how much ram is actually being used?

Without knowing the specs of your computer, there is no way to help you.
 
XP has a limit of 4gb of ram. While this is sufficient, it also depends on your CPU. If you have to overclock your CPU because you need better performance, my guess is you have an older computer. Again, we can't help without knowing your specs.

A Windows OS system never "runs out "of RAM. It is designed to always map out a portion of the hard disk drive to use as "stick RAM". This is called 'The Swap File'. This swap file is 'laid out' to behave as actual stick RAM modules and all programs sees it and uses it in that manner.
The main drawback is that, it is slow (can be thousands times slower). Imagine sending a messenger to a warehouse (data) 10 miles away. Stick RAM is like using a car--Swap File is like using a bicycle. The more Stick RAM you have, is like having a whole lot more cars for courier.

You can't compare the use of ram on a 32bit OS and CPU performance.

Once you move to a 64bit OS it opens up completely different possibilities for software, not only in how much ram you need but how CPU performance changes.

my pagefile is static 512 megs, so whatever ram needs are not being supplied by the pagefile.  Also, if 32 bit Sonar only uses 2 gigs of ram, why don't I ever experience some sort of random crash or inability to load yet another plugin? 

We've become accustomed to what is a literally unimaginable amount of RAM. Think about it: a gigabyte is 8 BILLION tiny switches. It boggles the mind. The first computer I programmed had 4 KILObytes of RAM, and I managed to write video games with it. 10 years later I was working on systems that ran entire companies with hundreds of users, on 8 MB. My company's high-end box was a couple million dollars and supported a maximum of 128MB. Later on I was coding on Sun SPARCstations, which offered an unbelievable 16MB - on a desktop! The Space Shuttle was designed on computers like that.
 
Increases in available RAM have made programmers lazy. No longer do they carefully allocate exactly how much memory is needed and dutifully return it to the pool immediately after it's no longer needed. As RAM increases, so does the need for RAM. But it's still possible to write useful software that runs in a few hundred kilobytes just fine. SONAR is one such program, having its roots in a time when far less than a gigabyte was the norm. Load up an empty project and note the RAM usage - it's pretty small.
 
Then start adding plugins and watch the memory usage rise. Most effect plugins add so little as to barely make a blip. Start recording some audio. Again, memory usage rises very little per track. Overall system memory increases as Windows attempts to buffer all that audio data, but that's in the disk cache and most doesn't come out of SONAR's share. You can in fact have a huge all-audio project and easily remain within SONAR's 2GB limit.
 
The big RAM-gobblers are sample libraries. My largest one wants over 3GB, but Kontakt also has its roots in times where 1 or 2 GB was all the machine had, and uses memory frugally. I routinely have a dozen or so sampled instruments loaded under XP without exhausting RAM. However, those libraries are carefully chosen for efficiency (one of the reasons SampleTank 2.5 is still a favorite). If I could afford to, I'd happily replace my aged DAW and O/S and load that sucker up with as much RAM as it'd hold. In the meantime, I practice stingy memory management and freeze a lot.
 
And the funny thing is my technological restrictions do not creatively stifle me in any way. If anything, the opposite is true: the emphasis shifts from what cool sounds I can layer on to the music itself.
 
At the moment I am exiled, not only from recording but from even strumming a guitar, leaving me with only an MP3 player full of gigabytes of other peoples' music. I've been listening a lot and marveling at what can be done with a guitar and a piano.
 
To the OP: yes, you have about a gigabyte and a half to play with, period. Fill it with music.

ditto on the kudos to 'Flipper. I listened to almost the entire "My Stuff" last week. I was very impressed by the production quality as well as the musical content. 
 
Michael
 
 
 

I can get another 4 gigs of ram for $15, which would bring me up to 8 gigs total.  Or I could spend $80 for two 4 gig sticks and have 12 gigs ram total.  Given the price differential, seems like 8 would be fine.  Comments?
 
Phenom II x4 945 under win7-64bit.  Will eventually spring for FX6350 ....

Where did you find 4GB for $15? It wasn't out of a truck at the Home Depot parking lot, was it?

Ebay 2 sticks of Corsair XMS3 2GB 1600MHz $17.60 plus $5 shipping.  Didn't read the bit about "no returns".  Certainly hope somebody outbids me!!!  Here is why:
 
I've been working on a project for a choir director with vocal track, voc dbl, 3 harmonies each dbl-ed, so that is 8 vocal tracks.  Because she keeps going sharp or flat, and because I am trying to learn how to use X3 and Melodyne (since I can't get V-vocal to work), I wound up putting a region FX on every vocal clip through the whole song.  My memory indicator indicated I'd used 7.9 gigs of ram on my 4 gig system.  So 8 gigs is NOT enough!!  So probably the answer to my question is you need at least 16 gigs or more ...  
 
{PS:  PLEASE go and outbid me.   Thanks. }
{ Note:  You are now the owner of some crappy used memory that is too small and probably won't pass memtest.}

I see a lot of Forum readers referring to RAM providing better audio performance so I though some of you might want a clarification of what the various solutions really provide.
System Memory RAM is needed to handle VI's (Virtual Instruments). The more Ram that the system has the more VI's can be loaded & no nasty Clicks or Pops. But, if you stream the samples from the hard drive the RAM is of little value to the audio performance.
 
#1 - The best improvement for plug ins comes from upgrading from a 32 to a 64 bit operating system (Win 7 64 bit OS). Before doing the upgrade you will need a 64bit capable motherboard in your computer.
#2 - The next investment would be moving to a Quad Core CPU with at least 6 to 8mb of Cache on board. Not an AMD but an Intel!
* With my old Intel 2 core CPU I had 2mb of Cache & I had nothing but audio problems. The sequencer would stop and display the red alert message "Audio Dropouts" continuously.
The audio effects such as reverbs, & EQ's are all handled by the CPU cache & not the RAM.
 
The CPU speed is not very important for recording audio! Can that be true??? Yes!
I have an 8 year old Acer laptop running 32 bit XP with an Intel 2.1 ghz dual Core & it has 4mb of Cache. I record 32 channels of audio on a PreSonus 24.4.2 mixer and a Mackie 1604 connected VIA Firewire 400 & have never had any issues with audio dropouts, pops or clicks! When I started I was using Sonar 5.0 (set to 128 samples for latency) & through all the upgrades have never had any issues with audio. 
Another important link in recording if you are using external hard drives is to connect them through Esata & not through USB or Firewire. I have never been able to use USB or Firewire without audio clicks or pops. I experimented early on & have stuck with what works rather than futzing around with stuff that does not perform.
Another warning that I will offer is the use of Intel vs. AMD. Cakewalk & recommended computer assemblers all stick to Intel CPU's so what does this tell you.  There's a number of diehards that always go against the norm & wind up having more than their share of problems.  
For those of you tampering with CPU speed re-read this post & do yourself a favor! Stop futzing around with what you don't understand. Music software does not benefit screwing around with the CPU speed!!
 
So I hope this helps because I see so many posts that all stem from the same problem! Lack of knowledgeable computer recording information.
 
Good Luck!