a weird RAM question

I have two different older Dell laptops, A and B, both with 512MB ram. I thought the lack of RAM was slowing them down, so I bought 2x1gb sticks and put them both into Laptop B because MaxRam for B is 2GB and MaxRam for A is 1GB, and I figured I could take the 512 stick from B and put it into A to make 1GB.

Then I found out that B's 512 stick is different (DDR400/PC3200) than A's 512 stick (DDR266/PC2100).

If I put the DDR400 stick into the motherboard alongside the DDR266, will it work (at the DDR266 speed), or will it fry/break the mobo that only supports DDR266.

Does that make sense? I'm basically asking whether I can install a RAM stick into a mobo that recommends (demands?) a lower speed and have the memory function and not kill the mobo.

Thanks so helping with this somewhat strange question.

 

The faster ram will run the same speed as the slower one.

It won't "fry/break" your motherboard

 

I have ran into the same issue, I bought 4 gb of Pc 3200 sodimms, so I put two of them into my dell inspiron 8500 and it picked up 2gb, but since it only supported Pc2100, the ram was automativally clocked down to 266mhz from 400

K-TRON