256MB RAM Reserved?

[dpastuszczak]

I built my father's PC a few years ago, but only recently noticed that Windows is reporting 8GB of RAM installed and 7.75GB usable. There is no discrete graphics on the mainboard, so what could it be? My system, running Windows 7 Ultimate SP1 64-bit, shows 16GB of RAM installed, but doesn't show a lesser, usable amount. Why does my dad's PC have 256MB of RAM reserved, and mine has no reserved memory.

My dad's system:

• ■Mobo: Gigabyte GA-970A-UD3P.■CPU: AMD FX-6300 X6 @ 4.0GHz■RAM: 8GB DDR3 1866MHz Dual-Channel (2x4GB)■GPU: Radeon HD 6670 dedicated graphics■STORAGE:
  • Samsung 840 EVO 250GB SSD
    WD Blue 1TB HDD x2 (RAID 1)
  ■OS: Windows 7 Ultimate SP1 64-bit

 

[PC Tailor]

https://support.microsoft.com/en-gb/help/978610/the-usable-memory-may-be-less-than-the-installed-memory-on-windows-7-b

Common in many Windows 7 setups.

 

[dpastuszczak]

https://support.microsoft.com/en-gb/help/978610/the-usable-memory-may-be-less-than-the-installed-memory-on-windows-7-b

Common in many Windows 7 setups.

I was aware of some of those points, but it doesn't tell me how to find out what is reserving all that memory. I checked the resource monitor on my PC and it says I have 34MB of RAM reserved for hardware, but my dad's PC has 258MB of RAM reserved for hardware. Then I dove a little deeper, I ran MSINFO32 and looked at MEMORY under HARDWARE RESOURCES. Every device on my dad's PC used a couple hundred kibibytes at most, except the resource called system board, which occupied the memory range 0xE0000000 to 0xEFFFFFFF...that's a whopping 255MB. So I looked at my PC, and I have more devices allocated to reserved memory, [strike]including[/strike] as well as the same system board device occupying the same memory range, 0xE0000000 to 0xEFFFFFFF, but only 34MB reserved on my PC.

So I'm back to square one, I don't know what's eating his RAM. There was a manufactured defect in the motherboard when I first set it up, and one of the diagnostics I ran was memtest, to make sure it wasn't the RAM, but every bit and byte checked out, and the mainboard ended up getting repaired under warranty by the manufacturer.

 

[hang-the-9]

My work laptop shows 333MB hardware reserved, if you are trying to find out if this is an issue you need to fix, it's not.

You are doing a good job researching what is using up the memory, but I suggest you don't try to "fix" it. Often trying to fix something that may seem like an issue ends up breaking more things or making a system unbootable.

 

[dpastuszczak]

My work laptop shows 333MB hardware reserved, if you are trying to find out if this is an issue you need to fix, it's not.

You are doing a good job researching what is using up the memory, but I suggest you don't try to "fix" it. Often trying to fix something that may seem like an issue ends up breaking more things or making a system unbootable.

Thanks for the vote of confidence. At this point, I just want to know what it is, whether it's "fixable" or not, and googling this topic just gets me forums asking how to fix it, nothing about how to see what hardware is using how much RAM. I expect to see a lot of memory reserved for discrete graphics, but there is no such thing on the board in question.

 

[gamerk316]

The 256MB block is probably shared VRAM for the embedded GPU if I had to take a guess. It's also possible the OS it intentionally not using anything below 0xF000000; OS's typically allocate RAM from the top on down in order to avoid legacy x86 memory holes, so it's possible everything below that address is simply reserved for HW addressing, even if it's not actually being used.

 

[dpastuszczak]

The 256MB block is probably shared VRAM for the embedded GPU if I had to take a guess. It's also possible the OS it intentionally not using anything below 0xF000000; OS's typically allocate RAM from the top on down in order to avoid legacy x86 memory holes, so it's possible everything below that address is simply reserved for HW addressing, even if it's not actually being used.

You missed 1 important detail:

I expect to see a lot of memory reserved for discrete graphics, but there is no such thing on the board in question.

Yeah, no embedded GPU on the board. Everything you said has already been addressed, if you just bothered to skim through the 5 short posts before yours.

The question now is why does the PC in question have 258MB reserved, and mine only has 35MB reserved? They're both Gigabyte boards, the biggest difference being his is an AMD 970 chipset, and mine is a 990FX chipset, which has more PCIe lanes, SATA ports...more hardware in general, so byte for byte, my rig should have more reserved RAM, in theory. Ultimately, I just want to know why there's a discrepancy in the first place.