Memory Remap to see 4GB RAM on VGN-AR31S, VGN-AR21S, VGN-AR41S

Hi,

I own a VGN-AR21S, but the following is also true for the 31 and 41 series and lots of other models.


Although the specs say that the max supported ram is 2GB I upgraded to 4 GB without problems, as the chipset supports them.

Well, almost. The problem is that the BIOS does not do the so called memory remap, and thus the upper 1 GB cannot be seen and the system reports 3GB available (on Windows 7 x64, but also Vista, Linux, etc).

I already upgraded the BIOS to the R0200J6 version supported by AR31S in order to enable VT (through the notorious symcmos hack), thus I was wondering:

Does anybody know if it's possible to upgrade to later BIOS versions? (e.g. the R2090J8 supported by the 71 serie which fully supports memory remap)?


Thanks!

Alex

 

Hello Alex, I have the same problem, did you find the solution ? can the Ar21S Hold the ar71s bios ?

 

I think you can forget it.
AR21S and AR71S don't have the same architecture: Napa on AR21S and Santa Rosa on AR71S.
Napa supports up to 4GB RAM (In the pratice, I only see 3GB max), and Santa Rosa supports up to 8GB RAM.
Updating to AR71S's bios only damages your AR21S

 

can you tell me where can i download the original bios for vaio vgn-ar71s or vgn-ar71m,or if you have it just upload it please.

thanks

 

umhhh..... pratically I have a notebook payed a lot of money to trash because of the ram lack .

 

Time to get a new laptop

 

the problem is that for me AR21S is OK (really powerful machine), i'm perfectly satisfied under each point of view, the only thing the really hurt me is this lack of memory , can I buy another laptop just because of the RAM ?

 

Hi,
I have the same problem,
Recently i upgraded my vgn-ar31s with 4gb and only recognizes 3gb.
Any bios mod or anything else works?
thanks

 

Hi,
I have a Sony Vaio VGS-AR21S with NVIDIA GeForce GO 7600 GT, and upgraded RAM from 2GB ("2x1GB 2Rx8 PC2-4200S-444-12-E0") to 4GB ("crucial 2x2gb 200 pin ddr2 sodimm pc2 6400 cl6") and Windows 7 64-bit with BIOS R0160J6.

I was told that the 6400 RAM was backward compatible with the 4200, and thought that the 64-bit Windows 7 would recognise the 4GB RAM. (motherboard i945PM should hold a max of 4GB according to manual).
The system picks up 3GB once windows starts, and works well with it.

The problem is when booting up. I am unable to start Windows in SAFE mode (F8) or install Linux as the graphics are almost non existant. On pressing F8, the screen is totally black with no text and the Linux install screen is just one colour with no text either!
Same thing happens if I install 3GB RAM!

However, if I put the original 2GB RAM back into the Laptop, the Safe Mode works and I can install Linux!


So, is there a problem with the extra RAM, and the BIOS cannot handle it, or is there a problem with the 6400 RAM that I bought which I was told was backward compatible?
And why can windows function well with the extra RAM - well 3GB of it anyway - and the BIOS cannot (or windows cannot until the drivers are installed!)?

Any Comments?

 

Hi brian_s, sorry for my poor english,
I think your (and also my) problem are related to intel chipset 945PM.
Basically you should enable "memory remapping" to achieve your goal, but this chipset seems do not have that capability. Intel 965 does have it, hovewer.

I also have your problem: black screen, unable to go to the boot menu. Also, windows 7 startup screen do not show the classic animated logo, instead i see the yellow "setup" bars. I think this is due to conflict between the video graphics adapter memory and the "new" added memory.

 

Hi,
I'm having a similar problem like brian_s, and endymion70.

I have a Vaio VGN-AR31S, with trial boot: Win XP, Win 7 x64 ultimate, and Ubuntu 10.10 x64. All these OS are managing with Burg (a new version of Grub).

A had any problem, and all these OS works flawlessly with my 2Gb original RAM.

Wen i upgraded with 4gb Kingston HyperX PC2-5300 CL4 my headache begin.

Suddenly Burg dessapears, (Nvidia doesn't shows Burg menu) i remember the order so i can select any OS with the arrows keys. Also i can do it with a bootable SuperGrubDisk.

- When i select Win7 any problem at all. But only recognize 3Gb.
- When i select Win XP , the main screen appears but then only shows a black screen (some problem with graphic card).
- When i select Ubuntu i can't enter in the graphic mode. Only text mode. If i chose recovery funtion with limited graphic mode, it works but in a very low screen resolution.

If i install the 2G orginal RAM all works again perfectly.

It seems a conflict between the memory and the graphic card.

So, any idea or suggestion?

Thank you

Regards