A8Js sees 2 Gig Stick but not 2 2 Gig sticks

OK, so I was happy that my notebook recognized the 2048 stick of ram. Thought I would go ahead and get another and put the 1 gig stick originally in the puter in my son's puter that only has 512 of ram.

With both sticks in BIOS will only see three gigs (actually 2944). Both sticks work by themselves. Any ideas? I think this will call for a BIOS update.

FYI - It does run in duel channel interlaced with both sticks in.

 

Pretty sure the chipset isn't going to let you access the full 4GB of RAM; you'd need a Santa Rosa-based machine I think.

 

Yeah chipset limitation or needs a bios update.

 

Two things:
1) lack of address space on a 32 bit operating system
2) cheap motherboards that only support 32-bit addressing, even though they will accept 4GB. http://www.interact-sw.co.uk/iangblog/2005/08/05/is3gbenough

Chipset has nothing to do with it. I went through quite a bit of hassle to find a desktop that would see 4GB+ of RAM.

 

you will need a 64 bit os.


should not need a bios update.

 

@ both noahsark and stmar what your bios reports has NOTHING to do with your OS, even still a 32bit OS can se ~3.5gb max.

 

I never said anything about the bios. The link I gave explains two of the very common reasons that people can't see all 4GB of RAM in their OS, even though it all may post just fine. Yes, you can see more than 3 GB, because your system doesn't have 1 GB of I/O to map, just 500MB. You would see 3.75GB if there were only 256MB of I/O to map.

A 64 bit OS WON'T fix the problem IF the motherboard doesn't support ADDRESSING more than 4GB of memory. I had exactly this problem with workstation we got from Dell. The motherboard accepted 4GB RAM just fine, but neither 64 bit windows or 64 bit linux could find all the RAM, even though it all posted. Why? Because the guy who bought the machine didn't check to make sure that the motherboard Dell used would ADDRESS more than 4 GB memory.

Big difference between accepting 4GB of RAM and ADDRESSING more than 4 GB of memory. To have 4 GB of RAM available for the OS requires that the MOTHERBOARD can address at least 4.5, maybe 5 GB of memory space. Recall that you need to address more than 4 GB because you need to leave memory mapping space for I/O, as the link points out, in addition to mapping all the physical RAM.

 

Let me start by saying that I was very aware that a 32 bit OS was going to have problems with 4GB of RAM. What I wasn't expecting was for my computer designed around a 64 bit addressing processor to have problems with seeing all 4GB. I made some assumptions (yea, I lnow what they say about assumptions) based on the fact that at the time I bought the machine that Asus was offering an upgrade to Vista 64.

I know the chipset was designed to address 4GB so I am wondering if a BIOS update will fix this (If Asus ever decided to address this)?

noasark - Thanks for the link. It is somewhat enlightening and I will do more research on this.

THis is the first personal machine that I have owned that I didn't build myself since the early 1980's (yea, I'm probably old compared to most on this board). This is also the first laptop I've used as my personal machine. I've become hooked on the portability of it but I continue to be disapointed with the limitations of a laptop. I am also dispointed that anyone would design such limitations into any machine. What would be the point of 64 bit computing without the advantages of access to greater amounts of RAM? What was the point of me waiting for the Core 2 processors if there is no real advantage? I must be getting lazy, I pay too much attention to marketing hype instead of doing the heavy duty research to find out what is really under the hood.

I have always respected Asus motherboards for being the first to push the limits. I guess that doesn't hold true for there notebooks.

 

Don't blame Asus for that; the laptop is still using the Napa platform, which uses Intel's older chipset. When Merom Core 2 Duo CPU's were released, they were shoehorned into the existing Napa platform.

Santa Rosa is the platform you're looking for.

 

zadillo - I will say it one more time, The chipset is designed to see 4GB. I put the 2 sticks in my son's $500 Compaq with the same chipset and the hardware detects all 4GB.

 

Yep, according to Intel the chipset should be able to address 4gb RAM... I remember seeing some stores selling the A8Js already with 4gb. I've also asked Asus support about this issue, and they told me that it wouldn't be problematic. Do tou have the latest bios (2.11)?

 

Mark, as Ian points out in the link, it's not that rare for motherboards to accept 4GB of RAM but be unable to address all of it. Most boards don't even address this. I checked in manuals for the many boards I have bought, and none of them talk about how much memroy they can address. A bios flash won't fix the problem if the top 4 address bits of the processor aren't actually connected up to anything.

You need to start emailing/calling asus, or better still, your vendor, and ask them if the motherboard can address more than 4 GB of RAM. They will tell you 'oh, sure, it accepts 4 GB of RAM' (this is what happened when I called dell). But, you need to be persistent and patient because odds are most people you talk to won't understand the difference between accepting and addressing all that RAM. You will probably have to get them to hook you up with some engineers.

 

nickie's post came up in the middle of my last one. The link s/he gives shows that the 945 chipset addresses up to 4GB of memory. You are SOL, Mark. The board AND chipset have to address MORE than 4GB of memory space in order to utilize 4GB of RAM AND map all the I/O.

 

nickie - Yes it is the 2.11 chipset.