How much of RAM do the x86 and x64 versions of Win 7 get to be loaded

Hi guys,

Consider we have installed Win 7 x86 on a machine with 4GB RAM. How much of that RAM will be gotten by the OS itself, to be completely loaded. What about the x64 version of Win 7?
What about if we have more or less RAM, please?


Thanks in advance.

Thank you. Your info was valuable and I appreciate you for it.
I didn't mean how much of the RAM do they can use!
For example you have installed a win 7 x86. How much of the RAM does that OS occupy at the first start for completely loading itself. That is, we should say how much of the RAM is used for loading the OS and the rest of the RAM is for subsequent operations?
Don't know could I convey my meaning or not.

My 4 GB system uses around 1.3 GB after a fresh boot. I have Windows 7 Home Premium 64 bit.

I very rarely use as much as 3 GB. Usually around 1.8 after several hours of operation with my normal programs running.

Franky said:

Thank you. Your info was valuable and I appreciate you for it.
I didn't mean how much of the RAM do they can use!
For example you have installed a win 7 x86. How much of the RAM does that OS occupy at the first start for completely loading itself. That is, we should say how much of the RAM is used for loading the OS and the rest of the RAM is for subsequent operations?
Don't know could I convey my meaning or not.

The amount of RAM used by the OS is not a fixed quantity but is highly dynamic. It depends on how much RAM is in the system, what processes are currently running, what they are doing, and system activity earlier in the session. The system memory manager is always in control of memory usage with the goal of maximizing overall system performance. System memory usage at bootup may be quite high but that is only because there is currently no better use for it. When a large application is loaded this usage will automatically be trimmed back, drastically if necessary. The usage of individual processes can vary by a factor of 100 or more.

Memory usage in any modern OS is extremely complex.

Due to addressing constraints not all RAM in a 32 bit system may be accessible. A 32 bit OS has a maximum 4 GB address space but a portion of this must be used for things other than RAM. Generally about 3.25 GB RAM will be accessible but it can be more or less, depending on hardware details. If RAM is being used by the video system (common in low end systems) this will further reduce RAM availability.

Do not attempt to read too much into the numbers quoted above, they are meaningful only on the system in question and under the specific circumstances under which it is running.

Within reasonable limits the more RAM in the system the higher will be the usage. It was designed to work that way. To be of value RAM must be used, not sit idle. I have run Windows 7 on my system (normally with 4 GB RAM) with as little as 1 GB RAM and I am sure it will run with less. Obviously memory usage must be trimmed back to make this possible. Everything will work as before except performance (particularly response time) will suffer.

Always remember that in Windows memory usage is highly dynamic. If you don't understand that very little about memory management in a modern OS will make much sense.

Thank you all very much.
OK LMiller, but please let me clarify the issue a bit more.

Consider you have a sample PC with 4GB of RAM and the processor capable of acting on both x86 and x64 OSes.
You format the C: drive and do a fresh install of Win 7 x86 on that drive. Then you install the drivers. OK, stop. So far, nothing is installed except the OS and its drivers and we don't do any function. Now how much of RAM will be gotten by that x86 OS? What if it were x64?
At the most clear language, I want to know that, how much (in MB) is the difference between the amount of the RAM occupied by 7 x86 and 7 x64 when there is no function and third-party app installed.

Can we say, it's 1GB for x86 and 1.5GB for x64 roughly?

It appears you are looking for a simple answer to a very complex question that has no simple answers. Nothing about memory management or usage in a modern OS is simple. The amount of memory used by the OS alone at bootup depends on many factors but RAM size would normally be the most important. Windows 7 will not normally install with less than 512 MB RAM but with some trickery it is possible. I have heard of Windows 7 running on as little as 128 MB RAM. In that case usage at bootup would approach 100% or close to 128 MB. With 16 GB or more RAM the usage would be several GB. All that variance with the exact same OS installation.

But even then the usage at bootup is of little importance because it is not a fixed quantity. The OS might consume several GB memory at bootup but that will be automatically trimmed back, to as low as several hundred MB if there was extreme memory pressure, such as running several very large applications. I have seen this happen.

A 64 bit OS will of course use more memory than a 32 bit version. As I have emphasized it is impossible to provide any specific and meaningful values. 1.5 times more might be a reasonable difference if RAM is high enough not to seriously restrict usage. But that number is of little real value.

I cannot give a simple answer to your question because none exists.