Overvolting damages CPU instead of High Temps?

[karioskasra]

I ran into an article about a year ago that insisted cpu damage results from overvolting as opposed to high temps (assuming decent cooling.) The example given had something to do with transistor decay (can't recall exactly) but supposedly a well-cooled system keeping load temps down to 40C or so will still be unable to prevent a severely overvolted cpu from being wrecked. These days I see people raising vcore as high as their temps will allow.

Myth?

 

[Capitalizt]

voltage = heat

heat = CPU death

That's what I've always been taught. I don't think voltage is the problem...The HEAT that voltage causes is what actually melts the computer components. If you have some insane below 0 liquid nitrogen cooling + 20 case fans, you could probably get away with a normally "crazy" vcore level.

Don't try it though. I'm paranoid, so no matter how cool my system is, I refuse to go over 1.5 vcore.

 

[MarcVenice]

Electromigration, http://en.wikipedia.org/wiki/Electromigration

Thats what high voltages do. There's a reason many guides suggest only adding 0.1 or 0.2vcore, where 0.2 is allready quite a lot.

 

[graysky]

A little voltage translates into a lot of heat. Here is a more detailed analysis of two difference vcore settings and the temps they produce on a Q6600 @ 9x266=2.4 GHz as well as @ 9x333=3.0 GHz. The two voltages I used were 1.112 V and 1.232 V (both of these are the load voltage, the actual BIOS settings were 1.1375V and 1.2625V respectively).

2x orthos ran for 30 minutes and the temperatures were averaged over the last 10 minutes of those runs (well after they stabilized). Room temps was 75-76 °F. Notice that the difference in voltage is ONLY 0.120 V or 120 mV, but this seemingly small difference brought the load temps up by an average of 6-7 °C per core!

Run1 (9x266 @ 1.112 V), Average temps (°C): 51,52,50,50
Run2 (9x266 @ 1.232 V), Average temps (°C): 57,58,57,57
Differences (°C): +6, +6, +7, +7

Now if I add a faster FSB, they increased further:

Run3 (9x333 @ 1.232 V), Average temps (°C): 61,61,60,60
Differences from lowest voltage (°C): +10, +9, +10, +10
Differences from same voltage (°C): +4, +3, +3, +3

 

[betasub]

graysky, your comparison would be easier to understand if the room & CPU temperature readings you give were on the same scale.

Thermodynamically it's obvious that room temps of 75-76F are less than CPU temps of 50-60C, but by how much? I guess I'm gonna have to find a conversion table...

 

[MarcVenice]

Heres a little tricksy, type 75 Fahrenheit in Google. It will then tell you how many degrees celsius it is.

75 degrees Fahrenheit = 23.8888889 degrees Celsius

 

[Deliximus]

electromigration is gonna be the killer of your cpu in the end.
heat will do its part but overvolting by a lot will killl your cpu in the long run no matter how cool u keep it.

 

[idiotekniQues]

so if i am at 1.45v idle, 1.39-1.40 load, which is less than .1v over the intel rated 1.375 for this chip, i should be dandy then since my temps are just fine.

 

[Nathelion]

Both heat and volts can kill the chip, it's just a matter of what ends up doing it first. A highly overvolted chip will die fairly soon, no matter how cool it is. A very hot chip will also die eventually, no matter how low the voltage is. Of course, the two tend to come hand in hand, but I have had it from multiple sources that voltage is actually the more serious CPU killer.

 

[idiotekniQues]

well lets talk time here then.

do these experts have any clue on that?

who cares if a .08v overvoltage takes a couple years off your chip's 10 year durability, considering it will still last far beyond a 3 year upgrade cycle that is the max a lot of us hold to.

 

[QuixoticOne]

The experts have a great clue and can tell you precissely what the bell-curve of
failure probability vs. time would be.

