I'm having problems trying to get a few more months out of an old pc. I've bought some more SD RAM (DIMM). There are 3 slots in the pc. It had - 1x256 and 2x64 chips in. I bought a 512. On replacing one of the 64s with the 512, i was told on bootuo that my ntfs driver is missing. if i swap them round within slots, sometimes i never get any life from it at all. I've tried various configurations but the only one that works is the original one! Is there a rule as to the order and sizes of SD Ram? I seem to remember that one form of ram required twin pairs of ram, but that cant be true as i've got 3 slots... Or any other helpful suggestions?
You had to pair up SIMM's, as they were 32-bit. Have you tried the 512 in another board? It may be faulty. Does the motherboard actually support 512Mb DIMM's?
A lot of the older boards couldn't cope with addressing the modules on 512MB sticks. Best thing todo is see if you can get a BIOS update.
Is the original ram single sided? I have a HP small form factor machine that takes SD and will only take single sided ram - is a bugger!
SDRAM had under gone several changes in the spec when it finally reached the 133 Mhz clock speed it supported. Most systems supporting 66 Mhz SDRAM only had three slots and supported up to 256 MB DIMMs. Machines using 100 Mhz SDRAM were often equipped with four slots and supported up to 512 MB DIMMs. SPD was mandatory with 100 Mhz SDRAM, and I think it was optional on 66 Mhz SDRAM. Boards supporting 133 Mhz SDRAM had three slots and supported 512 MB DIMMs. Boards using registered SDRAM supported more slots at given speeds, but that is server stuff. Putting 133 Mhz or 100 Mhz SDRAM into board that works with 66 Mhz SDRAM is fine as long as the board supports the same chip configurations. The chips configuration is mainly an issue with 256 MB and 512 MB DIMMs. Sometimes the chips will only appear as half there rated capacity and sometimes they simply won't work. Putting 66 Mhz SDRAM onto a system that works with 100 Mhz or 133 Mhz may or may not work. Modules with a SPD chip would reduce the clock speed of the memory bus to 66 Mhz. Putting 100 Mhz SDRAM in 133 Mhz bus systems has worked every time I tired but has correctly reduced the memory bus speed to 100 Mhz. There are likely exceptions to this of course. Note that this reduction in memory bus speed could also change the AGP bus speed. I'd try the 512 MB DIMM in a system sporting a 100 Mhz bus as they're the most flexible when it comes to SDRAM.
