My roommate had 2 512MB sticks of DDR2 ram in his laptop. His laptop manufacturer's website said the computer could handle 2GB of RAM. He wanted to upgrade, so I told him to get 1 2GB DDR2 stick. From what I've read, it is actually slower than having 2 1GB sticks.

Would there be a noticeable difference from the dual channel if he got another 2GB stick? Would his mobo see the second stick or is it hardware-locked at 2GB?

I understand that 32-bit windowsXP will only allocate ~3GB, and that it's overkill for what he's doing.

12/1/2008 2:55:36 AM

If the manufacturer specifies it can only take 2 GB total, chances are it won't even accept the 2 GB single stick - i.e., it needs 2 x 1 GB.

12/1/2008 9:39:03 AM

^

12/1/2008 9:43:49 AM

Sorry, I guess while editing I removed the part about how I had already installed the 1x2GB stick. Everything technically works, but he says it seems slower, most noticeably in how long it takes to load windows and all the background processes.

That makes my real question: Would adding a second stick of 2GB noticeably increase performance? If so, due to what reason?

12/1/2008 11:00:05 AM

wait...so you currently have a single 2gb stick in there (meaning there's an empty memory slot) and the manufacturer says it will only support 2gb max? that doesn't make sense...i've never seen or heard of a mobo that would work like that - usually, the hardware/bios is designed to only recognize a certain amount in EACH slot, which is the reason for the maximum memory

unless he's running vista and/or something like photoshop, any more than 2gb probably isn't necessary...even if he IS running vista, 2gb is the spot where i wouldn't go any less, but you probably don't need to go any more

and no, 2 sticks should not be faster than 1 if the memory total is all equal...the difference is marginal, but it's there

12/1/2008 11:06:00 AM

Quote :

"Would adding a second stick of 2GB noticeably increase performance? If so, due to what reason?"

http://en.wikipedia.org/wiki/Dual-channel_architecture

not really. it theoretically doubles the amount of data that can be sent from the RAM to the memory controller. it theoretically eliminates a bottleneck in the system, is what it boils down to.

Quote :

"In order to achieve this, first you need a dual channel capable motherboard. Then you need two or more DDR/DDR2 SDRAM memory modules must be installed into matching banks, which are usually color coded on the motherboard. These separate channels allow each memory module access to the memory controller, increasing throughput bandwidth. It is not required that identical modules be used, but this is often recommended for best compatibility for dual channel operation."

12/1/2008 5:08:20 PM