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Underclocking = Unsafe, depending on voltage

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May 4, 2008 6:26:41 PM

I decided to bring in a new thread to bring my side of the argument against iluvgillgill. ;) 

I googled about underclocking, and there's not much to it. Go google overclocking and they list all the benefits and dangers.

So here's my thinking process:

The NB and FSB has a "normal" voltage of 1.3V, or at least assume this for now. As you know, 1.3V is plenty for 333MHz, perhaps even 400MHz, so we can say it's a little too much voltage at 266MHz, but it's fine nonetheless and hardly dangerous. However, if we cold lower the voltages to, say 1.2V or so, it's probably better.

Now we all know overvolting is undesirable, perhaps damaging. Take a Q6600 clocked at stock speeds for example. Setting the vcore to 1.5V when really only requiring 1.2V at 2.4GHz is damaging to the cpu, even though it can handle it. Thus, is it not damaging if you set it to 800MHz at 1.2V, when it really requires .8V?

As for damaging, whether it be truly damaging or only slightly damaging, it's "dangerous" according to the manufacturer, since it's out of the specs of the motherboard.

I have gotten quite interested in this, so does anybody have any links that proves anything? Preferably from someone who understands this field of study, and not some hardware enthusiast.

More about : underclocking unsafe depending voltage

May 4, 2008 6:37:46 PM

you can test... :p 
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May 4, 2008 6:54:41 PM

I thnk that logic is off.

It would be definitely better if you lowered the voltage, but I don't think it would be damaging to leave it at stock if you underclock.

In my opinion, voltage and speeda re unrelated. Well, not really. But what I mean is that if something is able to run at a certain voltage, it shouldn't matter what speed it is going. it's just that it's able to handle that voltage.

The damage of the voltage is not related to the speed you are running. With your logic, making a cpu run faster will let you raise the voltage higher without problems, as long as it is proportional to the speed of the processor.

I don't know, it's kind of hard to explain. But I guess I mainly think that while lowering voltage is good for a component, it is still rated for a certain voltage, and will run fine within whatever voltage the manufacturer says it can, regardless of how slow the component is.
May 4, 2008 7:05:04 PM

That I understand. If the manufacturer rates it at a certain range of voltages, it's fine, but only for that certain range of frequency, am I right?

So going lower than the recommended frequency is damaging, at least according to the manufacturer. Not that it is truly damaging.
May 4, 2008 7:19:19 PM

No, because what I am saying is that the voltage doesn't have to do with the speed. It only does if you try to make it go faster. It is definitely helpful to undervolt if you lower frequency, but I don't think it is damaging to leave it normal.

But really, I don't have any evidence or proof. So I suppose you could be right. I'm just basing this on what I think.
May 4, 2008 7:24:36 PM

Nor do I have any evidence or proof. I could just very well say there's no harm done, after all, not many people underclocks (not counting speedstep).

Besides, in a OCing community, I'll bet everyone will say it's safe to UC.
a b K Overclocking
May 4, 2008 7:38:44 PM

Quote:
That I understand. If the manufacturer rates it at a certain range of voltages, it's fine, but only for that certain range of frequency, am I right?


Not that I'm aware of. The chips are rated for voltage X, they are then tested to see what frequency they can get. Lets say AMTel has 100 chips roll off the line. They are all made at the same time, and have the same insides. When AMTel designed the chips, they know that 1V should be the Vcore, so they are set for 1V. (AFAIK, the voltage would be known when the chip is designed.) Lets say that 10 of the chips are able to run at 4GHz with a Vcore of 1V, these will be sold as their Uber chip. Another 15 can run at 3.6GHz. This is the practice of binning.

Those that were running at 3.6GHz might be able to run at 4GHz, but they would require a voltage bump to do so. (1.2V perhaps...) This is where my knowledge isn't as strong, but I'll attempt to explain. The problem with increasing voltage, other then increasing heat, is that it increases internal damage to the CPU. To much voltage can damage the transistors.

