Look to your PC's motherboard to determine the particular form of upgrade RAM you should use to produce a configuration appropriate for your system. Know your motherboard's requirements before you buy RAM, and you'll do fine. Purchase blindly, and you could prevent your system from booting, cause constant memory-error messages, or (in the worst case) even destroy the RAM itself.

+Secure Digital Memory
Developed by Matsushita (Panasonic), Sandisk and Toshiba specifically for small hand held devices like, PDA’s, Digital cameras; Hand held PC’s, cell phones, MP3 players and some GPS portable units. Secure digital cards or SD card for short, is a derivative of the now widely used Multi media (MM) cards. The SD’s data transfer rate is up to 10MB/sec, which is four times faster than the MM cards. It also has a sliding switch on its side, like 1.44 floppy disks, to protect its data from accidental deletion. The outstanding feature of SD cards is that, it is in compliance with SDMI or Secure Digital Music Initiative. This feature of the card will not allow for example, a copyrighted music to be downloaded from any source. Almost all electronic manufacturers are coming up with products, which support the SD cards hoping this would be the next big thing in memory cards. Products, which support SD cards, are almost backward compatible with MM Cards but not the other way around.

+Rambus
RIMMs, from Rambus Inc., Mountain View, CA., use a very different approach than Cached DRAM and Enhanced DRAM to increase speed. By concentrating on improvements to the memory bus, RDRAM is able to combine IC level improvements with a bus architecture that is optimized for the new DRAM design. Each Rambus chip has an onboard controller circuit that handles address decoding and page cache management. By combining these chips with the new Rambus Channel, byte-wide multiplexed bus, a memory system with a low access time and an extremely fast data transfer rate is created. It is important to note that this is a system level improvement, not just a component upgrade. The Direct Rambus™ high-speed memory interface enables the highest DRAM performance - 1.6Gb/sec/DRAM device.  The technology spans multiple DRAM generations - from 32Mb to 1Gb densities.

The Direct Rambus RIMM Module is a next-generation high-performance plug-in memory module for PC main memory. Developed in conjunction with Intel Corporation, Direct Rambus technology has the performance/cost ratio demanded by the high clock-rate microprocessors used in mainstream PCs starting to ship in 1999.

The RIMM module conforms to the standard DIMM form factor, but it is not pin-compatible. Its architecture is based on the electrical requirements of the Direct Rambus Channel, a high-speed bus operating at a clock rate of 400MHz, which enables a data rate of 800MHz (data is clocked on both clock edges). A two byte-wide data channel is used resulting in a peak data transfer rate of 1.6 GBytes per second. The bus uses transmission line characteristics to maintain high signal integrity.   Some content © Copyright 1998 by Rambus Inc.

+PC-150
The new PC-150 SDRAM modules use the normal 168pin DIMM format and can support 150Mhz FSB. This is indeed great news for all who plan to get their systems running over 150Mhz FSB, by over clocking, when their PC-133 SDRAM can achieve it. If a PC-133 can achieve 150Mhz+ that means this new PC-150 SDRAM can achieve 170Mhz+

+Double Data Rate (DDR)
DDR is the next mainstream standard for high-performance synchronous DRAMs. Transmitting two bits per clock period effectively doubles the data bandwidth while maintaining manageable clock rates. Component speed -7 at 133MHz allows operation at CAS-Latency 2 (CL=2) resulting in the PC266 rating, and speed -8 allows 100MHz operation at CL=2 resulting in the PC200 rating

+BGA
A new and innovative small BGA (Ball Grid Array) - A chip package having solder balls on the underside for mounting. BGA allows for a reduction in die package size, better heat dissipation, and greater module densities.