Trouble is it's a pretty broad curve and just because "average" MTBF = 5 years, doesn't
make someone feel better if theirs is one of the 1% that fails after 6 months,
and doesn't mean that yours might not be one of the 1% that fails at 10 years.

If you keep the temperatures WELL UNDER stock Intel HSF temperatures
for the chip that it'd have at stock speed even if you overvolt / overclock
moderately you're probably overall not hurting your reliability too much.
In practice you may need water-cooling or very high end air cooling to do that though.

If you run the chip AT the same kinds of temperatures Intel's stock HSF would
give at Intel stock speed and Intel stock volts, BUT you're overvolting and overclocking,
there's no question that you'll stress the chip more than the "normal" stock amount,
and it'll fail sooner.

If you run the thing hard 27x7x365 always on that'll take a lot of life away vs.
running it for 4 hours a day or whatever.

If you disable sleep / SpeedStep / Cool_N_Quiet or whatever then that'll take a toll too.

 

[idiotekniQues]

Originally posted by: QuixoticOne
The experts have a great clue and can tell you precissely what the bell-curve of
failure probability vs. time would be.

Trouble is it's a pretty broad curve and just because "average" MTBF = 5 years, doesn't
make someone feel better if theirs is one of the 1% that fails after 6 months,
and doesn't mean that yours might not be one of the 1% that fails at 10 years.

If you keep the temperatures WELL UNDER stock Intel HSF temperatures
for the chip that it'd have at stock speed even if you overvolt / overclock
moderately you're probably overall not hurting your reliability too much.
In practice you may need water-cooling or very high end air cooling to do that though.

If you run the chip AT the same kinds of temperatures Intel's stock HSF would
give at Intel stock speed and Intel stock volts, BUT you're overvolting and overclocking,
there's no question that you'll stress the chip more than the "normal" stock amount,
and it'll fail sooner.

If you run the thing hard 27x7x365 always on that'll take a lot of life away vs.
running it for 4 hours a day or whatever.

If you disable sleep / SpeedStep / Cool_N_Quiet or whatever then that'll take a toll too.

okies.

can i see that bell curve please? id really like to see your sources so i can figure some stuff out.

 

[genec57]

I would love to see something definitive on the subject. There is sooooo much either way. So heavy oc cuts down on life expectancy from 10 years to 7 years - no big deal. To one year - big deal. there is so much unsupported opinion all over the forums that i really wonder if anyone really knows.
Personally, I try to keep my quad under 1.55 vCore and 70c. If I could see evidence that this would likely destroy my chip within three years I might reconsider.
What I do see a lot of is posts from oc'ers who say that they have never had a chip failure, regardless.
From all you guys who make the claims either way I would love to see some quantifiable evidence. Anyone????

 

[SerpentRoyal]

An hour or two at 1.5V is safe as long as the temperature is 25C lower than the Tjunction temperature. A good water-cooled rig can absorb up to about 1.6V with a willing CPU. Again, I would rely on C1E and EIST to lower the voltage when it is not needed (ide or moderate load). CPU should last at least 4 years.

 

[MarcVenice]

Let's say you can buy a 2ghz chip for 80$, and a chip at 3ghz for 160$, that's what it's like roughly for AMD. If you can then OC chip #1 to 3ghz, it doesn't even really matter if it dies in 1.5 years, you could just buy another one, for another 1.5 years

It's risk versus reward. If you can't afford to buy a new cpu in a years time, perhaps you shouldn't be taking any chances.

