Dell Dimension 1100 technical specifications:
Type 333- and 400-MHz DDR SDRAM
NOTE: DDR333 and DDR400 memory runs at 266MHz when configured with Celeron 400MHz FSB processors
NOTE: DDR333 memory runs at 320MHz when configured with Pentium 4 800MHz FSB processors
The general rule for DDR RAM is that all installed RAM modules will operate at the speed of the slowest installed RAM module. For more information, read everything in the "Manufacturer Specifications - Dell Dimension 1100" section in the following link:
Your will have a performance improvement in XP simply because your total RAM is increased. You will have further improvement if you install matched pairs to enable dual channel mode
Get at least one 512MB module of DDR400 (PC3200) RAM. Get two modules of 512MB or larger for dual channel mode.
i have a DELL Dimension 1100,pentium 4,and it has a 256MB ram, i guess its a PC 3200,im planning to buy a 512MB ram but in the owner's manual it is stated that if i install a mixed pair of memory, the modules will function at the slowest speed install.so if i was to install a 512 ram and the original 256 ram i will be having 768MB ram,but will my PC's performance follow the 256MB ram,and whats the diferrence between installing a the memory modules closest to the processor and futher away from the processor?