Core 2 duo FSB to RAM speed query.

[mogwai]

I have started looking into a new Core 2 Duo based pc and am a bit confused as to why when all the Core 2 Duo's listed on the site have a FSB of 1066 Mhz, that all the bundles only come with 800 Mhz Ram.

Surely you would want the RAM at the same speed as the FSB otherwise you are introducing a bottleneck?

 

[Zogger]

Rated FSB is 4x the fsb in the bios.
an FSB of 400 in bios @ 1:1 is the rated speed for 800MHz DDR2
1066FSB is 266, so 533MHz for RAM

 

[Corasik]

Memory bus is 128bit (dual channel), but CPU bus is only 64bit, so 1066FSB is 1:1 with 533 ram. 800Mhz ram is supplied with the bundles to allow better overclocking perhaps 800Mhz ram's good for 1600FSB 1:1

 

[tomos]

i have g.skill 6400 ram and that gives memtest errors @ 200mhz fsb.

surely that ram should be good for higher than that?

 

[mogwai]

So if you run the PC 6400 RAM at stock in conjunction with E6700 core 2 duo, what frontside bus do I end up.

As with my current rig a P4 c 3 Ghz with PC3200 ram I have an 800 Mhz FSB which I thing is 200 mhz x 4. So how does this translate to core 2 duo.

 

[thefishdude]

fsb of all the core 2 duos is the same. 266 quad pumped to 1066.

6400 mem at stock is 800mhz. on all the core 2 duos.

the mem frequency only really changes from stock when you start to do over clocing of the cpu.

 

[tomos]

when you say 800mhz, do you mean an actual 800 or 400?

 

[Zogger]

400 as CPU-Z would report.

 

[tomos]

just wondering why i am having probs running 6400 ram @ only 200mhz

 

[charltonfan1]

just wondering why i am having probs running 6400 ram @ only 200mhz

Probably because that is half its rated speed i think. Run it either 1:1 with the CPU at 266mhz, or higher

 

[Ch3tan]

just wondering why i am having probs running 6400 ram @ only 200mhz

Have you set the voltage correctly for the rated speed?