 

[apoppin]

Originally posted by: genec57
I would love to see something definitive on the subject. There is sooooo much either way. So heavy oc cuts down on life expectancy from 10 years to 7 years - no big deal. To one year - big deal. there is so much unsupported opinion all over the forums that i really wonder if anyone really knows.
Personally, I try to keep my quad under 1.55 vCore and 70c. If I could see evidence that this would likely destroy my chip within three years I might reconsider.
What I do see a lot of is posts from oc'ers who say that they have never had a chip failure, regardless.
From all you guys who make the claims either way I would love to see some quantifiable evidence. Anyone????

there is *nothing definitive* on the subject
-OCing is a gamble ... extreme OCing is an exponentially bigger gamble
--you pay your money and you take your chances .. some chips seem to last forever; other die very quickly
---i would never OC if i couldn't stand to lose my CPU. i don't OC expensive CPUs ... kinda defeats the "purpose" ... otoh, if i kill my $114 e4300 ... i replace it without a tear ... i expect to buy penryn next year anyway.
----What we know:

FACT: heat kills your CPU
--the cooler you keep it the better

FACT: Overvolting shortens CPU life [generally] exponentially faster than simple OC'ing without it
--So, the less overvoltage to reach your OC, the better

FACT: Even a simple OC speeds electromigration
-most of us find this no problem if temps are also kept low

we DID discuss this years ago with PM - an elite member who really knew his stuff working as a CPU engineer for intel and he really did know about OC'ing. Unfortunately this info's details are hidden in my brain and in bookmarks from probably 4 years ago.

 

[CurseTheSky]

"---i would never OC if i couldn't stand to lose my CPU. i don't OC expensive CPUs ... kinda defeats the "purpose" ... otoh, if i kill my $114 e4300 ... i replace it without a tear ... i expect to buy penryn next year anyway."

For some, it's a hobby - taking an already "extreme" processor up to even higher levels. Personally, it's not my cup of tea. Your $1k now will be forgotten in a year or two anyway. Remember the Prescott EE's versus the FX-57's? I think those were the hot models of the time. (I snatched up an X2 4200+ back when dual cores "were a waste," and overclocked it to near FX-57 performance anyway).

 

[Acanthus]

Theres a reason they call it "suicide benching" at xtremesystems

Generally if you overvolt by 10% over stock, and you have decent cooling, youre safe.

Once you go over the .2v mark, youre talking a significantly shorter life, regardless of temps.

Over .4v and youre talking months instead of years for the chips life.

 

[apoppin]

Originally posted by: CurseTheSky
"---i would never OC if i couldn't stand to lose my CPU. i don't OC expensive CPUs ... kinda defeats the "purpose" ... otoh, if i kill my $114 e4300 ... i replace it without a tear ... i expect to buy penryn next year anyway."

For some, it's a hobby - taking an already "extreme" processor up to even higher levels. Personally, it's not my cup of tea. Your $1k now will be forgotten in a year or two anyway. Remember the Prescott EE's versus the FX-57's? I think those were the hot models of the time. (I snatched up an X2 4200+ back when dual cores "were a waste," and overclocked it to near FX-57 performance anyway).

sure i do ... i had an OC'd NW P4 3.4EE that also nearly matched fx-57 performance - i got it 3 years later for just over $100.

My entire point was to not OC a Proc that you can't stand to lose or can't afford to replace.
--For most OCers it IS to get performance out of a "lesser" CPU ... the really eXtreme guys have liquid nitrogen and CPUs to burn.

 

[bryanW1995]

Originally posted by: graysky
A little voltage translates into a lot of heat. Here is a more detailed analysis of two difference vcore settings and the temps they produce on a Q6600 @ 9x266=2.4 GHz as well as @ 9x333=3.0 GHz. The two voltages I used were 1.112 V and 1.232 V (both of these are the load voltage, the actual BIOS settings were 1.1375V and 1.2625V respectively).

2x orthos ran for 30 minutes and the temperatures were averaged over the last 10 minutes of those runs (well after they stabilized). Room temps was 75-76 °F. Notice that the difference in voltage is ONLY 0.120 V or 120 mV, but this seemingly small difference brought the load temps up by an average of 6-7 °C per core!

