Weldzilla,

Unfortunately, boosting my memory speed over 1000 Mhz. (5-5-5-15) results in instabilities with MemTest+ unless I increase vdram over 2.1v That is too high without active cooling, especially since this is Micron D9 based memory. Since this not just a gaming computer, I need to maintain 100% stability. But remember, I'm running 4 of these sticks.

When I attempted your suggested 9x445 with the Ram at 1186 Mhz (5-5-5-15) with 2.1v and NB at 1.45v, MemTest+ failed. I never boot into Windows unless MemTest+ passes.

8 x 500 with the memory at 1000 Mhz. worked well at 5-5-5-15. But are there any benefits or drawbacks in running a 8x multiplier with a 500 Mhz. FSB? Real world benchmarks showed little improvement (PCMark).

Some also believe running the memory 1:1 with the FSB is preferred.

This is what Anandtech has to say about our memory (based on 2 sticks not 4):

G.Skill 2x1GB DDR2-800 CAS4 F2-6400PHU2-2GBHZ Kit
We may sound like a broken record, but again we have a set of memory from G.Skill that provides flawless operation across every DDR2 board we have tested with in our labs. The modules are Micron D9 based and offer excellent overclocking capabilities. This memory will run at DDR2-800 3-4-3-8 timings on 2.0V on most boards. These modules also reach speeds up to DDR2-1066 at 4-4-4-12 timings with 2.2V. Our top overclock on the DFI 680i board was DDR2-1160 at 5-5-5-18 timings with 2.30V.

Review of this memory indicating higher voltages required:
http://techgage.com/article/g_skill_...00phu2-2gbhz/2

Anyway, it was fun experimenting some more and I'm quite happy at the moment with a 100% stable overclock.