I just noticed that, as pictured below, my computer is using shared memory & a lot of it. I have 512 mb of dedicated video memory which is more then enough since I don't do heavy gaming. If I can free that up by disabling the shared memory I'd like to since I am using Vista.

Hardware Scan

Hi ,

System Video Memory: this one is usually 0. When it is NOT, this tells us there's an integrated onboard graphics that comes with little / more likely none of its own ram & is using a portion of system ram for itself.

Dedicated Video Memory: the ram that the graphics adapter already brings with it, PLUS "any system ram it wants to exclusively appropriate for itself"(other subsystems would not be allowed to use it ever).

Shared System Video Memory: the portion of available system ram that the graphics system can borrow if / when it is available. In other words, this is really first-come, first-served: the shared memory is available to the graphics system & to other non-graphic subsytems... neither can appropriate memory in use by the other.

NOW...the video card is going to tell the system how much system memory it's going to allocate for its use:
IF it does this during POST, thru a call to the BIOS reserving a ram amount, windows will not 'see' the subtracted amount.
IF instead it does this during startup @ driver initialization, windows 'sees' this.
However, the end result is the same no matter what windows reports: dedicated system memory is NOT available to the system...& shared memory may or may not at times.

Settings for the shared memory are set at manufacture . Basically Vista's OS graphics and themes require the shared memory but as stated above they are not in use as per se but as and when needed . There are in some BIOS , settings to reduce the shared memory but on WHQL assigned drivers the bios will be set normally by your motherboard in conjunction to the drivers used on your GFX card . If you are unable to change any settings in your BIOS ( onboard gfx if enabled , etc ) you can always find forceware compatible software to change memory settings . Basically it's comparable to overclocking a card and if not into heavy resource gaming isn't particularly neccessary . On various posts I've surfed through this morning I've noticed the shared memory values for different O/S vary due to the graphics requirements difference . Say Vista running Aero theme , using stardock and a the side bar will have a considerably larger shared memory requirement than XP running in standard XP mode . Here's a post of my GFX Adapter settings - I use high resource GFX games but the dedicated memory is still assigned to system use alone . All my GFX in game run smoothly , my pc boots and runs smoothly - even on dual monitor using high resource games .

I have enough dedicated memory that I know that I probably don't need shared memory even on Vista so I would like to disable it. Are you saying that its not possible to disable it? There isn't anything about it in the BIOS settings.

Hi ,

I've done a little more research into shared video memory . Apparrently Nvidia and ATI are the main monopoly market GFX cards . ATI uses a " hypermemory " system when allocating shared memory with a factor of x2 and Nvidia uses a " turbocache " system that uses a factor of x4 , these are factors dependent upon installed RAM / Dedicated memory. As you can see on my Nvidia GFX card with 4 gig of installed Ram running Vista Ultimate approximately 1/4 of my installed Ram is shifted to " shared memory " ( x4 ) . Basically these are resources that are allocated for aperture size or pci-e addressing - lots of " leave alone " , " not important " , " add more ram " but this is one of the few pages I found that is actually of any use and specific to using the BIOS to change or remove the shared memory .

How to Configure Shared Memory Through BIOS | eHow.com

I think it's just basic market manufacture standards that sets the shared memory allocation allowing for the use of high end multimedia apps . Hope that helps .

I believe that this & for computers with integrated chips & my guess would be for older computers. I've looked in my bios & I didn't find any shared memory settings. Of course I don't have integrated graphics. Thanks for trying though.