New RAM usage

GGJstudios

macrumors Westmere
May 16, 2008
44,419
759
Is this a normal situation the uptime is around 3 and 1/2 days no shutdown only sleep.

Running Programs:

Parallels Desktop 7: 4GB Windows 7 Pro
iTunes
Safari
Mail
Calendar

Thanks just Curious :p
No page outs, so you're not maxing out your RAM. As to what usage is normal, that depends on what you're running at any given point in time.
 

Intell

macrumors P6
Jan 24, 2010
18,883
372
Inside
Completely and utterly normal. Mac OS X, as with most UNIX based operating systems, free ram is wasted ram.
 

DWS1187

macrumors newbie
Original poster
Nov 15, 2011
17
0
Kinston, NC
Thanks. I am loving the 16GB. Just installed it a week ago. Running parallels windows 7 with 4GB of RAM is much better, before I had 8GB and it ran okay, but I was running around 7.8+ used with iTunes, Safari, Mail, Messages, Calendar, and Parallels Desktop 7 open and I didn't like that so I upgraded.:D

On another note, does OS X use the RAM it's given? In other words will it efficiently use the RAM according to the total installed? I have witnessed Windows 7 using 800MB of RAM with 2GB installed and nearly double when using 4 GB of RAM on a desktop. I find this intriguing...almost like the computer doesn't care as much to conserve when it knows it has the RAM. Thanks again.:apple:
 

stevelam

macrumors 65816
Nov 4, 2010
1,215
3
Thanks. I am loving the 16GB. Just installed it a week ago. Running parallels windows 7 with 4GB of RAM is much better, before I had 8GB and it ran okay, but I was running around 7.8+ used with iTunes, Safari, Mail, Messages, Calendar, and Parallels Desktop 7 open and I didn't like that so I upgraded.:D

On another note, does OS X use the RAM it's given? In other words will it efficiently use the RAM according to the total installed? I have witnessed Windows 7 using 800MB of RAM with 2GB installed and nearly double when using 4 GB of RAM on a desktop. I find this intriguing...almost like the computer doesn't care as much to conserve when it knows it has the RAM. Thanks again.:apple:
of course it'll use the ram its given. whats the point if it couldn't? same with windows. fyi, assigning more cores to parallels is much more of a performance gain than going from 2gb to 4gb of ram. obviously this will also gimp your osx side.
 

nontroppo

macrumors 6502
Mar 11, 2009
430
21
I find this intriguing...almost like the computer doesn't care as much to conserve when it knows it has the RAM. Thanks again.:apple:
That is exactly what you want an optimised VM system to do. The same software will show very different memory footprints dependant on how much free+inactive RAM is available. Opera for example can go from <100MB to >700MB with the same pages depending on what you run it on.
 

DWS1187

macrumors newbie
Original poster
Nov 15, 2011
17
0
Kinston, NC
of course it'll use the ram its given. whats the point if it couldn't? same with windows. fyi, assigning more cores to parallels is much more of a performance gain than going from 2gb to 4gb of ram. obviously this will also gimp your osx side.
I am using 2 cores of my i7 processor to run the Virtual Machine, do you think that's enough? Other that the fans running a 4000 to 6000 RPM while using a processor intensive program and the CPU on iStat reporting at or near 70something degrees Celsius, everything seems to operate well.

Opera for example can go from <100MB to >700MB with the same pages depending on what you run it on.
So OS X will vary the RAM usage according to available RAM (makes sense), and is there a technical name of this RAM allocation process?

I feel like i am full of questions today...

oh and simsaladimbamba thanks for the link.
 

nontroppo

macrumors 6502
Mar 11, 2009
430
21
So OS X will vary the RAM usage according to available RAM (makes sense), and is there a technical name of this RAM allocation process?
It is so fundamental I think this is really just "memory management", free pages are allocated on request and the kernel will manage pages based on the number of free pages left, you can read much more detail here:

https://developer.apple.com/library/mac/#documentation/Performance/Conceptual/ManagingMemory/Articles/AboutMemory.html
http://en.wikipedia.org/wiki/Page_replacement_algorithm

And for a simpler version, aimed at Linux but just as applicable to OS X (replace the term "used" with "inactive", another slight wrinkle is OS X uses a unified buffer cache)

http://www.linuxatemyram.com/index.html
 

DWS1187

macrumors newbie
Original poster
Nov 15, 2011
17
0
Kinston, NC
nontroppo, thank you for the wealth of information. I love reading about things such as this. It answers my question perfectly.