It means that it runs at 400 MHz (That is 400 million data transfers per second).
Now for the PC3200, this means that the peak transfer rate delivered is 3200 MB/s
Click the following link for more details
http://en.wikipedia.org/wiki/DDR_SDRAM
No. DDR RAM cannot be used to replace or upgrade a PC133 module.
DDR400 RAM contains better hardware and faster processing speeds. The DDR400 RAM is able to perform tasks at a significantly faster rate than normal RAMs.
No, pc133 is SD ram and Pc3200 is DDR ram. They are not compatible with each other.
DDR
No it cannot It has an nvidia chipset 6150 That board is generally a winfast foxconn board or sometimes a biostar emachines modified version and as such is a 939 board ddr memory NOT ddr2 It will take up to a pc3200 (ddr400) memory
PC3200 Ram can be purchased from many stores and online retailers. One can buy it from Best Buy, eBay, Amazon and TigerDirect. It costs between $15 and $30.
PC3200 is a kind of memory for computers. It is compatible with a computer if the BUS speed of the RAM module is 400MHZ or megahertz. The memory chip will have PC3200 written on it for easy identification.
PC6400
Your motherboard might be able to 'clock back' the DDR400 to DDR333. This means that the DDR400 ram will reduce it's clock speed to DDR333 to be compatible. Not all motherboards support this though.
DDR400 was a standard RAM format that actually never happened. It began and ended in 2002. during that year various companies said they would adopt it but then by September it never happened.
It is possible to use pc3200 ddr ram in a PC designed for pc2700 ddr ram, but the pc3200 ram will only run at pc2700. If you want to fully exploit the pc3200 ram then you will have to buy a motherboard that will be able to support a speed equal to pc3200 or greater.
4GB of PC2700 or PC3200