I had been using the 1.3 preset:

Max: 1300000

Slot 1: 400000
Slot 1v: 27
Slot 2: 700000
Slot 2v: 38
Slot 3: 100000
Slot 3v: 56
Slot 4: 1300000
Slot 4v: 68

Using this preset I basically had 4-5 reboots in a matter of 4 hours.

I liked the speed while it was functioning, but have since moved to the 1.2 preset (I'll spare the details), but what I'm wondering is that from reading a fair bit, I'm seeing higher voltages seem to equal greater stability, and so I'm wondering at 1.2 or 1.3, what are safe voltages to play around with that would fall in the category of "high voltage"?

I've been searching the forum here, and at XDA, for answers for a while now with no luck - so if this has been a common discussion and gets no responses I'll take the hint and try harder.

Well just a minor update, but it's been over an hour at the preset 1.2 with no reboot, so I'm guessing the 1.3 needs a bit of tweaking I'm simply not yet comfortable with.

If this stays stable, it might be good enough. The performance increase is still notable, though also not as much.

The voltages may be a little too low for the first 2 slots.

Might try upping them a little bit and see how that goes.

Can you recommend any increments to try?

Apologies, I'm quite new to the overclock world and have had a difficult time understanding what kind of parameters are safe in these kinds of things.

Try

Max: 1300000

Slot 1: 450000
Slot 1v: 36
Slot 2: 700000
Slot 2v: 48
Slot 3: 100000
Slot 3v: 55
Slot 4: 1300000
Slot 4v: 67

Somewhat how I have mine setup just at a lower overclock. I tweaked the voltages a bit to kind of match how that would work with the 1.3GHz settings. Let me know how it works out!

Mega, thank you. Will give this a shot this evening. Really appreciate it.

No problem man! Let me know if you need anything else!

Well early signs are promising, my first reboot (which I thought was just a fluke) earlier was less than an hour in. Temp is remaining pretty consistent at approximately 86 degrees F, everything running very smoothly.

Hopefully the same can be said around this time tomorrow, but regardless of the result thanks again for trying to lend a hand, Dustin.

Post back and let me know how it runs threw the night, if the reboot problem proceeds, I'll tweak with my D2 when I get home and see if I can't find a set profile for ya!

And no problem man, that's what I'm here for!

Well, a couple hours on and it's reboot a couple of times so I've reverted back to the 1.2 profile (the most stable thus far, no reboots), does this generally indicate there's still an increase needed?

Also, any idea as to why the issue diminishes at higher voltage?

Because at lower voltages, it becomes unstable because its not getting enough juice. So it just shuts off. Ill work on a custom profile for ya tonight.

Sent from my DROID X.

i use to be able to run at 1.4 on the newest apex rom with only one unexpected reboot since it came out. On squidlyrom i was able to go as high as 1.35 with same results but lately i'm back to 1.35 max i dont know why but i'll stick with 1.35 does anyone know why this would happen how can i run at 1.4 no probs for a long time and all of a sudden its 1.35 max.

I'm hoping someone can hack that damn bootloader so we can load up custom kernals and one day get cyanogenmod on our phones. i was all hyped for the moto etna but now i'm not sure going to wait it out. my brother gave me the d2 for an early christmas present so i'll rock it for almost a year and hopefully something will come out thats perfect for me until d2 all the way.

Here is all the information you need to overclock intelligently. While it was written for the D1, the theories are still valid: http://www.droidforums.net/forum/rescue-squad-guides/47871-overclocking-101-a.html

Cheers, thanks again man - you've been boatloads of help.

And this is a HUGE help. I've been basically looking for just this and failing utterly and completely. Thank you.

So I've been riding the 1.2 preset in the DX/D2 Overclock app and it's been entirely stable, but it's a wonder how that little .1 difference between clocking at 1.2ghz and 1.3ghz makes in performance.

I've still had little to no luck with any recommended voltages at 1.3 - but I'm seeing some folks report stable profiles at as high as 1.4, is each device really that different or am I just barely missing something crucial here?

Yes, each device is different. I believe in that thread I linked to earlier, he talks briefly about the fabrication process and gives a link to an article that explains it in detail.
In a nutshell, if you do a fabrication run that nets 1000 chips, you could potentially have 1000 different maximum settings.
On my old Droid 1, I could never get it stable over 1.2GHz, even at High voltage, even though some people could go up to 1.4GHz with Ultra-Low Voltage. I could also never get any ULV kernels to work at all, even at the stock frequency.
With my Droid 2, I'm stable up to 1.35GHz ULV, but once I go to 1.4GHz the entire system becomes unstable and apps crash all over the place. I haven't tried to see if I can go faster at a higher voltage because I don't actually have my phone overclocked, the extra .35GHz doesn't make enough difference in my daily use to justify using it.
I've even seen someone with an OG Droid that couldn't go over 600MHz even at High voltage or the system would just freeze and boot loop.

I just used this overclock program and got a little carried away and checked to see how the phone would work at 1.4. Turns out the phone did not appreciate it and now, although it is set to wait 90 secs before it O/Cs, it reboots before the app is loaded up for me to go in and change the settings. Anyone have any suggestions on what to do? It's been letting me kill it with the task killer once but then it reloads and then reboots.

Nevermind that last one. I was able to get into Superuser and deny the permissions to root for the DX/D2 Overclocker before it loaded and I changed the settings back. Definitely unchecked the "start at boot" option. I am a rookie so this lesson was learned.

Is there really that much variance between phones? I've been using Droid Overclock, running the preset 1350-1100-900-400 scale (low voltage). Been stable for over a week, no unexpected reboots...And unless the battery is below 30%, I'm on a 1100 min / 1350 max profile.

Well, it's only a single case comparison - but yeah, they seem to be. Mine will absolutely not tolerate anything in the 1300 realm for longer than an hour or so.

The 1.2 preset has basically been the best I've been able to do, and while the performance increase is modest, it has provided the little bit of extra "oomf" I was looking for.

Been quite happy since the whole feeling out process.