Question about FSB limits and memory types

After reading around here for a while, i've learned that to gain the most performance, the memory speed and FSB of the CPU should be the same.

I'm planning on getting a QX6700 quad core cpu with an FSB of 1066MHz. If im planning on overclocking, does that mean i should also buy PC8500 (1066Mhz) DDR2 memory since the speed matches the FSB of my CPU, then overclock both the FSB of the CPU and the speed of the ram at the same time? Or should I buy faster RAM such as PC9200 (1150MHz) so that the speed of the RAM is already higher, and i'd only need to overclock the CPU to match it?

One reason i want to make absolutely sure about the RAM is because i planned on getting one of these boards:

BFG nforce 680i motherboard and it says it supports up to PC6400 (DDR800) ram. http://www.bfgtech.com/nForce680i_motherboard.html
EVGA nforce 680i motherboard and it says it supports up to PC9600 (DDR1200) but that speed of ram doesnt seem to exist yet. (http://www.newegg.com/Product/Product.asp?item=N82E16813188009

If i bought one of the fastest memory sticks on the market, such as the FlexXLC PC9200 (DDR1150) here, would i actually be able to use it to it's full potential?

http://www.newegg.com/Product/Product.asp?Item=N82E16820227184

Or should i get the fastest memory that matches my CPU's FSB here which happens to be the PC8500 (DDR1066) corsiar dominator:

http://www.newegg.com/Product/Product.asp?Item=N82E16820145043

Or should i just stick with the FlexXLC PC6400 (DDR800) here?

http://www.newegg.com/Product/Product.asp?item=N82E16820227185

So basically to summarize, Im getting a QX6700 quad core cpu, bfg nforce 680i or evga nforce 680i motherboard, and im looking for the absolute best memory to go along with these items (cost not an issue) and the answers to the questions above.

Thanks for your help

I think i've decided on the EVGA board instead of the BFG board just because the EVGA board has an extra slot that the BFG board doesnt have and a lot more people have reviewed it on newegg.. even though some of the reviews are a bit concerning. I think i'll take my chances.

Well either way, the 680i chipset is still kid of buggy. Some have great results, others have nothing but issues. I ditched the 680i and went with a single 8800GTX and an Asus Commando.

Right, unless you HAVE to run SLI, then go with a better chipset.

As for the RAM question, the default "system bus speed" of the QX6700 is 1066, but it's a quad pumped bus, so FSB is really 266 MHz. So if you use the 1:1 memory ratio, then 266 FSB equals DDR2-533.

If I'm not mistaken, the QX6700 has a default multiplier of 10X, so even at a respectable 3.5 gig overclock, the FSB is only 350 MHz which means RAM using the 1:1 ratio is DDR2-700. Almost any PC2-5400 RAM will do that or if you want a little more headroom, then get PC2-6400 (DDR2-800).

Ahh thank you that's exactly the information about the ram i was looking for. You made it perfectly clear and now the choice is obvious

About the 680i boards, I think i'll still try my luck with them because there's still a lot of people who have had reallly good luck with them as well. The worst that will happen is i will become a disgruntled 680i user and get a non 680i board

Back to the original question with the ram.... I dont think high end ram will go to waste in a 680i. Ive heard of ram that clocks to 1315 on those MBs. (Corsair's 8888s and 10000s)

I have also heard that there are 680i revision 2.0 that will suport 1000Mhz for the RAM instead of the usual 800mhz.

**Just something else to note here when using a quad core**
I have an Asus P5B Deluxe mobo that with an E6700 could do 503 FSB all day long. When I switched to a quad core, they have known issues with limiting the FSB on this board drastically. You should get anywhere from 320 to 400 with a P5B and quad, but realistically I max out at 340 FSB on my P5B Deluxe. This forces me to use the unlocked upwards multi to 12X. This will allow me room for the system to breathe on the FSB side.

Regards,