Windows 7 x64 4GB ram use only 3.1 GB like x86

Question

I have windows 7 professional 64bit with 4GB of RAM.

It displays in System Properties 4GB installed and in Resource Monitor correctly shows 4096MB and 2MB reserved for HW.

The bios shows 4096MB and the overlapped memory is on. Motherboard is ASUS p7p55d-e.

The OS uses only 3.1 GB ram as if it was a 32-bit os. Why?

Tried changing bios configuration regardless and set windows boot option to use /not use Max memory and so on....

BUT I still have the limit of 3.1GB RAM max allocated.

Can someone help me?

Maybe the OS installation is corrupted? Some new update? Or something else software/OS related? Or... I don't know....

With the command line with administrative rights

bcdedit /set pae ForceEnable

seems to fix the issue and only increases to 3.4GB instead of 3.1GB.

Any idea how I can use all of my 4GB ram?

Thanks.

EDIT: yes os is x64 As MichaelKjörling said it's seems working as if it was a 32-bit OS

currently with the

bcdedit /set pae ForceEnable

the ram peak it's at 3.5/3.6 GB

Using SysInternal Process Explorer set refresh interval to 0.5s and saw the peak ram in the graph is 3.5/3.6 GB RAM.

With VM on it's stable on 3.1GB and doesn't go over it, but I think maybe it's a win7 memory manager? or something like "superfetch memory caching"?

[cant'post image need 10 reputation, sorry it's not my fault this time :)]

thx for help.

PICTURE:

The peak is 3.5 / 3.6 GB

PICTURE 2 Monitor Resource (IT lang)

from left to right in the legend:

• Reserverd (gray)
• Used (green)
• Modified (orange)
• StandBy (blue)
• Free (light blue)

P.S.

My question is not related with the others one tagged, because it's a differnt problem:

It is no BIOS related, neither some "Advanced Boot Option in the OS".

otherwise I've not 4 GB Tot ram available (see Pic.2)

thx for help.

FOUND BETTER ANSWER HERE:

Windows 7 Tweaks, Tricks,...

Optimize Memory

In addition to turning OFF unnecessary processes, there are a couple tweaks that will force Windows to use MORE of the ram memory than the system is set to use by default. Using MORE memory FOR YOUR applications means the system is faster and there are fewer hard drive accesses. You want more memory to be USED by YOUR applications... that's why you paid for it.

Run Regedit and go to:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\ FileSystem\NtfsMemoryUSage

Change it from 0 to 2.

Just below that location is this key, this registry tweak will increase your hard disk cache size The Large System Cache option is one that can improve your disk I/O performance up to 50%! Change from 0 to 1.

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SessionManager\MemoryManagement\LargeSystemCache

By default, Microsoft probably keeps the memory demands set as low as possible at installation - so they can sell upgrades to a wider market of users who have older computers with limited ram.

Solution 1

I don't see a problem. Your 2nd Picture is showing 4GB of RAM installed. 2.6GB is being actively used and 1.4GB is standby RAM which is like a cache for old/pending data/files that costs very little to keep around but can be freed up if an active application needs it. This is normal and by having standby data it makes your system faster as its not disk bound all the time.

Just because your peak usages of 3.1GB/3.6GB does not mean that you only have 4GB. The system is reporting that the applications are not filling the RAM and its using the rest for cache. Which is great. 8GB in that system might be overkill.

Solution 2

BIOS update? Seems that the OS does not get the full memory - PCIe buffer space not being remapped by a bad bios / crappy chipset. X64 OS can not work around that limitations, sadly.

Comments

[user]

Wait a minute. The title says x64 so 64-bit, but the question says the OS ... is a 32bit os. Please double-check the system properties (Win + Pause, or Control Panel - System); is your installed OS 32-bit or 64-bit? If it's actually 32-bit, that would perfectly explain what you are seeing.

[ta.speot.is]

@MichaelKjörling I think he meant to say The OS uses only 3.1 GB of RAM as if it was a 32-bit OS

[user]

@ta.speot.is I think it's worth getting clarification on.

[Alvin Wong]

Where do you get the information that the OS only uses 3.1GB ram? (Perhaps provide a screenshot so we can prove you wrong)

[Raffaello]

[update question: yes i'm using x64 os, and monitor ram with SysInternal process explorer] Maybe it's somenthing related with Power Saving too?

[Little Helper]

You have enough rep so now you can post the screenshot :)

[吴环宇]

Check the Memory Hole (or something similar) setting in your computer's BIOS. My computer mapped the memory in such a way that only around 3 GB was available before switching this setting. Check this answer.

[Magnetic_dud]

I had a similar problem, 8 gb ram, but win8 x64 said 3gb available. It turned out that booting from an SSD was the problem. Booting from an HDD "fixed" the problem. I guess it's a big BIOS bug of my mobo

[吴环宇]

@Raffaello: so could I. Still adjusting the memory hole setting resolved it for me.

[Indrek]

@Raffaello According to the screenshots you have 4 GB of RAM available, and are currently using ca. 2.4-2.6 GB of it. I can't see anything that suggests that your computer "uses only 3.1 GB ram" or "the ram peak it's at 3.5/3.6 GB". Where are you getting those numbers from? What processes are running at that time? What are you doing to ensure that the computer uses as much RAM as possible?

[0xC0000022L]

Use ImDisk to create a RAM disk of considerable size and see whether usage goes up ;)

[Raffaello]

Bios is updated with last version.

[TomTom]

Then crappy hardware. Happens. Basically the PCIE-Area is mapped into the lower 4gb memory - so you have less memory available. Time to buy more memory.

[Raffaello]

my peek usage was 3.1 before ran the bcdedit command line, after it was on 3.5 / 3.6 GB. Testing with mem opt that alloc all available memory. Yeah, maybe it's memory optimizer too fault. :) thx

[Raffaello]

maybe you're right.. thx.