Page in and page outs please clarify

[TopHatPlus]

Hey so i have a 2010 15" MBP 2.66 ghz i7, with 4 GB ddr3 1066 ram, 500 GB 7200 rpm HDD, and the nvidia GT 330 M gpu. I tend to get down around 30 MB of ram when i am running Starcraft 2.

I do not understand what pages in and pages out means. Before i started SC 2 it was like 50k + pages in and 0 pages out. After running SC 2 for like2 hours i have 150k+ pages in and 100k + pages out.

I am pretty sure i just need to add some more ram but i would like to know what these mean so i can better monitor my system.

Thanks

 

[spinnerlys]

Mac OS X: Reading system memory usage in Activity Monitor

Page ins / Page outs

This refers to the amount of information moved between RAM and the hard disk. This number is a cumulative amount of data that Mac OS X has moved between RAM and disk space.

Tip: Page outs occur when your Mac has to write information from RAM to the hard drive (because RAM is full). Adding more RAM may reduce page outs.

Page ins and page outs - could somebody please explain this to me in idiot fashion?

OK, to summarise what it means, your computer has a certain amount of RAM, which is its "memory". It simulates more RAM by allowing extra data to be saved to the hard disk, which is known as Virtual Memory.
To do this, it breaks your memory space up into "pages". Applications that need access to data that is in memory call the data by page. If an application calls a page and it is in the RAM, then it is a "page in" occurs. If an app calls for a page from memory, and that page is currently stored on the hard disk and has to be read back into the RAM, then a "Page Out" occurs.
A "Page-out" slows the operation of the system down because it has to read the data from a hard disk into RAM first, rather than reading straight from the RAM. Hard disks take about 300 times as long to transfer a page of data, which adds up to slow performance.

If page-outs exceed page-ins, you definitely don't have enough RAM. Ideally, page-outs should be less than 20% of the number of page-ins (the fewer page-outs, the faster your machine is performing) On my machine, I aim for less than 5%.

Adding more RAM, or reducing the number of open applications, are the only ways to reduce page-outs. While freeing up memory by working with fewer and smaller files and apps may help, more RAM is the only reasaonable solution.

via "page in page out mac os x"


It means more RAM might be needed, but SC2 is not able to address more, as it is a 32-bit application and thus limited to 2GB of addressable RAM.

 

[TopHatPlus]

thanks for the links?

so if i go from

50 000 in / 0 out

to

150 000 in / 100 000 out when i play SC2

would doubling my ram to 8 GB drastically reduce this number? (the outs)

 

[spinnerlys]

thanks for the links?

so if i go from

50 000 in / 0 out

to

150 000 in / 100 000 out when i play SC2

would doubling my ram to 8 GB drastically reduce this number? (the outs)

I doubt that, as SC2 can't address more than 2GB RAM, as it is a 32-bit application.

Do those page outs worry you or hamper your game play extensively?

My current readings, without playing SC2, but opening Windows via VM and using Avid Media Composer to log footage.

 

[TopHatPlus]