@wpcoe - this may confuse more than enlighten, let's see...
First, honolululu is right about Core Temps - the version you want for the E6750 is 0.95.4, and it does show up as that value in its Title bar when running. Second, I can't find PC-4300 ram - do you mean PC-4200? No matter. I thought you might enjoy a couple of links to read over concerning Ram speed. The reviewer, Steve Walton of Legion Hardware, has made it his business to test the conventional wisdom that faster Ram (as well as larger quantities of the stuff) will always yield faster results. Steve's tests seem to indicate that this is not necessarily so - at least with Core 2 Duo. Graysky, from right here at Anandtech, has also done some great testing, along with others following his thread, on latencies - look for it, very interesting. Here, check out a couple of these links on Ram speed:
http://www.legionhardware.com/document.php?id=628
http://www.legionhardware.com/document.php?id=630
Graysky's thread (one of many on the subject):
http://forums.anandtech.com/me...=2112855&enterthread=y
The point is, I wouldn't worry too much about the PC-4200...not TOO much anyway...
As to VDroop, most boards exhibit this kind behavior, and many power supplies too, to a certain extent. At your modest overclock, you really don't need to worry much about it. I have noticed some variation in the various bios versions when looking at the implementation of EIST/C1E. As I've posted before in this thread, bios versions for my board, the GA-P35C-DS3R, are not consistent re: EIST/C1E and voltage at idle. The F2 bios seems to work best for me - it not only changes the CPU multiplier to x6 (at idle) - it also reduces the voltage to the CPU to 0.963 (the absolute minimum voltage cited in Intel's spec sheets.) More recent versions of this board's bios don't undervolt like that - some drop voltage to 1.152, and some don't allow it to drop at all. I'm no electrical engineer, but I can't see the advantage of dropping the multiplier at idle (reducing FSB at the CPU) without also decreasing voltage...
Honolululu reminds you that I have a weird E6750 - "normal" voltage, the value that shows up in bios, is 1.28, as opposed to 1.35. This does give me some advantage in overclocking this thing at smaller overall voltages - I get to 3.52GHz, completely stable, at a 1.36250v applied in bios. I own another E6750 that registers "normals" at 1.3500v, like everyone else.
As to your Ram instability with different bios versions, I can only offer you two comments:
1. You are running 4gigs, and I've read many threads where 4gigs can be more "sensitive" to bios settings.
2. So check your Ram spec and ensure that you are giving it the specified voltage.
Because if I understand you correctly, if you are trying to run your Ram in sync with your CPU, at 1:1 ratios, these are my assumptions...so...
Your Ram is PC-4200, spec'd at DDR-533, which is 2x266. To achieve an overclock of 3.0GHz, 1:1 ratios, and using the default multiplier of x8 on your CPU, you're setting your Ram at 375 (x8 = 3.0GHz)? If any of that is true, that's a pretty hefty overclock (+40%) on ValueRam, particularly if you haven't made an attempt to adjust VDimm voltages to your Ram's specs (check your Ram's spec.). Perhaps you might try setting the Ram to 333, which would bring your CPU back to stock speed of 2.66GHz? (333 x 8 = 2.66GHz) That still represents a 25% overclock on your Ram, but perhaps more do-able? Honestly, I don't think you're going to notice much of a performance difference, real-world, running at 2.66 vs 3.00Ghz...
Regards,