Changing the Memory divider enough to "rule out" RAM?

[sidefxv1]

OK, so I have things overclocked nicely and now want to push it a bit more. Most things are fixed in the BIOS, so I just want to up the CPU clock. Of course as I do that the RAM freq will go up as well. If I change the divider so the RAM is at ~800 rather than the current 1000, can I then up the FSB freq and, as long as the RAM stays below 1000, safely assume that it's the CPU (or possibly mobo) and not the RAM that's the problem. Or is there more at play here?

 

[sidefxv1]

no problem in running the Ballistyx at 1000mhz at 2.25V at 18-5-5-5
and the board should take the 500 fsb easely( peraphs you need to up the voltages a bit)

Heh, no problem running at 1000MHz, 10-5-4-4 either

Think I tried maxing the FSB when I first got the system and it seemed at the time to top out at 450. However I think that was without tweaking the voltages... and may have just been a hole there?