RAM Upgrade for Inspiron 600m - bus speed?

Hi,

I have an old 600m. Originally it came with 512 MB RAM (2 x 256MB), running at 266 MHz (PC2100).

I bought a 1 GB DIMM, PC2700 333MHz to increase the RAM.

I know that if I mix the DIMMS, the speed of the RAM will run at the slower speed, in this case 266 MHz.

But, if I just had the 1GB module installed, shouldn't the RAM run at 333MHz? I looked in the BIOS and it still shows it running only at 266MHz.

My FSB is shown at 400MHz, if that makes any difference.

Thanks.

 

I have a very similar issue with my Dell 8500. What you are running into, is the memory supported by the motherboard. Your cpu does use a 400Mhz bus, but when your system was made, the chipset could only make use of Pc2100 memory which clocked in at 266Mhz. Your chipset and memory timings run at a 3:2 memory interleave, meaning that it takes every three clocks to make the full speed of the processor bus. It is quite fine, and their is nothing to worry about. Your chipset imply does not support the higher clocked memory.
On my inspiron 8500, it only supports Pc2100 memory, but I bought 2 x1gb Pc3200 memory cards for it. The memory automatically clocks down to pc2100speeds, but the timings also drop. The memory timings drop to 2-2-2-5, which is really low for DDR memory. Plus at the time Pc3200 was cheaper than Pc2100 per Gb. It was only $100 a Gb than..
The memory may downclock but the performance loss is not a necessary side product. The timings on your memory have decreased, and the Pc2700 can max out the PC2100 bus, which should speed things up a bit.

K-TRON