2.4C ....is the Sudden Death Syndrom still occur ?...at what Voltage is unsafe ?

[trichard68]

:)

[FIZZ3]

Most likely yes & more than 1.725v actual is approaching the red zone.

[Icarus]

I would say anything about 1.675v is dangerous. especially if you don't have watercooling or anything better.

[FC]

you can use 95% the potencial of the newer cpus at default vcore, raising it won't help much. my 2.4c is not stable at 3.6ghz even with 1.7v, but total stable at 3.5ghz with 1.5v

[KiwiRack]

Intel's FAQ notes that 1.6v is considered the high point & describes why, but aside from that, cooling should be the larger of the two issues, and not just the CPU voltage -But the chipset as well, as one increases the CPU voltage & increases the OC most plle forget the other ironies of OCing. It's more than just voltage, it's all about heat.

As an aside, there is a division between those plle who believe in "burning in" and those that don't, from first hand experience I can safely state that after burning in I was able to drop from 1.7 -All the way down to 1.575.

I have also heard that the 800fsb Intel CPU's don't care about increased voltage/performance. As FC notes.

Personnaly I would not consider running a voltage (post research) above 1.7 on air, and that's with the top liners {piped air, as an example}; and not for very long, with excellent cooling 1.6 is tops for me -Long term. While burning in I did see a marked improvement in speed @ 1.6 vs stock 1.525, after burning in I could not see any difference from 1.575 -1.7v at all, and I mean zero.


Voltage, setup for friends viewing -So it's not a Pro evaluation (http://www.aristotle.net/~nzkiwi/mobo.html)

Cheers ;)

[JaY_III]

if you can not afford to break it, dont raise the voltage over 10%
if you got good cooling, and are willing to take a small risk, dont go over 15%

If you got VERY good cooling and are willing to kill your CPU dont go over 20%. also note the positive effects of inscressing the Vcore fad fast

20%+ you better be freezing that CPU and know it has a good chance of dieing. Also the postive effects of Overcloting the CPU are very slim to none at this point

[NookieN]

Originally posted by FIZZ3
Most likely yes & more than 1.725v actual is approaching the red zone.

I would argue that 1.725V _actual_ is WAY too high. The nominal Vcc under load is about 1.4V. So if you're forcing the chip to 1.725 under load, that's almost a 25% increase.

Keep the programmed Vid at no more the 1.75V. The actual voltage the chip gets shouldn't be more then 1.6V if you want to stay in the "safe" zone.

[FIZZ3]

Originally posted by NookieN


I would argue that 1.725V _actual_ is WAY too high. The nominal Vcc under load is about 1.4V. So if you're forcing the chip to 1.725 under load, that's almost a 25% increase.

Keep the programmed Vid at no more the 1.75V. The actual voltage the chip gets shouldn't be more then 1.6V if you want to stay in the "safe" zone.

Not all boards undervolt though. Mine does the opposite and that 1.75v would result in 1.83v idle. But that's a side issue.

I think 20 to 25% voltage increase is a reasonable upper limit. Of course I agree that lower is always safer, but it's a bit of a risk/gain estimate that is best made by the overclocker himself. For example, I've not seen good increases in OCed speed from increasing P4a/b chips' voltage over about 1.70v. They would just not get stable.

[JaY_III]

Originally posted by FIZZ3

I think 20 to 25% voltage increase is a reasonable upper limit.

NO, NO NO NO and NO.
25% is CRAZY
I still dont know why so many people are clueless when it comes to SNDS and what causes it. The reason you keep frying CPUs is because you are cooking them with voltage.

Dont overvolt any IC, being CPU, RAM, GPU or whatever more than 15% without killer cooling

10% is a reasonable limit if you dont want you hardware to die.
15% is a reasonable limit with a small risk, but with good cooling it should be ok.

so lets take a D1 stepping P4 for example. Vcore ranges from 1.475 - 1.55V, and we will use 1.5V for these examples

so a 10% inress from 1.5V is 1.65Vcore, should be used as your safe Vcore max if you dont want to kill anything
With some good cooling and minimal risk you will get a 1.725Vcore. (but good cooling is a must)

As for a 20%-25% incress, that is gona be one dead chip as you will be running a 1.8-1.875Vcore
SNDS, i think not, Overvolted NDS i think so.

[modenaf1]

Originally posted by trichard68
:)

wow! i didnt know intel had the sudden death sydrome!! i thought only AMD's had SADS.


anyways, i think no more than a .1-.3 vcore increase is safe. WITH COOLING. if it is already running hot, whatever component that might be, DO NOT OVER VOLT!! i think if it is hot and getting more voltage EVEN IF it dosent make it too much more hot you shouldnt.

it kinda like the human body, i dont know about some people but when you are so hot that you feel like passing out, the last thing you want to do is eat right? well, think of food as being the voltage.

[FIZZ3]

Originally posted by jAY

As for a 20%-25% incress, that is gona be one dead chip as you will be running a 1.8-1.875Vcore
SNDS, i think not, Overvolted NDS i think so.

1.4v stock at 1.7v is about 21% increase, not 1.8-1.875 as you mentioned...

In any case, for a 1.5v chip that % NookieN provided would be too much indeed. As I said, I'd keep it under 1.725 in all cases. And yes, good cooling is always a prerequisite.

//edit:// Hm thinking about the numbers made me wonder whether the P4 core has a structural barrier at ca. 1.7v or that it's a matter of relative increase. I tended to the first, also because the chips are all made equal and some fed more voltage when needed. However, given these two scenarios it may be better advice to take a safer approach and to not overshoot the 20% even on 1.4v stock voltage.