My current RAM is 128 Mb 133MHz SDRAM DIMM. When looking at prices, 2 sticks of 256 Mb are cheaper than 1 stick of the same brand/type 512Mb. I have 2 slots on the motherboard, so 2 x 256 would be more economical, but is there any performance advantage in buying 1 x 512, or is there some other reason for 512 being dearer? Thanks in anticipation.

Buying 2 RAM modules only justificates if you can run them in dual channel, unless not, go for the cheaper 1 module. Some crazy people might say that in case your out of waranty and your RAM fails you will only loose 256mb not the hole 512, but that's crazy!! Think happy thoughts!! ;) GooD LucK! It's nice to be important but it's more important to be nice...

sometimes you find that one item is more than double the price of two with half the memory on. This can be due to that to physically fit twice the memory on the circiut board , the maker has to use more expensive, advanced compact memory chips which are disporportionally more expensive.

SandyR, You should try and buy in incriments of two: 2x256MB 2x512MB 2x1GB I forget why exactly, but I remember hearing once that this is the way it should be done. Hope that helps. - Steven

Your motherboard doesn't support dual channel, that isn't an issue. If you only have 2 memory slots and you already have one stick of 128MB PC133, why would you want to remove this? Buy a 512MB and end up with 640MB. There are some issues to consider. As was mentioned, RAM chips come in different densities. If your memory controller can't handle the higher density chips used on current RAM modules the RAM may not run at all or may show as half the amount. There are some steps to take to assure that this doesn't happen. First of all you need to know the model of your MBoard or if a brand name computer the exact model. If you have the manual for the computer it may give some info on what will and won't work. For instance if the manual states the MBoard can handle a total of 1 GB of PC133 and you have 2 slots, math would say that each slot can hold 512MB. This is true to a degree. The chip used on the module can't be any higher density than allowed. I suggest you go to Crucial.com and use thier mamory configerator. You type in the MBoard or brand then details and crucial will report back what memory they have that is guaranteed to work. This is the safest way to buy memory. Kingston has a similar site. BTW, for normal use 640MB of RAM should be enough.

All 512MB PC133 is high density. Your board MUST have a capacity of 512MB per slot for high density RAM to work. If your total capacity is 512MB & you have 2 slots, your max capacity per slots is 256MB...a 512MB stick will not work & neither will ANY high density RAM. http://support.gateway.com/s/tutorials/Tu_851378.shtml http://www.kingston.com/tools/umg/umg04.asp Asus A7N8X-X 2500+ Sempron @ 2100mhz 10.5 x 200mhz @ 1.80v 512mb PC3200 Ti4200/8X 128mb WDC 60GB

With the money you're about to spend on a memory system that is on its way out the door, you could buy a good motherboard that runs ddr ram. Finding a board that can use your cpu chip should be feasable. Using the rest of the old system will save you some money also. That's just my 2 cents worth. I may be crazy, but I'm not stupid...