I believe the only problem with to little voltage is the transistors won't be able to work. They won't have the energy needed operate. Just like in my example how 1V wasn't enough for some chips to run at 4GHz. If you underclock, there isn't any harm (that I'm aware of) if you decrease the voltage.
a b K Overclocking
May 4, 2008 9:13:55 PM

Underclocking is not dangerous, I have done it before with my old and new HTPC. If you set the voltage too low you will simply get a BSOD or the system will restart. If that happens simply increase the voltage to the CPU, GPU, or whatever you have underclocked.

For example, with my old HTPC which has an Athlon XP-M, I set the voltage to 1.35v instead of the default 1.45v and the system worked fine.

In my new HTPC, I underclock my X1900XT 512mb down to 196MHz Core and 297MHz Memory using ATITool 0.27. It allows profiles to be set up and also when it detects a 3D application (game) is running it will revert back to default speed. Once the application is ended the GPU drops back down to the low speed I set.

There is also an option to set voltages, but ATITool 0.27 doesn't allow you to save it to a profile, so it must be manually adjusted. I set the VCore to 1.2v (down from 1.45v) and all other voltages to minimum. This drops the GPU's temp from 57C when idle down to 50C with the fan speed set to 22%.

Experiment with voltages by decreasing them incrementally, then test by play a game (for the video card), or running some intensive program like CPUBurn (for the CPU); run one instance for each core and it will put a 100% load on the CPU. If everything is okay, then lower the voltage and test again.

-----------------------------------

EDIT: "underclocked" replaces "overclocked" in the first paragraph.

-----------------------------------
May 4, 2008 10:26:21 PM

4745454b said:
If you underclock, there isn't any harm (that I'm aware of) if you decrease the voltage.

And if you don't decrease the voltage? My argument was the underclock will do harm if the voltage isn't decreased as well. Although it may be able to handle it, I think it'll do more damage than stock speeds.
May 4, 2008 10:30:23 PM

jaguarskx said:
Underclocking is not dangerous, I have done it before with my old and new HTPC. If you set the voltage too low you will simply get a BSOD or the system will restart. If that happens simply increase the voltage to the CPU, GPU, or whatever you have overclocked.

I agree underclocking isn't dangerous, to a certain extent. And by dangerous, I mean more harm than stock speeds. In the case of the motherboard, there is the NB and FSB voltage where you can't go any lower than, say, 1.3v. So, using an extreme example, if I were to use the motherboard at 1MHz FSB, 1.3V will do damage, at least more so than running stock.
May 4, 2008 11:27:15 PM

Evilonigiri said:
I agree underclocking isn't dangerous, to a certain extent. And by dangerous, I mean more harm than stock speeds. In the case of the motherboard, there is the NB and FSB voltage where you can't go any lower than, say, 1.3v. So, using an extreme example, if I were to use the motherboard at 1MHz FSB, 1.3V will do damage, at least more so than running stock.


Clocking a processor lower will not magically make it susceptible to damage from it's rated stock voltage.

There's only two main things that damage a processor. Electron migration due to long term overvoltage. And heat. Neither of those will EVER occur due to underclocking at stock voltage. To clarify overvoltage is when the voltage is set higher then it's rated. 1.6ghz at 1.2v stock is not overvoltage if the processor can run at 2.4ghz at the same voltage.

As far as i know if you increase the clock speed, you increase the power draw. At stock speeds a chip will draw a given amperage. If you overclock it mildly on stock voltage it will draw more amperage. Inversely if you underclock it it will draw less.

In other words, at stock voltage and at stock or lower clockspeeds you will NEVER over/underpower the chip. Thus making it impossible to be damaged by underclocking.

This goes the same for the motherboard.
May 4, 2008 11:38:41 PM

lucuis said:
There's only two main things that damage a processor. Electron migration due to long term overvoltage. And heat. Neither of those will EVER occur due to underclocking at stock voltage. To clarify overvoltage is when the voltage is set higher then it's rated. 1.6ghz at 1.2v stock is not overvoltage if the processor can run at 2.4ghz at the same voltage.

