This is a problem that doesn’t have a good answer.

Over the past 20 months, I have been asked a few times, to upgrade the RAM on a laptop.

The age of the laptops can vary from 1 to 6 years old… Yet I often find it difficult to get RAM that will work correctly (unless I do a lot of forum trawling, looking to see if laptop X will work with RAM Y).

A case in point is a Compaq laptop (maybe 3 years old)… It had a double sided DDR SODIMM ram card (PC2100, 266MHz)… nothing extraordinary.

I happened to have a single-sided 128Mb PC2100. I understand that the days of single-sided and double-sided RAM cards died with the older SDRAM standard… But I could be wrong.

I try the 128Mb RAM, and it works great.

The customer wants 512Mb RAM (I can’t find any 256MB RAM), so I get a used 512Mb SODIMM (double sided, PC2100). But when I try it, it just doesn’t work! (no other RAM: black screen, with other RAM: the 512 is not detected). I take it back to the supplier, and it tests OK.

As luck would have it, I’m looking at upgrading another laptop, and the memory works in that one. Phew!

I can only think of one main reason (and maybe a few related reasons) why the RAM didn’t work: the laptop is designed with a maximum allowed RAM (or RAM socket) size… which seems crazy to me… why artificially limit the expansion capabilities of a laptop?

And there have been countless times when I get what should be compatible RAM, and it doesn’t work (but works in a different laptop.

I’ve never had this much difficulty with ordinary PCs… so why are laptops so difficult?