thinkpad380xd - laptop batteries memory

What is Buffered Memory? Buffered memory uses a Buffer chip to boost the clock signal sent across the memory module so that the clock signal is seen as a clean, sharp signal across the entire module. It eliminates chances of memory errors in data sent or retrieved from memory. It is commonly used in larger capacity Fast Page Mode or EDO modules. Buffered modules have a different keyway in the contact edge and can only be used when the board supports Buffered modules. Unlike Registered modules, it is not interchangeable with Unbuffered modules. Can I mix different speeds? PC600, PC700, and PC800 are three different speeds of memory once available for RDRAM (Rambus dynamic random access memory) modules. Of the three, PC800 modules are the fastest, and PC600 modules are the slowest. (PC600 and PC700 are no longer being produced by any manufacturer)

what is Rambus Memory? Rambus is a chip to chip interface design that is system wide, allowing up to 800 MHz transfer rates. It allows data transfer through a simplified bus that operates in a high frequency range. Rambus uses a low voltage signal swing with data transfer on both edges of a synchronizing clock pulse. The Intel Pentium IV CPU is designed to take full advantage of this new, extremely fast memory design. What is DDR Memory? DDR memory, or Double Data Rate memory, is an evolutionary new memory technology that doubles the data through put to the processor, or CPU. It is an evolution of SDRAM, which leverages the existing production and environment to provide higher PC performance. What is meant by Registered memory? "Registered" is a means of "Buffering" the memory in SDRAM. This means that the clock signal is boosted across the entire array of memory chips so that the computer sees a clean sharp clock signal instead of a weakening clock signal as it progresses along the length of the memory path. Registered memory must be supported by the system board and cannot be mixed with "Unbuffered" modules. You must have only Registered memory to use Registered memory.

EDO DRAM. Extended Data Out DRAM EDO speeds are measured in nanoseconds. You can buy EDO as fast as 50ns for your personal computer main memory (you may see faster EDO DRAM on some graphics cards. EDO memory is commonly available as 72-pin SIMMs). FPM DRAM. Fast Page Mode DRAM Fast-page mode is becoming increasingly scarce, but, unless you''re running a very early system (430NX chipset or earlier) or a 486 system, you probably don''t want to get DRAM. Fast-page mode memory comes in SIMMs. RDRAM is shipped in RIMMs (RAMBUS inline memory modules). Future systems using the Intel 820 chipset and the upcoming 600MHz plus Pentium IIIs will use RAMBUS memory, but they aren''t out as of this writing. Way back in the dark ages of the PC architecture, I once owned an original Compaq portable. While the Compaq supported a whopping 640KB of RAM, it only came with 256KB. I upgraded my Compaq myself with an additional 384KB of memory by carefully inserting 27 individual 16KB RAM chips. The hunger for memory has steadily increased since then; 64MB is no longer unusual. Upgrading memory is easier, too; you no longer must painfully insert individual RAM chips.