Upgrading RAM of an old laptop - some questions re: module compatibilty and dual channel support

This is about an old laptop of mine, bought in 2005, an Asus A6R. Crucial.com memory upgrade specs: Computer memory upgrades for ASUS A6R Laptop/Notebook from Crucial.com

The laptop's motherboard supports up to DDR2-533 speeds but DDR2-800 RAM sticks will still work, albeit at DDR2-533 speeds.

I have come across a 1GB module of a Samsung DDR2-800 (PC2-6400 (400 MHz)) RAM and tried installing it alongside the existing 1GB Kingston module of DDR2-533 RAM (PC2-4300 (266 MHz)).

I should have 2GB of total RAM but Windows XP reports my total RAM as 896 MB (128 MB as shared memory). My BIOS also reports the same as Windows. CPU-Z detects all of the total memory that I have installed (see CPU-Z details below), though.

I tried swapping the places of the RAM modules in the slots, but the issue persists. I also tried installing the DDR2-800 Samsung module by itself (2nd slot is blank) - Windows loads and works fine with this RAM module.

Also - weird: If I install the 1GB DDR2-800 Samsung RAM by itself , the BIOS and Windows reports 960 MB total of available memory, much larger than the 896 MB if both are installed. Does anyone know the reason for this?

According to the Crucial.com link, I thought that this laptop should have a maximum memory of 2GB(2048MB) and that 1GB memory sticks are supported. Is there any workaround that I can do to make Windows detect all of the memory I have installed? Anything that I might have installed or configured incorrectly?

I might be buying another 1GB DDR2-800 RAM stick (and just test it before buying) to go with this Samsung DDR2-800, to hopefully, get it up to 2GB. (I can't find any DDR2-533 RAM on local stores, anymore)

Dual channel questions: Is there a way to verify if my laptop's motherboard supports Dual channel? How do I check this? Would two 1 GB DDR2-800 RAM sticks enable Dual Channel for my laptop?


CPU-Z details (1 GB DDR2-533 RAM stick installed alongside a 1 GB DDR2-800 RAM stick):

 

I would purchase two matching 1gig sticks of ram for it. You will get better speeds from a matched set. Obviously there is some kind of incompatibility going on here. You can purchase the specified ram from several places over the web. Newegg has a selection of it. Newegg.com - DDR2-533

 

Would it be fine if I purchase another 1 GB DDR2-800 RAM stick instead to match with the other 1GB DDR2-800 RAM stick I already have? Will if affect performance (compared to two 1 GB DDR2-533 RAM sticks)?. I can't find any local shops that sell DDR2-533 RAM and shipment charges will make buying from Newegg (I'm not in the US) more expensive.

 

Do you have the latest BIOS, XP SP3, chipset drivers and BIOS settings properly configured?

If Windows is only showing 896MB RAM, that is all it is using.

I too highly recommend two matched sticks/modules - won't matter if you match the 533 or the 800MHz one.


Good luck.

 

Yep, latest BIOS drivers from ASUS' website. I don't know which one's the chipset driver in the ASUS website for my laptop, so my chipset driver may or may not be the latest: ASUSTeK Computer Inc.-Support-

I've scoured the BIOS settings for possible tweaks to make it use 2 GB but have been unsuccessful.

Also, by the way, I am now using Windows 7, and it is fully updated (currently SP1). When I tested the RAM back when this laptop was still XP, XP was also fully updated to SP3. My Windows Update is always set to auto-update.

If it matters, I'm using AMD-provided drivers (the Vista version) for my ATI Xpress 200M video card and Windows-update provided drivers for pretty much the rest of the computer's hardware: sound card, network adapter, etc.

I see. I guess I'll match another 1GB DDR2-800 RAM stick then.


Can anyone advice me if I'll have any luck enabling dual channel with my setup?

 

There won't be a difference as the DDR2-800 will be forced to run at the same speed as the DDR2-533 that's already in you laptop. Also I doubt that you're laptop can run the at 800MHz. If your laptop is a pentium M based laptop than whatever ram you put will run at 533. If it's Core Duo or first generation Core 2 Duo it will run at 533 with a 533 ram (or one 533 module plus a 667 or 800 module) and run at 667 with a 667 ram (or one 667 module + a 800 module).

 

From most of what I've read on your model, Dual Channel is not supported.

Don't rely on the Windows Update drivers: see if a better match (even if it's an older driver) is available for your hardware directly from Intel, AMD, etc.

I would also install device/model specific drivers for the Sound, Card Reader, etc. too. You just don't know which driver has the proper .inf file to 'enable' a feature or two.

Good luck.

 

Yeah, I already know that DDR2-800 RAM will run at DDR2-533 speeds on my laptop. About the performance, I was talking about Dual Channel or other performance improving methods when I put two RAM sticks in my laptop, instead of one (aside from the performance from increasing the laptop's total memory).

I see. No luck on the dual channel, then. But will there be performance enhancements on two 1 GB RAM sticks, compared to one 2 GB RAM and a 1GB RAM stick? The price difference between 1 GB and 2 GB RAM is minimal. (I have been able to put one 2 GB DDR2-800 RAM in the laptop before and it worked fine, but when I add a 1GB DDR2-533, Windows still detects only 2 GB of RAM.)

Edit: I also would like to ask if there is a performance impact if I buy another 2 GB DDR2-800 RAM to match with the existing 1 GB RAM I have, compared to matching it to another 1 GB DDR2-RAM? Why are matching 1GB-1GB sticks advisable?

 

I would like to add that: Someone has given me a 2 GB DDR2-800 RAM stick to add to my existing 1 GB DDR2-800 RAM, bringing my laptop's total memory to 3 GB (detected by Windows 7). So, it looks like I'm gonna be sticking with this one and not be buying an additional 1 GB RAM anymore.

Is there a performance difference between two matching 1 GB RAM sticks, compared to a 1 GB RAM stick installed with a 2 GB RAM stick (aside from the bigger RAM of the 3 GB combo)?

 

There is, assuming your notebook supports dual channel, but since tilleroftheearth says that it doesn't, then no, there probably isn't. As well, even with dual channel, the difference with most modern systems is pretty much unnoticeable except in benchmarks.