Electro migration occurs in any electrical component. The higher the voltage, the faster the process.

So from what you are saying, a 2.4GHz at 1.3V is okay for 800MHz? What about 500Mhz? 1Mhz? According to my experience, overvolting isn't a good thing, even if the component can handle it.
May 5, 2008 12:05:27 AM

Very true, i should have been more specific. What i meant is that only when overvolting electron migration can become a problem. Instead of like 30yrs later :) 

Quote:
So from what you are saying, a 2.4GHz at 1.3V is okay for 800MHz? What about 500Mhz? 1Mhz? According to my experience, overvolting isn't a good thing, even if the component can handle it.


Absolutely. 1.3v at 2.4ghz vs 500mhz. Temps should decrease due to less current required. And electron migration is unaffected. The only bad thing is it would run horribly slow :) 
a b K Overclocking
May 5, 2008 12:15:20 AM

Quote:
And if you don't decrease the voltage? My argument was the underclock will do harm if the voltage isn't decreased as well. Although it may be able to handle it, I think it'll do more damage than stock speeds.


Is there a reason why you think this way? Perhaps if we understood your thinking we could understand you better. (I don't know anything about the thread you referenced in your first post, nor do I want to get involved with any bickering that might be going on.)

Go back to the example that I gave. Remember that all chips are being made at the same time. Some of the chips can run at 4GHz, while others can only run at 3.6GHz. Some might even be able to only do 3GHz, or 2.8GHz. None of these "lower" CPUs should have the voltage lowered however, as they are only stable at these lower speeds with the normal 1V.

Clock speed/FSB and voltage are not locked or linked in any "real" way. You can decrease one without touching the other. If the chip calls for 1.3V, and you decrease the FSB down to 100MHz, I don't see why you'd HAVE to decrease the voltage. Most people would simply seeing as there is no point in having it that high if the clock speed is that low.
May 5, 2008 12:43:11 AM

4745454b said:
Quote:
And if you don't decrease the voltage? My argument was the underclock will do harm if the voltage isn't decreased as well. Although it may be able to handle it, I think it'll do more damage than stock speeds.


Is there a reason why you think this way? Perhaps if we understood your thinking we could understand you better. (I don't know anything about the thread you referenced in your first post, nor do I want to get involved with any bickering that might be going on.)

Go back to the example that I gave. Remember that all chips are being made at the same time. Some of the chips can run at 4GHz, while others can only run at 3.6GHz. Some might even be able to only do 3GHz, or 2.8GHz. None of these "lower" CPUs should have the voltage lowered however, as they are only stable at these lower speeds with the normal 1V.

Clock speed/FSB and voltage are not locked or linked in any "real" way. You can decrease one without touching the other. If the chip calls for 1.3V, and you decrease the FSB down to 100MHz, I don't see why you'd HAVE to decrease the voltage. Most people would simply seeing as there is no point in having it that high if the clock speed is that low.

My thinking is overvolting something will do more damage than not overvolting. Surely overvolting will do more harm then good?

While you explain through using different cpus with different requirements, I'm looking at only one cpu, all relative to itself. If it can do 4Ghz on 1V, doing something extreme such as 1MHz on 1V is damaging, although perhaps not damaging enough to do any permanent damage.
a b K Overclocking
May 5, 2008 12:50:53 AM

Quote:
My thinking is overvolting something will do more damage than not overvolting. Surely overvolting will do more harm then good?


Correct, over volting is bad. I don't change the voltage for my CPU, and would never raise it above what its set at.

