Maximum amount of addressable memory Toshiba a135-s4487

[adramaleck]

Ok guys you are the smartest forum online so I am hoping someone can confirm this for me. I have a toshiba A135-s4487 laptop. It is all stock except for a screen replacement and I upgraded the processor from a t5500 to a t7200 core 2 duo. I am also running windows 7 ultimate x64 RTM. I have the newest BIOS available (v1.9) The specifications say the maximum memory is 4gb. Here is a link to the models home page with detailed specs.

http://www.csd.toshiba.com/cgi-bin/tais/support/jsp/modelContent.jsp?ct=SB&os=&category=&moid=1598562&rpn=PSAD0U&modelFilter=A135-S4487&selCategory=3&selFamily=1073768663

So to make a long story short I bought these memory modules http://www.newegg.com/Product/Product.aspx?Item=N82E16820231135

Now when I installed them inside my bios I show 4096mb installed memory approx as I am not in front of it now. However, at the post screen when the mem test occurs it only shows 3063mb. Searching through forums some people suggested that since the motherboard max memory is 4gb that is the maximum amount of addressable memory and since the motherboard can only address 4gb of memory total it is using 1gb of that for i/o and other things and 3063 is the most the system can use. This is also the amount windows reports when I boot up in terms of usable memory, might say 3064 or 63 not in front of it now.

Is this true? I am good with computers for the most part but I do not have a great understanding of memory addresses and how the whole i/o thing works. I just purchased the intel x25v as well so I plan on reinstalling windows tonight and using that as a boot drive. Is there anything special I can do when installing windows to make it see the whole 4gb? Should I flash the BIOS with the newest version again even tho that is what is currently installed? Any input or help would be greatly appreciated.

 

[RetiredChief]

MotherBoard max for the newer MB's is >4 gigs, Toshiba has limited the Bios to a max of 4 gigs (ie could be the chip set.). The 4 gig limit and the loss of MIMO is a function of the operating system.

I have a toshiba A205 and a A305 and have 4 gigs of ram installed in both (one is Win 7 RC and the other is Win t RTM, both 32 bit). Both show about 3.5 Gigs available to operating system and programs.

 

[adramaleck]

I have a feeling this has something to do with the BIOS and not the OS. Windows ultimate x64 has a maximum memory capacity of 24gb I believe so it must be that my computer is only reporting 3gb to the OS.....correct me if I am wrong.

 

[adramaleck]

windows 7 ultimate sorry

 

[adramaleck]

I think I may have found the problem.

http://blogs.msdn.com/hiltonl/archive/2007/04/13/the-3gb-not-4gb-ram-problem.aspx


So apparently even though toshiba lists the maximum memory as 4gb the laptop cannot address more than ~3. I doubt there is a workaround for this but if anyone happens to know one I am all ears. Failing anything else I suppose I can setup a ramdisk and run my pagefile and some other cache off of it to make me feel like I didnt waste my momey. Open to any ideas....