question on memory

ive got 2 256 400mhz moduals, so the memory runs at 197mhz.
so put in an extra 256mhz that runs at 333mhz. now memorys runs at 165mhz.

i thought more memory more speed. shouls i just leave the 333mhz in pc or will pc run better without it??.

or could i tweek memory timings??

 

I'm not sure why two sticks of memory that have the same speed would run at half speed when used together.
However, adding a slower stick does cause all of the memory to run at the slower speed.

 

The only think I can think of is either one of your DIMMs is not good (The slot where you put the RAM) Or....one of the sticks of 256 isnt really 400. You might want to trouble shoot it, but putting in one at a time. Put in one, boot it up, see what it runs at, shut down, take it out, put in a different one, lather, rinse, repeat. And yes, haveing two different speeds of ram in will cause it to run at the lowest speed.

 

DDR RAM runs at twice the bus frequency - so 400MHz RAM will actually only use a 200MHz bus. 333MHz RAM will use a 167MHz bus, etc...

When you mix and match different speeds of RAM the whole lot usually slows down to the slowest speed.

 

Wow I totaly forgot about that....Nice job fish, you hit the nail on the head.

 

so whats better 512 running at 200mhz or 768 running at 165mhz??

 

You'll have to try both and see which you prefer, as it all depends on what you're using it for.

 

pc games hl2, far cry, cs ect.... and some music editing software

 

The music editing stuff will probably be better with more RAM, even it if it is slower. For general windows stuff memory speed doesn't seem to matter so much.

The games are a tough call, some need super-fast RAM, some just need lots of it. I mostly play older games (I'm not paying £1000 for a PC to play newer stuff) so I don't know what kind of specs new games like. Try it with all the RAM in, then pull out the slower stuff and see if it makes it better or worse...

 

thanks

 

Woops, didnt mean to post, heh.