8 GB DDR3 RAM, only 7.74 GB useable?!

[Rob Riot UK]

I'm confused. I installed 8 GB DDR3 RAM and in BIOS and my O/S it only says 7.74 GB is useable. What could be the reason? My motherboard is a ASUS M4A785TD-M EVO. It does have onboard graphics, but there is onboard 128MB DDR3 1333 memory that should cover that.

What could it be? Do I need to alter something in the BIOS?

 

[roonj]

Throw it all away and start over, you live where?

 

[Rob Riot UK]

Well I wouldn't go to those lengths obviously!

Just curious as to where that small amount has gone (I know it is nitpicking)

Just looked at the Performance report in Windows and this is what is listed for the RAM:

6458MB Available
5522MB Cached
7935MB Total
8192MB Installed

257 MB Hardware Reserved
1417MB In Use
62 MB Modified
5460MB Standby
998MB Free

 

[fatsauce]

Could be the bios using some of the ram for itself or the OS using some or maybe the video card or the pci-e bus, and for DOS as well..there might be a memory remapping in your BIOS if u want to try that to get more memory to use..but i heard u have to reinstall your OS..But trust me its the hardware, OS and BIOS taking that memory for itself..u wont see it when u check for it in vista or xp but its actually being used.

check this site out for an explanation http://www.codinghorror.com/blog/archives/000811.html

 

[Rob Riot UK]

Well I've done a bit of research and I think the reduced amount is due to some being reserved for the onboard graphics as I have it set to UMA+SidePort in BIOS. (The lost 257MB).

While I'm on the subject of RAM though I was curious as to how the system dictates what memory is seen as "Available to programs" and which is "Used for Cache". Anyone know?