memory mix & match question

Custom / P5k
December 29, 2010 at 13:37:03
Specs: Windows 7, 2.664 GHz / 3327 MB
Hello everyone.

I have a PC based on an Intel e6750 Core2Duo, and 2 sticks of 1 GB each of DDR2-800 running at 5-5-5 timings. Running Win7 32 bit.

A friend gave me a 2 GB stick of DDR2-667 that he didn't need. I plugged that in, works like a charm, however, all my memory works at 667 levels now (which makes sense, I think).

Correct me if I'm wrong, but for 1333 FSB that the e6750 has, isn't the 667 ram speed the optimum speed anyway? Wasn't DDR2-800 overkill to begin with?

I do not intend to overclock, by the way.

There shouldn't be any performance loss, right? I mean, 2 * 1 GB of DDR2-800 at dual channel always get trumped by 2 * 1 GB of DDR2-800 plus 1 * 2 GB of DDR2-667 since the CPU can only use up to 333 FSB (ok, quad-pumped to 1333) speeds...???

Does the fact that I had 2 sticks in dual channel mode and now I have 3 sticks in total play a part at all?

Thanks :)


See More: memory mix & match question

Report •


#1
December 29, 2010 at 14:01:47
It will all run at the speed of the slowest modules.
this is normal so "2 * 1 GB of DDR2-800 at dual channel always get trumped by" a
2 GB stick of DDR2-667 so you are slower
You may as well wait and pick up another 2GB stick.DDR2-800 if you need it.
The slower RAM will slow you down.

Report •

#2
December 29, 2010 at 14:18:18
Sure, yes, DDR2-667 is slower than DDR2-800, of course.

What my real question is though, if that will affect *my* setup, when my CPU has a 1333 FSB. Isn't the general rule:

1333/4 = 333.
DDR2-667/2 = 333

so you keep a nice 1:1 ratio?

I am not sure how dual channel vs non-dual channel works though.

So, my question boils down to:

2 * 1 GB of DDR2-800 @800 in dual channel, on a 1333FSB CPU?
or
2 * 1 GB of DDR2-800 @667 & 1 * 2 GB of DDR2-667 @ 667, on a 1333FSB CPU?


Report •

#3
December 29, 2010 at 16:56:21
667 DDR is correct speed to run with e6750. Ddr2 800 can be underclocked to run as 667/533/400. Dual channel increase memory bandwidth. For e.g. 6400mb/s is a bandwidth for ddr2 800 and 12800mb/s is a bandwidth for ddr2 800(dual channel)

We can not fight new wars with old weapons, let he who desires peace prepare for war - PROPHET.


Report •

Related Solutions

#4
December 29, 2010 at 20:00:36
"so you keep a nice 1:1 ratio?"

Exactly right! But you should also run the RAM in dual channel mode, if possible.

4GB @ 667MHz in single channle mode @ 1:1 ratio is much better than 2GB @ 800MHz in dual channel mode @ 5:6 ratio.


Report •


Ask Question