DDR Memory Bandwidth
The calculations below illustrate how the peak bandwidth for DDR memory modules is calculated.
Peak Bandwidth = (Memory Bus Width) x (Data Rate)
where Data Rate = (Memory Bus Speed x Operations/Clock Cycle)
- Each DIMM module is 64 bits wide, or 8 Bytes wide (each byte = 8 bits).
- Peak bandwidth for PC1600 DIMMs
- (8 Bytes) x (200 MHz Data Rate) = 1,600 MB/second
or 1.6 GB/second.
- Peak bandwidth for PC2100 DIMMs
- (8 Bytes) x (266 MHz Data Rate) = 2,128 MB/second
which is
rounded to 2,100 MB/second or 2.1 GB/second.
- Peak bandwidth for PC2700 DIMMs
- (8 Bytes) x (333 MHz Data Rate) = 2,664 MB/second
or 2.7 GB/second.
- Peak bandwidth for PC3200 DIMMs
- (8 Bytes) x (400 MHz Data Rate) = 3,200 MB/second
or 3.2 GB/second.
| Bandwidth Summary |
PC100
SDRAM |
PC133
SDRAM |
PC1600
DDR |
PC2100
DDR |
PC2700
DDR |
PC3200
DDR |
| 800 MB/s |
1.1 GB/s |
1.6 GB/s |
2.1 GB/s |
2.7 GB/s |
3.2 GB/s |
|
