 

[Sackvillenb]

"Reputable" has little to do with the quality of programming. Programs are inefficiently designed sometimes, and humans of course make errors all the time. Photoshop is a great example you've used. It's a very "professional" program, it's been around for ages, and it's very useful to me. But I've always found it to be one of the most unstable programs, for multiple versions. Crashes far more often than it should, especially when you consider the steep price tag.

I reboot relatively often just for the performance boost, especially if I've been using "heavy duty" programs for a while.

In theory, programs should indeed be clearing out their memory use, but reality is not quite so perfect...

 

[Hellhammer]

I would claim that this is more OS X related than app. When you quit an app or process, OS X does not free up the RAM. Instead, it marks it as inactive. Inactive means that there is data from a recent process (to speed up restarting that process in the future), but other apps can now use it in case they need.

The problem is, sometimes OS X doesn't use the inactive RAM but pages out instead. Sometimes I have over 2GB of inactive RAM but my system is paging out like crazy. I would say OS X has issues with inactive RAM in some cases, although it could be app related though (I've mostly used Safari when this happened and it's part of OS X anyway).

 

[viktorcode]

It is a known bug in Lion. It is caused by one of two things: ATI graphics or an older display-related software (like the one creating virtual desktop extension on the display of other Mac).

It is very easy to check if your system is plagued by this issue: check FPS in any game after restart, then put Mac to sleep, wake it up and check FPS again.

There are few discussions going on about it on Apple’s forum. Working but dangerous solution is to install Snow Leopard’s ATI kexts. Personally, I won’t recommend it, but there are few people who got positive results doing so.

In any case FPS drop can’t be caused by memory-intensive tasks you’ve run *before* launching the game, and unless you do video encoding or 3D rendering or similar heavy task alongside the game you won’t see peak FPS drop.