mine is a gigabyte, i can use ddr2 1200 OC but not at stock fsb... so if you don't overclock the max speed of your memory will be 1866 even if you have 2100mhz ram... but you can put 2100 and when you will bump the fsb with the max memory multiplier, it will reach 2100 no problem... The 1866 stick will never reach 2100.

it's just a matter of overclocking marketing cause they certify this motherboard is capable of running 2100 memory on a processor that is max theorical ram speed is 1866... also have some more option on timing...

PS: mine have also an option to tighten the timing in bios if you're not running at this full speed (i use 1066mhz and run it @ 1126mhz but with 1200 timing (so it's 5-5-5-15-51 cr2 with perfomrance level of 7) if i use 1066 settings it run @ 5-5-5-18-64 cr2 performance level @ 10 so it's more performant with the 1200 timing although i'm not running @ 1200mhz... it basically trick the motherboard into thinking it's 1200 ram but underclocked so it tighten the timing a lot...

You can buy 2100 ram and run it @ 1866 but with really tight timing it will explose benchmark too !!!

You said "you can put 2100 and when you will bump the fsb with the max memory multiplier, it will reach 2100 no problem... The 1866 stick will never reach 2100." So if i use 1866 chip, I can never oc to 2100? Can't you set the fsb and memory multiplier to 2100 and then set the memory voltage to supply the extra power needed, it would not overclock like you can with a CPU?

the Memory will have a multiplier but at stock fsb, the max memory multiplier will be 1866 so the ram never go faster than that unless you raise the fsb... with a fsb raised up the mem will be ok at 2100 speed...

but you can run 2100 memory stick @ 1866 and tighten the timing a lot so it will be as fast as 2100 speed...
(for me it's the lowest setting cause @ 1066 5-5-5-15-52 or a 800 @ 4-4-4-12-40 there's roughly 5% difference in bandwith and almost no difference in latency so 1866 tight vs 2100 normal should be about the same...

Thank you for clearing that up for me. Every thing you told me in the last two posts was exactly what I wanted to know, save two more things. On a MB, it's top supported ram was 2100oc. Can you use a 2600 or 2800 chip? Or dose the MB have support that ram before you can use it?

And if you use 1866 tight instead of 1866 normal, is there a increase in heat production? 1866 tight would use less voltage but that would increase the work load right?

1866 tight is the same as 2100, you'll need more voltage and more heat will result... also real1866 will not go tight they simply crash cause they are not designed to be running at fast timing like the 2100

ex: 2100 9-9-9-24 will do 1866 8-8-8-20 at same voltage but 1866 9-9-9-24 will do 8-8-8-24 only at 1333 speed and maybe you'll have to add voltage too... there's no "standard" it's try and try again...

my 1066 5-5-5-15 PL 5 reach 1126 on same timing but i release the performance level to 9 to reach that... but i can run 800 @ 4-4-4-12 with PL 3 and that's about 50 to 150mo/s difference on a 9000mb/s range in benchmark... I only run @ 1126 to match my FSB so it's only needed for overclocking in the high range like me cause my lowest multiplier gave me this speed (ddr2-667 multiplier gave me 1126 because of the fsb)

PS: 1866 tight it's the same memory than 2100 normal like my 1066mhz stick it's tight 800mhz but running faster instead of running tighter (faster is more likely to add bandwith but like i discover, not by much vs tight timing) Anyway, i don't think you'll notice the difference (i didn't so)

Good memory will only help you to reach really really high overclock and on new core archictecture it doesn't make the biggest difference like the older architecture because the memory controller is no longer on the motherboard so the response time is simply faster... no intermediate between to slow the process that need faster component to cut this time out to minimum...

I'm not a pro at overclocking or anything, but I believe the fundamental of overclocking any component is using safe voltages that the product is able to handle. You want to make sure you will not damage the product by using a voltage that is too high of range for the component.

The second is heat. Heat, or should I say excess heat, is a by-product of overclocking. Make sure the device you are overclocking has sufficient cooling.

The third fundamental is stability. Stability of the system after making these changes is a really important factor in my book. You can get a system to run a component or components that are overclocked, but are they performing ideally? A great example is that you may be able to overclock RAM, but it in turns causes intermittent BSODs. Another example is you may be able to make a graphics card work at a higher frequency, but does it cause artifacts on your screen when using 3D applications, or does it cause the game to crash?