Adding more RAM increase PC performance?

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compcons

Platinum Member
Oct 22, 2004
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1,158
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I am Currently using 2.79 GB of 12. I have Chrome and Task Manager open. This is actually a pretty light-weight machine for me without a bunch of crap running. Built for gaming. I have no concern about what is chewing up so much memory, but seriosusly, WTF?!?! I could almost convince myself to start slimming running processes but its too much work and I have some Torch Light 2 to play.

To the more important question: Why 12 GB of RAM? because I can. If I had open slots, I would max it out at 32GB. I just can't justify pulling out the 2 GB sticks or opening the case up...
 

sub.mesa

Senior member
Feb 16, 2010
611
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Well, I never heard a girl or woman talk about 386DX before, so I am pleasantly surprised as well. ;-)

Still, may I add that most people may not be aware that most of your RAM is used as filecache, instead of usage of applications?

As stated earlier by someone else, most applications are still 32-bit even on 64-bit Windows, and thus have a generic 2GiB memory limit per process. This does not mean they can not use more data. You can have a game using 30 gigabytes of game data, but the process never exceeds 2GiB of RAM. For the remaining data, if it has been read earlier it may still be in RAM memory. This is called filecache

taskmanagerexplained.png


Please analyse this image carefully, and let me comment on several important data:

Used memory (Red) indicates memory in use by Windows or applications. This is memory you really need. With less RAM available than this amount, you need to swap to a pagefile which acts as emergency RAM memory that resides on the harddrive.

Look at how low the used memory is compared to available memory. You would assume that you have plenty memory seeing the used memory so low, right? Well actually, the system in this screenshot is out of memory!

Cached (Orange) is where the magic lies. This is filecache. Everything Windows or your applications read from your harddrive will remain in RAM memory unless the memory is needed for other tasks. This means that as soon as you open some applications or start some games, you will build up filecache that can grow to many gigabytes. Potentially as much as data you read from the harddrive.

Available (green) is basically Cached and Free combined. This is the amount of RAM memory that is available to applications. It includes all the filecache because filecaches can be discarded at any moment, freeing that RAM space up for use by applications. But before this happens, unused (free) memory will be utilised first, so that it does not kill the cache whenever possible.

Free (purple) is unused and wasted memory. This number can only be high if you did not yet start enough applications that allow to build up filecache. Or, you just closed a game and this suddenly meant there is room for additional filecache. The lower Free is, the better. However, a really low number like 0 means that you are OUT of memory. This means the filecache can not grow larger. If applications need more memory, they will eat up the filecache.

What is this filecache about?
The whole idea, of course, is that reading data from RAM is much faster than reading from harddrive. You can test this yourself: reboot your computer and start your firefox webbrowser or other application. Now exit the application, wait awhile allowing the system to cool down, then start the application again. You will find that the second time is much faster than the first. This is solely due to filecache; you read from RAM memory the second time, instead of your harddrive.

How much RAM do you need?
My own recommendation is that used memory should never be higher than 20% of total memory. This leaves about 4/5th of your RAM as filecache which is extremely important and useful. I recommend either 2x8GiB = 16GiB memory or 4x8GiB = 32GiB for desktop systems at this time. Memory is cheap, and useful!

However, laptop users who frequently reboot their system will find filecache to be much less useful since it 'resets' every time you reboot or shutdown. Hibernation, however, does retain the RAM filecache so is a suitable alternative. However, it can take awhile to write out 32GiB to disk making shutdown/boot time pretty long.
 

VirtualLarry

No Lifer
Aug 25, 2001
56,409
10,086
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Hibernation, however, does retain the RAM filecache so is a suitable alternative.
I find this to be a peculiar design decision by MS. And a mostly wrong one too. Before putting the OS into a quiescent state, it should flush both the disk write and read caches. Because otherwise, you will run into filesystem corruption, should the filesystem be modified by an "external" OS (think dual-boot with Linux), and then the Windows OS un-hibernated with stale filesystem cache blocks, that then get written out.
 

jaqie

Platinum Member
Apr 6, 2008
2,472
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Well, I never heard a girl or woman talk about 386DX before, so I am pleasantly surprised as well. ;-)
Thanks! :cool: I think? ;)

What is this filecache about?
The whole idea, of course, is that reading data from RAM is much faster than reading from harddrive. You can test this yourself: reboot your computer and start your firefox webbrowser or other application. Now exit the application, wait awhile allowing the system to cool down, then start the application again. You will find that the second time is much faster than the first. This is solely due to filecache; you read from RAM memory the second time, instead of your harddrive.

How much RAM do you need?
My own recommendation is that used memory should never be higher than 20% of total memory. This leaves about 4/5th of your RAM as filecache which is extremely important and useful. I recommend either 2x8GiB = 16GiB memory or 4x8GiB = 32GiB for desktop systems at this time. Memory is cheap, and useful!
Thank you for explaining in much better detail the same point I was trying to make! :thumbsup:
I had built my system before 8GB memsticks were out, or I would have gone with 32GB system memory as well. I tend to upgrade on a 4-5 year cycle, and I am firmly of the opinion that the amount of ram in today's average desktop is far, far too low especially with how cheap it is. I wish most mobos had 6 stick slots or more, honestly.
 

jaqie

Platinum Member
Apr 6, 2008
2,472
1
0
I find this to be a peculiar design decision by MS. And a mostly wrong one too. Before putting the OS into a quiescent state, it should flush both the disk write and read caches. Because otherwise, you will run into filesystem corruption, should the filesystem be modified by an "external" OS (think dual-boot with Linux), and then the Windows OS un-hibernated with stale filesystem cache blocks, that then get written out.
I agree it seems like a bad decision on the surface, but MS has a 'solution' for this... if the disk data has changed since hibernate was started, it dumps the hibernate and does a normal boot cycle. I would rather have a choice of deep hibernate or shallow hibernate - being able to choose either method at will.