Upgrading memory - size matching

[DarwinIT]

I want to add more memory to a computer which has two 512 meg chunks. There are 4 slots. Can I add two 1-gig sticks in those slots or do all four have to be the same size.

 

[kmcferrin]

It depends on the computer. Post what hardware you're using and we'll see.

Generally, if you have four slots there's a good chance that you'll have a dual channel memory controller. What that means is that two slots go to channel 0, and two slots to channel 1. The modules must be the same within a single channel, but can be different across channels. Usually.

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[DarwinIT]

Thanks!!

acer ast180-ua381b

I believe I need DDR2 SDRAM 800 mhz - PC-6400 modules.

 

[Sympology]

Look up the Kingston memory advisor and do a scan (if running Windows).

Save you a lot of hassle.

Robert Wilensky:
We've all heard that a million monkeys banging on a million typewriters will eventually reproduce the entire works of Shakespeare. Now, thanks to the Internet, we know this is not true.

 

[goombawaho]

Crucial memory advisor says:

Max of 1GB per slot/Total of 4GB for all slots
240-pin DIMM
DDR2 PC2-5300 • CL=5 • Unbuffered • NON-ECC • DDR2-667 • 1.8V

 

[DarwinIT]

Unfortunately we ordered 800 MHZ - PC2-6400
The spec for that model says it comes equiped with 533MHZ - PC2-4200

Does that mean the 800mhz memory won't work at all?
Does that mean that the existing memory would have to be removed to use this memory?
Can you damage a computer by putting the wrong memory in?
Thanks so much!!!

 

[kmcferrin]

Faster memory will generally work fine in systems that require slower memory of the same design. It will just downgrade to the slower speed. For example, if your system requires DDR2 800 MHz RAM and you install DDR2 1066 MHz RAM, it will work at the DDR2 800 MHz speed. However, if your PC requried DDR 400 MHz and you tried to install DDR2 800 MHz it wouldn't work (mainly because it won't fit in the slot, but the memory technology is different too).

This is generally the case, but of course there may be an exception when dealing with a finicky system.

________________________________________
CompTIA A+, Network+, Server+, Security+
MCTS:Windows 7
MCTS:Hyper-V
MCTS:System Center Virtual Machine Manager
MCSE:Security 2003
MCITP:Enterprise Administrator