[hyperasus]

Ok so here I am crusing along at the end of a long day when suddenly vista tells me the Vista Aero theme has is being set back to Vista Basic because it is using up too much memory. Given I am multi tasking like a mad man, but I also have tons of system memory. I'm not noticing any kind of delays or performance lags. I see no reason why Vista should be gimping me back to the ugly Vista Basic look. Is there a setting somewhere or some way to make so Vista can't disable the Aero look just because I'm using more memory then it thinks is ok?

Some screenshots of my task manager.


sorted by memory usage.


I realize that this could be fixed with a reboot. But whats the point of having all this power and memory if I can't do everything at once? I have 5GB of RAM in my pc, according to task manager I am only using 2.9GB at the moment. So way is Vista complaining to me?

[redduc900]

You might want to try Vista's built-in Help and Support if you haven't already... Start | "Help and Support" | Type AERO in the Search box, and hit ENTER | Click on "Troubleshoot problems with Windows Aero".

[hyperasus]

Oh you mean actually do some research. And here I was wanting to be lazy LOL. I"ll give it a try and see what I can come up with.

[Captain Newbie]

Holy buffalo crap, look at all the processes.

I think this is a bug; those guys don't look like they're releasing their resources properly, creating a memory leak.

Nothing in the knowledge base; please contact Microsoft Product Support Services.

<end unhelpful>

[aaronjb]

I don't think this is a bug, but related to how windows allocated memory to individual programs, and how windows makes use of the page file. Remember that memory is allocated in pages, and even though an application may be using 100MB of memory, the footprint in pages is most likely greater.

Look no further than your free physical memory and unused pages. You've triggered a kick down to the normal Vista theme from Aero due to a lack of available physical memory. At this point, new pages will have to be swapped in from disk, and unused pages swapped out, with the algorithm deciding what stays in physical memory vs. what's swapped out to disk.

With Vista's "Superfetching" (nothing new here, this is probably a variant of the Least Recently Used algorithm with a preference bit added), preference is given to pages which are most frequently swapped out. Over time, this means that applications which require new pages more often than others are granted more pages in physical memory and less swapping. Because Aero dynamically calculates translucency and window resizes, etc, it's given a larger chunk of physical memory than applications which are more static, or work on data in the background, etc. Latency is key with a window manager, so frequent swaps to disk to do that kind of work is a no-no.

Summary: Vista is saying "Hey, Aero is using too much main memory, and your apps need it. Aero runs too slow when it has to page to disk all the time, so we're shutting it down."

[deathman20]

I've used way more memory then that and haven't had Aero shut down. I've used up to 3.6Gig of ram but less processes.
.
Interesting thought if it is shutting down because its slowing down.

[aaronjb]

Originally Posted by deathman20

I've used way more memory then that and haven't had Aero shut down. I've used up to 3.6Gig of ram but less processes.

That's the key. Fewer processes, fewer applications competing for preference in the paging algorithm. Also, memory is allocated more efficiently with fewer total processes.

HyperASUS: The JavaVM is notorious for taking memory and never giving it back.

[Captain Newbie]

Originally Posted by aaronjb

I don't think this is a bug, but related to how windows allocated memory to individual programs, and how windows makes use of the page file. Remember that memory is allocated in pages, and even though an application may be using 100MB of memory, the footprint in pages is most likely greater.

Look no further than your free physical memory and unused pages. You've triggered a kick down to the normal Vista theme from Aero due to a lack of available physical memory. At this point, new pages will have to be swapped in from disk, and unused pages swapped out, with the algorithm deciding what stays in physical memory vs. what's swapped out to disk.

With Vista's "Superfetching" (nothing new here, this is probably a variant of the Least Recently Used algorithm with a preference bit added), preference is given to pages which are most frequently swapped out. Over time, this means that applications which require new pages more often than others are granted more pages in physical memory and less swapping. Because Aero dynamically calculates translucency and window resizes, etc, it's given a larger chunk of physical memory than applications which are more static, or work on data in the background, etc. Latency is key with a window manager, so frequent swaps to disk to do that kind of work is a no-no.

Summary: Vista is saying "Hey, Aero is using too much main memory, and your apps need it. Aero runs too slow when it has to page to disk all the time, so we're shutting it down."

Yeah, but the WM is used by all user-land programs...and should probably stay in memory. Especially if you have 5GB of it, which is a ridiculous amount, but that's a topic for another day.

This is a bug, or an unintended misfeature--you should not shut down the WM when you have 5GB of physical RAM, of which, over half is unallocated.

Does this happen when you have an 'even' quantity of RAM (say, 4GB)?

(In fact, with the abundance of relatively slow but cheap and abundant physical disk, combined with intelligent paging, there's simply no excuse these days for running out of physical memory unless you are running a HONKING big application, but that's another topic for another thread.)

[aaronjb]

Originally Posted by Captain Newbie

Yeah, but the WM is used by all user-land programs...and should probably stay in memory. Especially if you have 5GB of it, which is a ridiculous amount, but that's a topic for another day.

It's not shutting down the WM - only scaling back to the basic WM, which uses less memory. Vista considers the WM to be less of a priority than applications and other processes.

Originally Posted by Captain Newbie

This is a bug, or an unintended misfeature--you should not shut down the WM when you have 5GB of physical RAM, of which, over half is unallocated.

It's not a bug, but a conscious decision made by the developers. Vista aggressively caches memory to reduce paging. That's why so little "free" RAM is shown in the screenshots. For a brief technical look at Vista memory management compared with XP, check out this tidbit. SuperFetch is explained in more detail there.

I agree, however - the user should be able to force aero on, no matter the potential performance hit.

Also, I believe that you can turn SuperFetch off, to give you more free physical memory. This will come at the expense of overall system performance, but you may not reach the "limit" at which Vista sees fit to shut down aero.