Simple, simple question about Rams

[Woodchuck2000]

Originally posted by: Wiseguy69
If you can afford 3 sticks of 3500, why not just get rid of the 2100 and run in high bandwidth bliss?

It's well worth noting at this point, that very few motherboards can run three sticks of RAM at PC3500 speeds - most boards are limited to one or two sticks at higher speeds.

 

[CZroe]

What about dual-channel motherboards? I know it's not the same thing as "dual-bus" but with double the traces you'd think one set of traces could run at one frequency and the other could run at a different frequency. I know, I know... Engineering and technical support nightmare....

 

[Noriaki]

- All your RAM slots must run at the same speed (even on a dual channel board).

- You can set that speed to anything you want. If you have PC2100 DIMMs you can set them at PC2700, PC3500 or any other speed you want, whether or not they will be stable is another matter.

- The PCxxxx rating tells you two things: The manufacturer says the ram will run at LEAST at that speed and be stable, and if you set the motherboard to auto detect RAM speed this is the speed you'll get. It does not tell you the maximum speed the DIMM will run.

- If you have a hypothetical motherboard with 12,843 DIMM slots, and 12,842 of them are populated by PC3500 with the last populated by PC2100, on auto-detect RAM speed mode you will get PC2100 speed. Autodetect will always give you the lowest of all your DIMMs. Maybe your DIMM will run higher than that, you can always try, but auto detect won't do it for you.