Quote:
While you explain through using different cpus with different requirements, I'm looking at only one cpu, all relative to itself. If it can do 4Ghz on 1V, doing something extreme such as 1MHz on 1V is damaging,


Lets ignore the fact that you can't get a modern CPU down to 1MHz. (even the original 8086 ran at 4.something MHz.) Why is 1MHz @ 1V damaging? 1V was fine for running it at 4GHz, why is it bad now? As I said, perhaps if you can explain why you think this is bad I'd have a better idea of where your coming from.
May 5, 2008 1:09:41 AM

Evilonigiri said:
My thinking is overvolting something will do more damage than not overvolting. Surely overvolting will do more harm then good?

While you explain through using different cpus with different requirements, I'm looking at only one cpu, all relative to itself. If it can do 4Ghz on 1V, doing something extreme such as 1MHz on 1V is damaging, although perhaps not damaging enough to do any permanent damage.


But it's not damaging to underclock, even at that extreme. I'm not sure how else to explain it. Perhaps reading over some electrical basics might help.
a b K Overclocking
May 5, 2008 1:25:36 AM

Any one know what Intel/AMDs standing on underclocking? After all they do void your warranty if OCed :lol:  (Only if you tell them though will they know)
May 5, 2008 1:53:41 AM

Just because you underclock, and the voltage is higher than needed, that doesn't mean it is overvolted. It just means that it is more than it needs to be. Overvolting is more voltage than the stock voltage.
May 5, 2008 1:57:56 AM

Well, I have 2 arguments about why underclocking will cause no harm.

1. Take a look at old cpus. A pentium MMX @ 200mhz for example, required 2.8v. Thats an awful lot of volts for such a low frequency. But was it damaging? Not at all. This argument isnt really relevant or important, but its just a thought.

2. Voltage is only pushed through a chip during each clock cycle. Ex. A cpu running at 200mhz at 2.8v, will recieve a 2.8v signal, 200 million times a second. Now lets clock it down to 1mhz. Now, it recieves a 2.8v signal, 1 million times a second. The same amount of voltage is being applied less frequently. Thus, it is impossible to do damage to the cpu in this way. Sure, it may not be necessary to have it at 2.8v, but given this example, it is doing no more than 200x less damage to the cpu per second, than running at stock speed.
May 5, 2008 4:20:48 AM

The voltage isn't directly correlated with the clock speed. If you have 1MHz at 1v (we'll call that stock voltage), it is still running at the 1v that AMTel (lmao, I love that..) specified their chip to run at. Just because it is moving slower doesn't mean that it can handle any less voltage. It just doesn't need it.

I heard this analogy somewhere else, so I by no means claim it, but think of voltage as food to feed a construction worker. Give give the worker too little food, he is unable to do his job, what with the starvation and all. Too much food, he still does his job just fine, he just doesn't require that much food to get the job done. His belly fat is higher temps.
May 5, 2008 5:02:37 AM

lcaley said:
I heard this analogy somewhere else, so I by no means claim it, but think of voltage as food to feed a construction worker. Give give the worker too little food, he is unable to do his job, what with the starvation and all. Too much food, he still does his job just fine, he just doesn't require that much food to get the job done. His belly fat is higher temps.



That's a really good analogy. I was trying to think of one earlier, but I couldn't.
May 5, 2008 5:05:52 AM

EDIT: Mistaken double post.
May 5, 2008 5:13:33 AM

Thanks lol, I thought so too when I heard it.
May 5, 2008 6:00:06 AM

evilonigiri how many people does it to take to to agree with me that running stock voltage but underclock will NOT cause any harm to any part of the computer system?its been 2 thread from me and you and you still not agree with not only me.but every single one in here.

say to yourself isnt what i told you is the same as what the other guys is saying?huh?

or do you want to ring up Intel and every motherboard maker to comfirm this?
a b K Overclocking
May 5, 2008 9:02:41 PM

iluvgillgill said:
evilonigiri how many people does it to take to to agree with me that running stock voltage but underclock will NOT cause any harm to any part of the computer system?its been 2 thread from me and you and you still not agree with not only me.but every single one in here.

say to yourself isnt what i told you is the same as what the other guys is saying?huh?

or do you want to ring up Intel and every motherboard maker to comfirm this?

