RAM and Mavericks?

alwayslikethis wrote:

My question is, how much RAM is Mavericks supposed to use itself? I just installed Mavericks and, upon starting up my computer, close to 5GB of my RAM was being used. I have a total of 8GB RAM, on a late-2012 21" iMac. I find this to be odd because on Mountion Lion only about 2.5GB would be used once I booted into my computer.

This is my computer as soon as it boots up, with no programs open:

Is that to be expected from Mavericks?

It's a tough call but from what I have seen and read OS X Mavericks handles memory much more differently than any other version of OS X released before. I too see higher memory consumption in Mavericks on my 2010 MacBook Pro with 4GB of RAM but the computer does not feel any different in terms of responsiveness to OS X Mountain Lion. My take is that now the important measurement in Activity Monitor that the user needs to watch while using their Macs is the Memory Pressure chart, that I think will go higher as the system memory becomes more stressed.

According to the keynote by Apple today the amount of memory used by OS X Mavericks does not matter as much because if the OS is in a situation where RAM is running low, Mavericks will compress the memory from the unused apps to give the needy app the necessary memory and with no user interaction.

Hope this clarifies and you can learn more about OS X Mavericks new features here:

http://www.apple.com/osx/whats-new/#advanced-tech

dont judge ANYTHING immediately after install of a new OS.

Wait till you reboot / restart to judge anything in RAM use.

Your Mac may be re-indexing, it's very memory intensive. Check your Spotlight icon.

Mavericks' new memory compression algorithm will enable better use of whatever RAM you have.

You may see all 8 GB used, but it will start to become "compressed" as more is required. According to today's presentation this "compression factor" can be significant, allowing you to utilize as much as 50% more RAM than would otherwise be available before resorting to the swapfile. For those of us accustomed to traditional resource allocation, such a claim is akin to Apple repealing the law of gravity.

The effect will be to prolong the useful life of older or more resource-limited Macs, as well as reducing the power consumption of portables.

More is explained here: http://arstechnica.com/apple/2013/10/os-x-10-9/17/

"Mavericks doesn't even touch swap until it's squeezed several gigabytes more data into RAM than the Mountain Lion system."

In a theoretical sense any unused RAM is being wasted. A well-designed OS should use ALL the RAM ALL the time. It's only if an application can't do what it needs to do or performance suffers that there's a problem.

So... you're saying that with NO apps running AT ALL.... My Mini should use ALL 16 gigs of RAM I have JUST for the OS?

Sorry, I have to call "BS" on that one.

C F McBlob wrote:

So... you're saying that with NO apps running AT ALL.... My Mini should use ALL 16 gigs of RAM I have JUST for the OS?

That's not what I meant at all. Note the word "theoretical". And when I wrote "A well-designed OS should use ALL the RAM" I did not mean "JUST for the OS". Beyond that, a freshly-booted OS won't have anything (other than itself) to load into RAM, so there's not going to be much to occupy it.

I am getting the same problem. I use a vm to run linux os, since I upgraded to 8GB of ram, I have had no problem until I upgrade to the new OS X Mavericks. It is now making everything slow, and my mac pro is making some noise. I was running 10.6.7 version prior to my upgrade.

Like everyone else, I was expecting even better memory usage.

I also find it annoying that you have to press arrow the down key before the scroll bar appears on any page where you need scrolling

Segzy wrote:

It is now making everything slow, and my mac pro is making some noise.

In that Activity Monitor display, select the CPU category and click on the CPU column to sort by descending CPU use. What do you see at the top of the list?

Mavericks, as with all versions of Mac OS X will dynamically assign memory as needed. The Unix memory model is very different from Windows, or Mac OS 9 which preceded it. The real problem with memory is how much does your third party application play nicely with accessing hard disk, memory, and graphics chip for its needs. Some programs have more of a memory leak than others. If you use iCloud, or Bonjour, you'll see a lot more background resident memory in use than if you don't. The real question becomes how much do you really need to be there. And keeping your hard disk from overflowing is still important since once it exceeds 85% capacity, memory swapping takes place a lot more frequently and can slow matters down.

System Preferences - General - Check the box in Show Scroll Bars that says always. :-)

C F McBlob wrote:

So... you're saying that with NO apps running AT ALL.... My Mini should use ALL 16 gigs of RAM I have JUST for the OS?

Sorry, I have to call "BS" on that one.

Here's the thing. I do not think it is worth worrying about any amount of RAM usage as long as your Swap Used is 0 bytes. As long as that is the case, that means OS X is using as much RAM as it can to cache data to make things as fast as possible. Some applications pre-cache, meaning they set aside RAM in anticipation, for performance reasons, before you've even done much.

If you keep opening more apps and Swap Used is 0 bytes, that means OS X is intelligently turning over RAM to new apps, or employing RAM compression in Mavericks, and that means there is no penalty of any kind for using up most of your RAM.

I would only become worried if Swap Used starts to pile up early and continually. That means you just don't have enough RAM for what you are doing.

My Vm is taking the most cpu & memory as I suspected

thanks mate - it was set to always by default before the upgrade, I thought it would be the same after upgrade. if I ran into any more issues, I will first check my system settings before posting about it. Thanks🙂