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10th December 2011, 12:09 PM |#6695  
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Memory and SuperCharging Overview or... "Why 'Free RAM' Is NOT Wasted RAM!"
Originally Posted by androidusero1p500

@zepp, when I go to app management and see free ram it shows 190-200 though almost no apps are running and usually it shows 320-330..
Is this what you say to be cached n helps in making things snappy?

Sent from my LG-P500 using Tapatalk

Actually I explained it a couple of pages ago.
See the MFK Calculator Info post where I discuss that a bit.

cat /proc/memfree
The cached data is "invisible" to most free ram monitors in that it is included in the reported free ram.

This is why you always hear "free ram is wasted ram blah blah blah"

I'm thinkin no ram is really wasted.
I don't think I'm a linux guru as I've never ran a linux pc.

But I've read enough that I can make sense of the numbers and their effect.

Seriously, if free ram is wasted ram then the phone would never slow down when low on ram and it wouldn't get snapply after killing a bunch of apps.

This proves that the "free ram" is actually "doing something" and if it's doing "something," then it's not really wasted, is it?

Sorry gurus, but that "wasted ram" mantra makes zero sense.

The trick is to find the free ram level (includng cache) where things start to slow down.
Anything above that won't bring any benefit and needlessly detracts from multitasking.

Edit: Wow I just found a great overview which says that I'm right on the money! lol

Linux Memory Consumption

...the kernel tries to utilize the most of the RAM to improve the system performance. Keeping the cache means that if the kernel or a task needs the same data again, there’s a good chance it will still be in the fast cache in memory.


This is what I've been using to determine slot 3

...wants to know actually is the minimum amount of memory that the system requires in order to function properly. Let’s call this number “The absolute free memory number”.

AFM (absolute free memory number) is what I've been calling the "lag level" where things slow down below it and anything above it brings no benefit.

Wait... there's more...

The absolute free memory number ("lag level") is...the sum of the MemFree, Buffers and Cached fields.



It means that the majority of the used memory by Buffers and Cached (ie. AFM) can be reclaimed in case a task will require it, while reducing the amount of buffers and cached. Using unused (clean) cache will not impact the system performance. However, degradation in the system performance will appear once starting to free used cache (ie. AFM goes down).

Booya! (Bonus: Details on the "Engine Flush" LOL)
Basically all of it says what I've always said - but in geek speak...

To summarize: Performance degradation occurs when AFM decreases.

Which is fancy talk for: "Lag happens when free ram goes below the 'lag level'"

So yeah... next time a guru says "free ram is wasted ram," the reply is: "Define 'free ram'."
Because if they mean free ram as reported by most apps (ie. MemFree + Buffers + Cached), they are 100% wrong.
Last edited by zeppelinrox; 24th January 2012 at 01:01 AM.
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