ate) Refers to an SDRAM memory chip that increases performance by doubling the effective data rate of the frontside bus.
) A type of DRAM memory chip that has been widely used since the latter part of the 1990s. SDRAM chips eliminate wait states because they are fast enough to be synchronized with the CPU's clock. The chip is divided into two cell blocks, and data are interleaved between the two. While a bit in one block is accessed, a bit in the other is prepared for access. This allows SDRAM to burst subsequent, contiguous characters at a much faster rate than the first character.
DDR and DDR2
Double Data Rate SDRAM (DDR) doubles transfer rates by transferring data on both the rising and falling edges of the clock. DDR uses additional power and ground lines and is packaged on a 184-pin DIMM module rather than the 168-pin DIMM used by the first SDRAM chips. Laptops use 200-pin SODIMM modules.
DDR2 chips increase data rates using various techniques such as on-die termination, which places the terminating transistors that eliminate excess signal noise on the chip itself. DDR2 modules require 240-pin DIMM slots, and although they are the same length as DDR, they are keyed differently and will not fit into the DDR slot.
Dual Channel DDR and DDR2
Chipsets on the motherboard may support two independent memory controllers, which allow access to two memory modules simultaneously (upstream data on one 64-bit channel; downstream data on the other). Channels can be configured as two 64-bit or one 128-bit. Modules must be installed in matched pairs unless the chipset has an option for mismatched modules. See memory module
Memory Module DIMM
Type Speed Symbol Bandwidth Module
DDR2 800MHz PC2-6400 12.8 GB/sec 240-pin
DDR2 667MHz PC2-5300 10.6 GB/sec 240-pin
DDR2 533MHz PC2-4200 8.5 GB/sec 240-pin
DDR2 400MHz PC2-3200 6.4 GB/sec 240-pin
DDR 566MHz PC-4500 9.0 GB/sec 184-pin
DDR 533MHz PC-4200 8.4 GB/sec 184-pin
DDR 500MHz PC-4000 8.0 GB/sec 184-pin
DDR 466MHz PC-3700 7.4 GB/sec 184-pin
DDR 433MHz PC-3500 7.0 GB/sec 184-pin
DDR 400MHz PC-3200 6.4 GB/sec 184-pin
DDR 366MHz PC-3000 5.8 GB/sec 184-pin
DDR 333MHz PC-2700 5.3 GB/sec 184-pin
DDR 266MHz PC-2100 4.2 GB/sec 184-pin
DDR 200MHz PC-1600 3.2 GB/sec 184-pin
SDRAM 133MHz 1.1 GB/sec 168-pin
SDRAM 100MHz 800 MB/sec 168-pin
It's late... whatever... but I still have to post here... I could get in info that others haven't posted yet... lol... I'm trying here...