[ The PC Guide | Systems and Components Reference Guide | System Memory | Memory Speed, Access and Timing
]
Memory Bus Speed and Required DRAM Speed
Most modern systems generally require the DRAMs they use to be a certain minimum speed.
The speed required is normally a function of the speed of the memory bus. Faster memory
buses require faster speed DRAMs and in some cases, faster technologies. While it is not
always cut-and-dried what speed is necessary, the table below is a guideline. It is
usually possible to use slower memory in any system if you slow down the memory timing,
but of course we're trying to make our systems run as fast as we can.
Processor Generation |
Memory Bus Speed |
Usual DRAM
Technology |
Usual Required DRAM
Speed (ns) |
First, Second |
4.77-20 |
Conventional |
100-120 |
Third, Fourth |
16-40 |
Conventional, Page Mode, FPM, EDO |
70-100 |
Fifth, Sixth |
50-100 |
FPM, EDO, BEDO, SDRAM |
8-10 (SDRAM) 50-70 (Asynchronous) |
Future |
125+ |
SDRAM, DDR SDRAM, DRDRAM, SLDRAM, Other? |
? |
 Next: System Timing and Wait States
Home - Search
- Topics - Up
|
|
