[jamoley]

i have two 512 sticks of ram and one 256. if i use them altogether will the 512's only run as fast as the 256. i read somewhere that they should all be the same, any advice would be great

 

[killakrust]

You have to run them all at the same speed, so yes this limits it to the slowest ram. But I would not reccomend mixing ram of different speeds anyway.

Are you sure they run at different speeds?

 

[keymaker]

if all ram sticks are the same speed and support the same FSB speed, then they will all run at the same speed. however, if the 512megs sticks of ram are pc3200( 200mhz FSB supported), while on the other hand, the 256megs is pc2700(166mhz FSB supported), then you are overclocking the 256megs ram stick.

also if you are mixing ram brands, stability issues can arise. good luck

 

[Sarge]

It depends if you're talking about straight SDRAM or you're talking about DDR. DDR ram can be overclocked, while SDRAM cannot.
Use the RAMs' model numbers and their MFG's web site to find out what their rated speeds are and what type of DIMM they are.

 

[Chevy]

Don't forget to check the CAS timing as well. While FSB speeds will step down (PC2700 will drop to PC2100 if it's in the second slot and slot 1 is PC2100) CAS timing is not so easy going (CAS 3.0 in Slot 2 will not work if there a CAS 2.5 stick in Slot 1)

** You may be able to set this manually in the BIOS, but set it to the slowest stick.

 

[Sarge]

Chevy is correct (of course) about CAS timeing. IF you have a BIOS that can automaticly adjust the CAS timeings for you to match your adjusted FSB, then it's a no-brainer. Otherwise, you have to calculate the adjusted CAS yourself. You can dammage the DIMM sticks or even the DIMM slots if you screw up the calculations badly enough, but usually you'll just lock up the system long before that happens. Just be carefull.