First overclock, voltage questions

[nightmare75]

This is my first real attempt at overclocking here. I had a goal in mind of hitting 3.6 GHz with my Q6700, but I'm a little concerned about the voltages I'm going to need to get there.

Currently, I've got it running at 3.5 GHz (350 x 10) and CPU-Z shows 1.4v (it's about 1.43 or something in the BIOS) and my RAM is running at 421 MHz. I've got my NB and RAM overvolted by .04 v apiece. Temps are also starting to concern me at this point. Idle temps are fine; I'm getting ~38 C on all four cores. When I run P95, they hit the high 60s, occasionally touching 70 C.

The last few times I increased the FSB, I've had to up my vcore by .03-.05 volts to keep it somewhat stable. I know the processor is rated by Intel to be safe to 1.5v, but I'm a little worried about approaching that. How much higher can I increase the voltage before I should start worrying about having too much?

Additionally, how much benefit could I see from adding more voltage to the NB or the RAM? Would adding more voltage to either of those prevent me from having to add more to the vcore? My RAM is only rated to 1.9v, so I don't have a whole lot of room for increasing voltage there.

And finally, how much higher should I be able to go with the temps before I have to start worrying about being too hot?

I would like to mention that I'm mostly overclocking this far for benchmarking runs. For everyday use, I'm probably going to dial it back to about 3.0-3.2 GHz.

 

[BillParrish]

Temps are also starting to concern me at this point. Idle temps are fine; I'm getting ~38 C on all four cores. When I run P95, they hit the high 60s, occasionally touching 70 C.

At around 100C the cpu will send out a "I am getting hot" signal to the motherboard that would tell the stock cooling to go to 100% fan speed if EIST was/is active. Several deg C above that it would shut itself down. Prime95 on all 4 cores is pretty intense and seldom do we stress the machine that hard in real applications but you know more about what you run than me. So no worries - 80C would not bother me but everyone has their own personal limit.

I know the processor is rated by Intel to be safe to 1.5v, but I'm a little worried about approaching that. How much higher can I increase the voltage before I should start worrying about having too much?

You answered your own question, I would not go above 1.5V but its your cpu and when I did acheive (or not) my max OC I would then start stablity testing "backwards" to see if I could reduce the Vcore. Me personally would set it for 1.475 while doing quick stablity runs to take it out of the equation as I investigated the other voltages below for short runs. Higher is your call. I would be watching temps like a hawk if I had to leave it there for long and as soon as I had any kind of stablity I would see if I could lower it a notch or two.

Additionally, how much benefit could I see from adding more voltage to the NB or the RAM?

Go ahead and set the ram to 1.9V. You are not really saving anything not running it at its rated voltage.

MCH (NB) stock is 1.125 with an Intel datasheet max of 1.21 - this is the main voltage I would be investigating to see if increasing helps. A small fan glued to the MCH heatsink part of the heatpipe or direct a spare fan directly at the MCH and I would (remember this is me not you) run it up to 1.25 ish to see if it helped.

I would also in conjunction with the MCH voltage be looking at the FSB reference voltage aka FSB termination voltage to see if a bump or two helps with stablitly.

I would be booting into a copy of memtest86+ after I got it to bootup with changed settings so as not to trash my windows install and only after it ran at least the first few tests, then try windows.

Hope this helps. That last little bit of max OC is more an art and feel than anything else. Make sure your memory mulitplier/ratio is set to run the memory at less than its rated speed for now.

 

[Zero82z]

How much higher can I increase the voltage before I should start worrying about having too much?

You can go up to 1.5V without having to worry about anything.

Additionally, how much benefit could I see from adding more voltage to the NB or the RAM? Would adding more voltage to either of those prevent me from having to add more to the vcore? My RAM is only rated to 1.9v, so I don't have a whole lot of room for increasing voltage there.

Raising the memory voltage probably won't help much (if at all). Raising the NB voltage can help you with stability at higher FSB speeds. It won't necessarily mean that you can use a lower Vcore, but it can help you reach a higher overall overclock if you've been running into an FSB wall.

And finally, how much higher should I be able to go with the temps before I have to start worrying about being too hot?

I'm not sure what Tjmax is for your CPU, but basically, you can go right up to that number without harming anything. In fact, it is impossible for you to harm your CPU with too high of a temperature because its built-in thermal protection features will slow it down and shut it off if it gets too hot. My personal comfort zone is below 80C or so, but realistically the temperature isn't something you need to worry about.

 

[nightmare75]

Ok, thanks guys. I appreciate the advice.

