DDR2 PC2-4200, DDR2 PC2-5300, DDR2 PC2-6400, and DDR2 PC2-8000
In DDR2 modules, the numbers that come after the "PC2" refer to the total bandwidth of the module. For this type of memory, a higher number represents faster memory, or more bandwidth. Occasionally DDR2 is referred to as a "Friendly name" like "DDR2-533" or "DDR2-667". When written this way, the numbers after "DDR2" refer to the data transfer rate per second (/s) of the components. DDR2 is not backward-compatible with DDR.
Friendly Name Industry Name Peak Transfer Rate Data Transfers/Second (in Millions) DDR2-400 PC2-3200 3200 MB/s 400 DDR2-533 PC2-4200 4266 MB/s 533 DDR2-667 PC2-5300 5333 MB/s 667 DDR2-800 PC2-6400 6400 MB/s 800 DDR2-1066 PC2-8500 8533 MB/s 1066
DDR2 PC2-4200 (commonly referred to as DDR2-533) memory is DDR2 designed for use in systems with a 266MHz front-side bus (providing a 533MT/s data transfer rate). The "4200" refers to the module's bandwidth (the maximum amount of data it can transfer each second), which is 4200MB/s, or 4.2GB/s.
DDR2 PC2-5300 (commonly referred to as DDR2-667) memory is DDR2 designed for use in systems with a 333MHz front-side bus (providing a 667MT/s data transfer rate). The "5300" refers to the module's bandwidth (the maximum amount of data it can transfer each second), which is 5300MB/s, or 5.3GB/s.
DDR2 PC2-6400 (commonly referred to as DDR2-800) memory is DDR2 designed for use in systems with a 400MHz front-side bus (providing an 800MT/s data transfer rate). The "6400" refers to the module's bandwidth (the maximum amount of data it can transfer each second), which is 6400MB/s, or 6.4GB/s.
DDR2 PC2-8000 (commonly referred to as DDR2-1000) memory is DDR2 providing a 1,000MT/s data transfer rate). The "8000" refers to the module's bandwidth (the maximum amount of data it can transfer each second), which is 8000MB/s, or 8GB/s.