Win7 32bit is able to
address full 4GB when physically available, but it reserves some space for BIOS devices and as the largest part GPU-memory
address-space.
Considering it is a laptop - wether it is using VGA with shared or dedicated memory - It actually
addresses your VGA RAM and that means that
this space is reserved and not usable originally by a 32bit-OS. But when your processor and OS support PAE you can use that invisible memory...
BUT NOT SHARED VRAM - which look like the same in WIndows!
Windows shows
"physical available" at first and
"non-reserved/free/usable addressable" in exclamation marks behind.
I guess it shows you that you have 3,5GB available and 2,5GB usable... right?
It does not show you that you have 4,0GB available and 3,5GB usable like you say... right?
Or is it 3,75GB available and 3GB usable....
This information is very important!!
Have you simply read the manual of what you are doing there???
Look, here:
Unified Invisible Memory Management Interface
http://www.romexsoftware.com/en-us/know ... rface.html
1. Hint:
With the help of these two options, UIMMI is able to reserve the front-end or back-end address space, or both. Usually the reserved space is for on-board video adapters, which may also use Invisible Memory as their shared video memory, in order to prevent possible conflicts.
2. Hint:
Tip: How do I know which end of Invisible Memory is used by on-board video adapter?
Well, because there are lots of motherboard manufactures and models, we cannot classify and list all motherboards. However you may know it by yourselves with the following practice.
1. First, reserve either end of Invisible Memory as much as VGA shared memory.
2. Then try to fill the remaining Invisible Memory with any data.
3. If you find that the display of screen becomes messed, it means the remaining Invisible Memory overlaps with VGA shared memory. Try to reserve the other end of Invisible Memory and repeat step 2.
In that situation or when your motherboard addresses 512MB shared (+512MB address space) to primary VGA and have a second GPU with 512MB dedicated ram, you have
ONLY 1024MB PHYSICAL FREE INVISIBLE MEMORY. This will end up in FC/PC activating 100% of your free ram by moving the address space into virtual area that is not physically mapped or in numbers a total of 3584MB (4096MB - 512MB shared video-ram) comparted to only 2560MB before will be available.
In other situation or when your motherboard addresses 256MB shared (+256MB address space) to primary VGA and have a second GPU with 512MB dedicated ram, you have
ONLY 768MB PHYSICAL FREE INVISIBLE MEMORY. This will end up in FC/PC activating 100% of your free ram by moving the address space into virtual area that is not physically mapped or in numbers a total of 3840MB (4096MB - 256MB shared video-ram) comparted to only 3072MB before will be available.
In other situation or when your motherboard addresses 512MB shared (+512MB address space) to primary VGA and have no second GPU, you have
ONLY 512 MB PHYSICAL FREE INVISIBLE MEMORY. This will end up in FC/PC activating 100% of your free ram by moving the address space into virtual area that is not physically mapped or in numbers a total of 3584MB (4096MB - 512MB shared video-ram) comparted to only 3072MB before will be available.
In other situation or when your motherboard addresses 256MB shared (+256MB address space) to primary VGA and have no second GPU, you have
ONLY 256 MB PHYSICAL FREE INVISIBLE MEMORY. This will end up in FC/PC activating 100% of your free ram by moving the address space into virtual area that is not physically mapped or in numbers a total of 3840MB (4096MB - 256MB shared video-ram) comparted to only 3584MB before will be available.
In all cases of shared VRAM from system-ram: You should first find out whats the primary VGA ram-shared area and exlamate this space from UIMMI via settings.
This is really important because FC/PC has no idea to determine what address-space is PHYSICALLY reserved for vram.
In other situation or when you have no shared system-ram to primary VGA and have GPU with 1024MB dedicated stand-alone-ram, you have
ONLY 1024 MB PHYSICAL FREE INVISIBLE MEMORY. This will end up in FC/PC activating 100% of your free ram by moving the address space into virtual area that is not physically mapped or in numbers a total of 4096MB comparted to only 3072MB before will be available.
In other situation or when you have no shared system-ram to primary VGA and have GPU with 512MB dedicated stand-alone-ram, you have
ONLY 512 MB PHYSICAL FREE INVISIBLE MEMORY. This will end up in FC/PC activating 100% of your free ram by moving the address space into virtual area that is not physically mapped or in numbers a total of 4096MB comparted to only 3584MB before will be available.
In other situation or when you have no shared system-ram to primary VGA and have GPU with 256MB dedicated stand-alone-ram, you have
ONLY 256 MB PHYSICAL FREE INVISIBLE MEMORY. This will end up in FC/PC activating 100% of your free ram by moving the address space into virtual area that is not physically mapped or in numbers a total of 4096MB comparted to only 3840MB before will be available.
Maybe you got both primary and secondary VGA or only one shared or dedicated, sounds like one of them, but your description doesn't clearly state... not even whats the laptop-model, so I tried to answer for all cases, hope you see through. All questions are rhetorical.
To make it easier to understand:
1. FC/PC can only activate "virtual" reserved address space like devices-address space, that windows isnt itself able to virtually abstract at higher spaces, so it uses the physical space.
2. FC/PC can NOT activate "physical" reserved address space like shared VRAM... it is simply not physically free, so beware.
Hope it helped.