Ok to combine 256Mb and 512Mb sticks?

Hi

Apologies if this has been covered before - I had a good trawl through previous posts and couldn't find the info I needed. Anyway, I hope someone will be able to help me

My question:

I have an ABit BD7-II motherboard with 2 x 256Mb DDR2700 Samsung Original sticks on board. I want to increase my RAM to 768Mb or preferably 1gig but is it possible to do this and utilise my existing memory? The BD7-II has 3 DIMM slots and the manual says that DIMM2 and DIMM3 are 'sharing' (whatever that means). Maximum memory is quoted as being 2Gb.

Options as I see them are:

1) Buy another 256Mb stick (The same brand, Samsung Original - as it's still available to me). This would give me 768Mb and seems the safest choice (the choice most likely to work ok, aside from replacing the whole lot with 2 x 512MB sticks which isn't going to happen).

2) Buy a 512Mb stick of the Samsung original memory and put it in the 3rd slot alongside the 2 existing 256Mb sticks. This is the option I really want to take but am unsure of the compatibility issues with mixing 256Mb and 512Mb DIMMS. Does anyone have experience of mixing memory like this? I'd be particularly interested to hear from anyone with a BD7 or BD7-II with mixed memory.

Thanks in advance for your comments.

Don't think there should be a problem, I've mixed sizes like that on an Abit KR7A & an Epox 8KHA+ before. Never had any problems with either

i think that is becuz the mobo wont be able to supply enuff voltage. the higher that operating frequency the higher the voltage it requires usually. thats y mobo manufacturers say 2 sticks of DDR 3200 and 3 sticks of DDR 2700 or stuff like that.

Actually it's not the Voltage but the Amps needed by those large capacity DDR sticks filling up all DIMM slots. I've seen the first mobo's with a molex power connector next to de DIMM slots just for that extra juice...

Thanks for the replies

My 2 existing sticks are PC2700 and the BD7-II motherboard manual says that it supports PC1600 and PC2100 (so, not even the PC2700 is officially supported). I wonder if it will be able to take an extra PC2700 stick. Hmm.....

I also would really like to know what the BD7-II manual means when it says that my 2nd and 3rd memory slots are "sharing". The exact quote from the manual is:

"Supports three 184-pin DDR DIMM module (DIMM2 and DIMM3 are sharing) up to 2Gb Max."

If anyone can shed some light on this i'd be very grateful. Cheers.