This is a real silly question about DDR SDRAM !!

[leeland]

looking at some new boards and an epox board i was reviewing says that is accepts PC1600 and PC2100 can someone please tell me the difference of these two types of RAM...i don't want to sound like a fool with this one but i am lost

thanks
lee

 

[BlueScreenVW]

This simply refers to bandwidth. PC2100 is clocked at 133 MHz, and accordingly has twice the theoretical throughput of single data rate PC133, which is 1066 MB/s. So, the bandwidth of PC2100 is up to 2x1066 = 2133 MB/s. In the same way PC1600 is clocked at 100 MHz and has 2x800 = 1600 MB/s bandwidth.

 

[AndyHui]

PC100 DDR = PC1600.
PC133 DDR = PC2100.

 

[eklass]

Taken from Mushkin's website:



<< DDR (double data rate) SDRAM is the latest evolution in random access memory (RAM) technology. All SDRAM operates on a system frequency or &quot;bus&quot; speed measured in mega hertz (MHz). Traditional SDRAM used only the rising edge of the clock cycle to transfer data. The new DDR SDRAM transferrs data on both the rising and falling edge of the clock. PC2400 is not an actual JEDEC specification but rather a guarantee that the memory will run beyond its specification. PC2400 DDR SDRAM is designed to run stably when overclocked to 150MHz (300MHz DDR). PC2400 describes the memory's transfer rate of 2400 MB/sec (2.4 GB/sec) on a 64-bit bus rather than its MHz speed. >>




<< PC2400 DDR uses DDR-266a chips. The DDR-266a chips are the fastest bin rated for CAS2 operation at 266MHz. These modules are programed for CAS 2.5-3-3 operation at 300MHz via the serial presence detect (SPD) EEPROM. PC2400 DDR is designed for use with CPUs which run on a 133MHz FSB (266MHz DDR) but which are known to run stably when overclocked to a 150MHz (300MHz DDR) FSB. Although the increase in bus speed from 266MHz to 300MHz does translate to an increase in performance, a much larger gain comes from using DDR which runs at lower latencies. If the fastest possible performance from your system is important to you, we recommend using our High Performance DDR with the lower latencies over using PC2400 which runs at a faster bus frequency but with higher latencies. >>



This is of course about PC2400 DDR SDRAM. You would want to throw this in your board if you think you needed the higher abilites (just as you might want to try 'PC150' SDRAM if the PC133 SDRAM was limiting your overclocking abilities.

 

[eklass]

duplicate post... sorry

 

[leeland]

man thanks guys for the info, that web site hit it right on the head, really appreciate the reply


lee