Diff.between "available" and "free" physical memory?

Guys... I believe I have a problem:
Total: 4024
Cached: 1721
Available: 1664
Free: 1

Recently I have been having "MEMORY_MANAGEMENT" Bluescreens while gaming or using many tabs on Firefox... is this the reason? I always seem to have 0 - 160~ in the Free category and performance has become sluggish lately. Should I buy new RAM or should I just flat out replace it? Like I said, I have been having MEMORY_MANAGEMENT BSODs and I think this is the reason. I am thinking about buying another 4 GB of RAM for my system. Good idea? please help.

P.S. I am running 1333 Mhz RAM btw.

i was looking at task manager. But even in resource monitor it has limited free ram.

But wait, that doesnt matter right? only "available" matters right?

For monitoring system resources, I find Resource Monitor better than Task Manager........Click Start > type Resource Monitor and there it is. It may make things a little easier to understand.

Memory management in Windows is complex and follows principles that are not obvious and may at times seem to make no sense. But there is method in the apparent madness.

Free memory: This is memory that contains no useful data. It is expensive fast memory just sitting there, consuming power and providing nothing in return. You don't want it and you don't need it. The only good thing about it is that it can immediately be taken out of unemployment and set to work. The ideal would be for free memory to be zero at all times but we aren't there yet.

Available memory: This is the sum of memory on the free list (bad), and the standby list (good). Memory on the standby list can also be immediately be put to work for any application. But what sets it apart from free memory is that it contains useful data and code, it just hasn't been recently used. This memory serves a dual role. As mentioned it can be given to any application. In addition, as it still contains the original code or data it can be given back to the original application it belonged to. In the resource manager of Vista and later you can see the values for free and standby memory. The value for standby memory should be high and free as small as possible. Standby memory also exists in XP but it takes some sophisticated tools to see it's value.

Cache memory: This is the sum of the file cache and the standby list. The file cache contains a copy of file data that has been recently accessed. If it is needed again, as often happens, it can be more quickly read from RAM than from disk. The file cache and the standby memory are both a form cache so it makes sense to show them together. A high value is a good thing. If an application needs more memory the size of the file cache will be trimmed if necessary.

Please note that the above is a highly simplified description of what is really a very complex process. The system memory manager will always try to assign memory where it will do the most good, and keep the unemployed free memory as low as possible.

cdonner said:

Unfortunately there is a bug in Windows 7 related to NUMA (non-uniform memory architecture) that will cause issues on certain platforms when the amount of Free memory goes down. For instance, on my Thinkpad T410 with 8GB of RAM the Free memory will approach zero when I load a large VM. When I stop the VM and exit VMWare, the Free memory does not recover - the memory remains allocated by the cache.
The problem with NUMA is that it prefers to allocate memory from banks that are attached to a CPU core (hence non-uniform, i.e. not all memory is considered equal). Unfortunately, the Windows 7 NUMA bug prevents memory from being allocated that is in the Available pool in this scenario. Since I have no Free memory, the machine begins to swap madly when I restart the VM (the same or another one does not matter) and freezes up for minutes - even though there are over 4GB "Available".
So, despite of what the others have said, the amount of "Free" memory is more important than what's in the "Available" pool.
There is a hotfix for this issue:
Poor performance occurs on a computer that has NUMA-based processors and that is running Windows Server 2008 R2 or Windows 7 if a thread requests lots of memory that is within the first 4 GB of memory

Hi cdonner and all,
I don't know if you're still there after 2 years from this post .....
I have a Thinkpad T410 with Win7 64bit 5GB RAM and the same issue with virtual machines, both VirtualBox and VMWare Player, lot of available memory but VMs not starting with diagnostic reporting not enough memory.
3GB available memory and VM configured for 512MB RAM.
All was perfectly working on the same PC when it was WinXP with even less RAM (3GB).
Is there any news from this front?
I have a corporate PC and I cannot install hotfixes
I wonder if after 2 years Win7 has not yet resolved this kind of issue?
Hope to find some help, I really need to run VMs.
Thanks in advance
ViSco

LMiller7 said:

The ideal would be for free memory to be zero at all times but we aren't there yet.

A high value is a good thing. If an application needs more memory the size of the file cache will be trimmed if necessary.

Well, I have Windows 7 64bit and 4GB of RAM 512MB being used by on board Radeon and often have FREE memory around 15-20 and sometimes single digits but what I can' figure out (if anyone can shed some light on this) is why if I have anywhere from about 900MB -over 1GB, like 1200MB or so, I am getting constant 'Out of Memory' warnings while running Google Chrome and also the old 'Low memory' Telling my I should close 'The Program' and then it usually list 'Google Chrome' or 'Desktop Gadgets' or some offending, memory hogging program. I don't see why it would warn me I am running out of memory consider I still have around or close to 30% of the memory still available.

This problem has driven me crazy ever since I have installed Windows.