A few OC questions

[koldun]

Okay, so I've been fiddling for a few days with my new Q6600 and Asus x48 Rampage Formula.

So far, the highest I've been able to achieve is 3.48 (433x8) with the vcore auto-defaulting to 1.37v.

Question 1 I know Asus tends to overvolt their stuff, so is 1.37 high? CPU temperatures barely hit the low 50s even during Orthos/Prime95, and that's with the cooler only working at about half capacity.

Question 2 Now for the life of me I can't get it to boot @3.6Ghz. It refuses to boot either at 400x9 (which I frequently read people accomplishing) or 450x8. So is there something else I can try other than screwing around with FSB and multiplier?

Question 3 Another thing of some concern is the North Bridge. Now this bitch idles at 65C, and starts reaching into the low 70s after about an hour or two in Orthos. According to the manual, this is within the range of the motherboard, but doesn't 65 seem a bit high for an idle temperature? It actually defaulted closer to 70 with a NB voltage of 1.62v, so I took it down to 1.55v with seemingly no incident, but also not much result.

That leads to Question 4. At what point do I know to stop lowering the voltage? Will the computer simply fail to boot (I'm sure that's inevitable), or must I run a (24-hour?) stability test every few increments to really know for sure?

Finally, my last Question 5 pertains to RAM. I currently have 4gbs of Gskill DDR2-1066Mhz ram, that's underclocked to 866Mhz to match the FSB. I figured, alright, it's underclocked, so maybe I can tighten up its default 5-5-5-15 timings a bit. However, changing any of the timings has the system give me some error about checksum not matching and having to repair my OS. Changing the settings back rids me of the message. Is this Vista64 simply being lame (maybe thinking the hardware is changed?) or does this have to do something with the RAM itself?

Thanks in advance for any replies (and if it's warranted, don't hesitate to drop a link, and tell me to STFU and RTFM).

 

[hvrt]

Have you upped the voltage on the RAM? Try 2.1v and see if that works.

 

[graysky]

Best link I can point you to is my C2D/C2Q Overclocking Guide which I put a bit of work into.

A1: 1.37 isn't that high for that o/c level in my opinion. That said, yes, auto vcore does tend to overvolt; you can likely lower it (follow the minimizing your vcore section of in my guide).

A2: Have you upped the other vcores on the board such as NB, VTT? Again, see my guide for more.

A3: I haven't seen anything officially published 'safe' voltage or temp ranges for NB's. Just because you have an option to use 1.65 V doesn't mean that it's safe. 65 idle is HOT for P35... I dunno about an X48 as you have. Have you adjusted your VTT?

A4: Again, see the guide, but you need a good 24 h of p95 stability (large FFT's) to call a given set of vcores/settings stable IMO.

A5: Some people can tighten the first four timings, but I'd recommend you leave them @ 5-5-5-15 as you attempt to stabilize. Also, use the default DRAM voltage.