Is there an app out there that will show MCH temps? I'm a little curious to see if I need to look into extra cooling there if I'm going to be adding voltage. I have a case with good airflow, but I have some extra fans lying around and it would seem silly not to use them if it turned out that I needed them.

I noticed that running Memtest was recommended. Am I likely to get RAM errors by overclocking? My RAM hasn't run much over its rated speed, but is it likely to produce errors if I do bump it up? Or is Memtest just a good general indicator of system stability.

In any case, I'm done pushing it for the night. Like I mentioned, the really high speeds are mostly for benchmarking and bragging rights. As such, I've dialed it back to 3.2 GHz (320 x 10, also, hooray for OC profiles!) and I'm going to stress it overnight to make sure it's stable. I'm going to leave it at 3.2 GHz for everyday usage and I'm just making sure that it's rock solid. What I'm wondering here is if I would see any benefit of going with 400 x 8 instead and then running my RAM at a 1:1 ratio. I've heard that some people prefer to do it like this, but I'd like to hear some reasons why this is beneficial or if it's worth running the FSB that much higher.

Anyway, I'll look into pushing it further tomorrow. I'm really hoping that I can get to 3.66 GHz, which would be a 1000 MHz above stock.

Thanks again.

 

[Impulse]

Just touch the NB heatsink, if it's too hot you'll know it. Your RAM can produce errors if you OC it and even w/o OC'ing it's plausible the memory controller (that's on the NB) could produce erros... Memtest86+ is just a good diagnosis tool to rule out the RAM as a culprit in general though, not necessarily an indicator of overall stability (for that you'd wanna use Prime95, OCCT, Linpack, etc.).

As far as 320x10 vs 400x8... Some people suggest using a 1:1 ratio puts less strain on the memory controller on the NB, but in your case 320x10 is probably gonna put much less stress on the mobo overall so I'd stick with that if you can keep your memory within spec thru a divider (5:6 would actually have it under spec at 768MHz, dunno what other dividers you've got available, nothing wrong with being slightly under tho).

 

[nightmare75]

My motherboard doesn't actually let me select a divider directly. However, it lets me pick the DRAM speed from a list of values that would correspond to some divider (I think). It also lets me select the FSB strap, but I've left that on auto since it picks whatever is correct for the DRAM speed and FSB. Actually, Impulse, looking at your sig, we have the same motherboard. Would you care to offer any other insights on overclocking with this particular model?

Right now, CPU-Z is reporting that my RAM is running at 400 MHz with a 4:5 divider. I'm guessing that this is absolutely fine since that's what the memory is rated at.

Anyway, I'll get back to you guys tomorrow when I've tried going a farther with my overclock. You've all been a great help

 

[Zero82z]

Would you care to offer any other nsights on overclocking with this particular model?

Nothing particularly special about overclocking with this board. For starters, keep the RAM at its lowest possible divider while you're working on the CPU so the only thing that will limit you is the chip itself. Leave the FSB strap on Auto. The only settings I had to touch to reach my current overclock were the FSB obviously, the CPU Vcore, the MCH voltage, the FSB termination voltage, and the CPU PLL voltage. Those are the settings I recommend that you play around with, since they have the most effect.

 

[TechHead]

@Zero82z, can you post your vCore, vMCH, and the others? My Q6600 is stuck at 3.1GHz on my P5Q-E, which has a similar BIOS layout.

 

[nightmare75]

Alright, a little more tweaking today and I reached my goal.

http://valid.canardpc.com/show_oc.php?id=579958

I'm pretty happy with this. I think I could go a little higher, but I'm currently at 1.475v and the temps are starting to scrape 80 C on stressing. Sure, I could push it some more, but I'm satisfied with how far I've gotten.

@Zero82z, can you post your vCore, vMCH, and the others? My Q6600 is stuck at 3.1GHz on my P5Q-E, which has a similar BIOS layout.

I know you didn't ask me specifically, but I'll share my settings just in case it'll help you out.

When I have my Q6700 at 3.6 GHz, I have the following settings:

vcore: 1.475
CPU PLL: 1.60
FSB Termination: 1.30
RAM: 1.8 (stock)
NB: 1.20
the rest: auto

And when I have it at 3.2 GHz:

vcore: 1.2812
everything else: auto

Hope this is helpful.

 

[Zero82z]

@Zero82z, can you post your vCore, vMCH, and the others? My Q6600 is stuck at 3.1GHz on my P5Q-E, which has a similar BIOS layout.

I don't remember offhand (I set this overclock back in early October and I haven't touched it since), but I'll see if I can reboot a little later and check that out for you.