Why only 3GB RAM available out of 4GB?

Hi,
Could someone please explain why my system recognises only 3GB of RAM while I have 4GB (2x2GB) installed in a Windows 8 OS which is 64bit, I have enclosed few snips. Thanks.

 

that is normal for 32bit operating system as it can only physically see and use 3.1gb but i have no idea why it would do it on windows 8 64bit.
never seen or used windows 8 so this is one for the users.

 

Your Video card (or other hardware) is reserving the other 1GB of RAM.

 

Thank you guys, I see 1GB hardware reserved but when I used 3GB I didn't see the "Hardware Reserved", I could feel the difference between 3GB and 4GB as the system more snappier and smooth with 4GB.

 

Did your system recognize all 4 GB of RAM on the previous OS? Did you check your BIOS for any settings relating to RAM?

 

Probably using a chipset with only 32-bit addressing so no memory remapping. It's not that the hardware is reserving the RAM but taking up space in the 32-bit address range and because there is no re-mapping the RAM addressing is limited to what is left of the 32-bit addressing after the hardware has had it's take.

 

Anything between 3.8 to 2.8GB usable is "normal" as far as I've seen. Max. for 32bit system is exactly 4096MB and everything system needs (hardware, drivers) is reduced from that.

This. Intel 945 Chipset probably, paired with the T5600 CPU. I had the same in my couple old laptops, chipset is limited to 3GB and there's no way around it.

 

@ Tsunade_Hime,
I have replaced the 5610z MB with Travelmate 4200 (Intel 945) MB, I couldn't find any settings in BIOS for Memory but it says extended memory 4095.


EDIT:
In Task manager it says under Committed 1.1/3.9 GB, what does it means? Thanks.

 

Commit is the total amount of memory reserved by the OS for everything currently running IIRC and that includes both RAM and page file.

This should explain it in more details: http://blogs.technet.com/b/markrussinovich/archive/2008/11/17/3155406.aspx.

 

Which laptop is it? (If this in a signature, my app doesn't show signatures.)

 

It used to be a Acer Aspire 5610z(i943 chipset) but it now have Acer Travelmate 4200(Intel 945) motherboard.

 

The GMA 950 gpu will use a maximum memory of 224mb. So that is not it.

But if you look at the cpu, you see it is a T2250 I believe. That cpu is really a 32bit cpu. For example it can only address 32bit memory space. ARK | Intel® Core

So that is why you are limited to 3gb (or so) memory space. The gpu is using 224mb, so it makes for a total of about 3.2gb, which is normal for a 32bit system.

I know it is running a 64bit OS, but it is like a software emulation.

 

Thanks, I have T5600 and not T2250, as previous posters mentioned I think it's a BIOS restriction, these Acer laptops have all "Advanced" disabled in BIOS, I have to live with it and be satisfied as the system runs smooth and snappy.

 

It could definitely be a BIOS restriction. 32-bit can address 4 GB on any recent version of Windows, so it's not bitness of the OS limiting you.

 

Yes, you are right tijo, they released a BIOS with the 4GB support added (v3.50), I'm not going to flash the BIOS for the sake of an extra 1GB and risk bricking perfectly working laptop, may be next year when I am ready for a new laptop as an experiment, Thank you all for the help.

 

Bios updates are way safer on laptops than desktops. I wouldn't hesitate if I was you... the update from acers website for you is even a windows updateable bios. The only problem is they only have a 32 bit version.
If you are bored one night throw a different hard drive in the laptop. install a 32 bit os (preferably xp or vista) and install the bios update. as long as your battery holds a charge (incase the power goes out) and your system is virus-free, there is extremely little to go wrong. I update every system I sell to the most recent bios before I sell it just to ensure I wont have to troubleshoot some weird issue with the bios at a later date.
http://global-download.acer.com/GDFiles/BIOS/BIOS/BIOS_v3.60.zip?acerid=633643232632051506&Step1=NOTEBOOK&Step2=ASPIRE&Step3=ASPIRE%205610Z&OS=ALL&LC=en&BC=ACER&SC=PA_6
acers support site is basic but this is the link i came up with for your bios download. for the 1gb or ram its worth I would just go for it. most acers have a recovery process for a bricked bios too. theres not much reason to be afraid of a bios update nowadays.

 

Hi loafer987,
Thanks for the assurance, this is my real situation, I have changed almost everything inside my Acer Aspire 5610z except the outer shell, heat sink and fan.
Could you please tell me whether the changes will affect the flashing, I am afraid of verification by update utility, I have switched my MB from Acer Aspire 5610z to Acer Travelmate 4200 as my laptop had a 2GB memory restriction. Thanks.

EDIT: BTW, I have v3.32 BIOS at the moment, I don't have any wireless card and using D-Link 140n dongle, do I need to remove the wireless USB dongle when updating? Thanks for your time, much appreciated.

 

as long as you download the correct bios for the motherboard and you don't plug in or remove any usb devices while the bios update is installing you should be fine. after you update and reboot you should go into the bios and load the optimized defaults. That's really all there is to it. As i said before though don't ever try to install a 32 bit update from the acer site with 64 bit windows installed. This is the only variable to be more careful of. I have only ever bricked 2 systems to the point they were unrepairable. Once it was a power outage. (just terrible luck/timing) the other was a toshiba laptop running windows 7 64 bit and the update was downloaded from the 32 bit vista download page.

 

Also, the link I gave you was for the 5610z so find the correct one for whatever motherboard you are using.

 

Thanks loafer987, I have got few versions of BIOS from the same Acer-euro site for Travelmate 4200 MB, I'm going to flash today later on and let you know the outcome.

 

Hi loafer987,
After spending time creating CRISIS DISK and reading all the recovery procedures, it took less than 5 minutes to flash the BIOS( in 32 bit Vista), however it was worth it and I'm pleased that everything went well, the new BIOS didn't help my initial issue as it still show 2.99GB as usable memory. Your help and support very much appreciated.

 

No bios flash can change the chipset from 32bit to 64bit. At one point some of the patches just changed wording from "3GB available" to "4GB installed".

 

Still, even on 32-bit, he should get access to 4 GB - reserved for video - reserved for other hardware if the BIOS permits it. The latter is usually small, in the 100 MB range or so from my experience. That would mean close to 1 GB reserved for video which I would find surprising.

 

This is from my Desktop, MB: BIOSTAR N61PA
Chipset: MCP61


This PC was built in 2008 and my laptop was 2007 model, at least I have learnt what to look for in future purchase.

 

Otherwise I'd say yes but in this case: the i945 chipset is bugged. It is kinda hardware limited to 3GB, fact that I had to dig out for my nc8430 and tc4400 laptops in the old days Back then it didn't really matter because normal computer had 1 or 2GB ram anyways.

 

Interesting, didn't know about the firmware quirks.

 

Very true. The same limitation applies to *60 series ThinkPads, which will recognize 4GB in BIOS, but utilize only 3GB...

 

It isn't uncommon for 32-bit OS to access only 3GB.

 

The problem here is that even a 64-bit OS isn't able to "grab" more than 3GB...at least on the machines that I was referring to.

 

Same thing with the Dx20 Dell Latitudes.