533MHz and 667MHz Memory

I am on the verge of getting a Dell notebook (either the E1705, D820, or M1210) and I have a question about the RAM. If the notebook comes with 512MB x 1 memory that is 533MHz, can I put a 667MHz 1GB stick of RAM in the unused slot? As in can the memory in the two slots be differing without any detrimental effects (as long as both speeds are suported by the motherboard)? Obviously I am not trying to go for dual channel or whatever, but rather the cheapest way to get the most RAM. I would prefer to avoid teh ripoff prices that Dell (and every oteher computer manuf acturer) charges for memory and instead buy RAM off newegg.
Thanks for the help/

 

Its best to have both sticks be the same brand and speed. Besides the 667mhz stick will just downclock to the other sticks speed of 533. Go same brand same speed and dual channel

 

Yes, If you wan't one GB of 667 then buy it after market. Save the 512MB 533mhz stick as a backup and if you ever need to get your dell fixed put that stick beack in. Then order 1GB DDR667mhz from newegg or something... Dells RAM upgrades are insane! Tons of $!

 

yes, dell's ram options are ridiculous and I'm pretty sure they're value ram.
whenever you have 2 different speeds, the higher one will always downgrade to match the slower speed, so it would be a waste to get higher one unless you plan to replace all the ram in your comp. you can convert from good to bad, but not from bad to good.

 

I am thinking of the same thing.

If i do upgrade my notebook with a 1gb 667MHz ram in addition to the 512mb 533MHz that came with my E1505, will there be any problems?

and when you guys say the the 667 will downclock to 533, does that mean that the 667 will permenently be 533 or will it go back up once i get another gig of 667?

 

if will go back up once you have both sticks that are 667