Run1 (9x266 @ 1.112 V), Average temps (°C): 51,52,50,50
Run2 (9x266 @ 1.232 V), Average temps (°C): 57,58,57,57
Differences (°C): +6, +6, +7, +7

Now if I add a faster FSB, they increased further:

Run3 (9x333 @ 1.232 V), Average temps (°C): 61,61,60,60
Differences from lowest voltage (°C): +10, +9, +10, +10
Differences from same voltage (°C): +4, +3, +3, +3

That is good stuff. Too often on here we talk about what we heard or things that we half-remember from last year. Graysky gets out and does it.

 

[cmdrdredd]

How many people here that overclock will see their cpu die before the usefulness of that CPU is worn out?

Here's what I mean. I have an old P4 2.6c rig with a P4P800 Mobo. I overclocked it to 3.2Ghz. This thing has got to be going on 5 years old now. So the question is, is it still a fast CPU? Not to me. Is it still working? Yes.

So the point of all this to me is. You will likely upgrade the CPU or the entire system before your CPU dies because of some overclocking as long as you 1) keep it cool 2) don't go too extreme.

 

[apoppin]

Originally posted by: cmdrdredd
How many people here that overclock will see their cpu die before the usefulness of that CPU is worn out?

Here's what I mean. I have an old P4 2.6c rig with a P4P800 Mobo. I overclocked it to 3.2Ghz. This thing has got to be going on 5 years old now. So the question is, is it still a fast CPU? Not to me. Is it still working? Yes.

So the point of all this to me is. You will likely upgrade the CPU or the entire system before your CPU dies because of some overclocking as long as you 1) keep it cool 2) don't go too extreme.

of course ... you are preaching to the choir ... that IS why it is so popular here
- the vast majority of us OC'ers are successful - for years [except for the unlucky ones or ones that took it way too far too fast - and then you hear all about it - for years later - that OC'ing is "dangerous"]

i'd say to the new OCer, use common sense and be conservative until you are sure of what you are doing all the while carefully monitoring temps.

 

[cmdrdredd]

Originally posted by: apoppin

Originally posted by: cmdrdredd
How many people here that overclock will see their cpu die before the usefulness of that CPU is worn out?

Here's what I mean. I have an old P4 2.6c rig with a P4P800 Mobo. I overclocked it to 3.2Ghz. This thing has got to be going on 5 years old now. So the question is, is it still a fast CPU? Not to me. Is it still working? Yes.

So the point of all this to me is. You will likely upgrade the CPU or the entire system before your CPU dies because of some overclocking as long as you 1) keep it cool 2) don't go too extreme.

of course ... you are preaching to the choir ... that IS why it is so popular here
- the vast majority of us OC'ers are successful - for years [except for the unlucky ones or ones that took it way too far too fast - and then you hear all about it - for years later - that OC'ing is "dangerous"]

i'd say to the new OCer, use common sense and be conservative until you are sure of what you are doing all the while carefully monitoring temps.

QFT

 

[Diogenes2]

What's the worst that can happen ?

CPU dies ..

Solution ?

Buy another one ...


I don't ever remember seeing a thread where an experienced overclocker thought that overclocking killed
their CPU ..

 

[CTho9305]

Originally posted by: genec57
I would love to see something definitive on the subject.

Manufacturers do extensive analysis to predict lifetimes under all sorts of conditions. The problem is that nobody outside of industry is willing to buy a decent sample size of CPUs and do meaningful experiments and keep them running for a couple years. It's no fun, and requires a considerable investment of time, storage space, and money. And, of course, once your study is done, people will write it off as meaningless since it was done with ancient 2-3 year old CPUs . It's much more fun to use unscientific anecdotal evidence and keep propagating what are effectively myths.

Originally posted by: SerpentRoyal
An hour or two at 1.5V is safe as long as the temperature is 25C lower than the Tjunction temperature. A good water-cooled rig can absorb up to about 1.6V with a willing CPU. Again, I would rely on C1E and EIST to lower the voltage when it is not needed (ide or moderate load). CPU should last at least 4 years.

Personally, I think running a 65nm CPU at 1.6V is insane no matter what your cooling is.