Hmm... now that's an idea. :D .
May 8, 2008 8:50:16 AM

lol I'm gonna have to jump on the "disagree with evil" band wagon as well...

The overall logic as explained thus far is flawed...

Overclocking and Overvolting require an addition of some sort, so once you exceed that threshold bad things happen. I'll use a similar analogy as previously mentioned, but one I just randomly created... hopefully it will make sense!

--- Think of a 12 ounce coffee mug... You can pour 12 ounces of blazing hot coffee into this mug... adding extra (overclocking/overvolting) will result in spillage which wastes coffee, and you can potentially get burned (damage to cpu and components)

Underclocking and undervolting require that you subtract from the base requirements.

--- Same 12 ounce coffee mug... You can poor 12 ounces of hot coffee... however since it's 8PM and you don't want to stay up all night, you decide to only poor yourself 6 ounces... there's no spills, no personal injuries... the only result is that you "wasted" the additional 6 ounces of space in that coffee mug...

anyway, the latter explanation demonstrates the following: if you underclock and keep the default voltages... you are wasting energy, nothing more. If you underclock AND undervolt, you are being conservative, and saving energy as well... but at the cost of wasting "space" since the system is clearly capable of more.
May 8, 2008 10:52:35 PM

I was expecting that no one would be agreeing with me, after all I'm basing this off my knowledge and nothing else.

Anyways, I'll attack this from a different point of view: Underclocking loads is out of Intel's spec, just like Ocing is. I would assume out of spec settings are "dangerous" and thus voids warranty, so underclocking is not entirely safe.

We should ring up Intel and see, really. Or we can debate this forever. After all, I have to maintain my "Master-de-bater" title. :sol: 
May 8, 2008 11:16:23 PM

no it still doesn't imply "dangerous". Intel's undervoltage specs no doubt reflect the minimum requirement for the CPU to operate, at all. If you go below their minimum, the cpu simply will not function.

This is no different then saying that a 60W lightbulb installed in a lamp that provides only 30W will be damaged... not true... it will simply be less bright, or not turn on at all.

May 10, 2008 2:37:32 AM

redzoneos said:
This is no different then saying that a 60W lightbulb installed in a lamp that provides only 30W will be damaged... not true... it will simply be less bright, or not turn on at all.

Actually, that's dangerous. There's a risk of catching fire doing that. There is a reason why the manufacturers of a lamp company places a sticker that reads "Warning: To reduce the risk of fire, use 60W or smaller,120v, type A bulb" even though it can do 100W. So putting a 60W bulb on a lamp that provides 30W isn't a good idea and probably quite dangerous.

Anyways, I'll ask this one final question: Is a default Q6600 being harmed more at 1MHz @1.35V or at it's stock specs (2.4GHz @1.35V)? I don't care if the "damage" is infinitesimal or not.
May 10, 2008 12:01:33 PM

you are talking extreme now.no motherboard will allow you to run any cpu at 1mhz.the lowest is 100mhz X6.and even run at 1.35v it wouldnt be harmful because an SO MANY people has pointed out its still running on manufacture default voltage which is a safe voltage.and you will just end up waste energy and produce unneccessory heat.
a b K Overclocking
May 10, 2008 12:07:00 PM

1.35v = 1.35v. Again, AFAIK, the frequency doesn't matter. What you need to be worried about with voltage is extra heat, and speeding up electron migration. If you go to low on the voltage, the transistors won't have enough power to turn on or off. (someone posted something about .85v being the lowest "approved" voltage for modern Intel CPUs.)
May 10, 2008 8:42:12 PM

iluvgillgill said:
you are talking extreme now.no motherboard will allow you to run any cpu at 1mhz.the lowest is 100mhz X6.and even run at 1.35v it wouldnt be harmful because an SO MANY people has pointed out its still running on manufacture default voltage which is a safe voltage.and you will just end up waste energy and produce unneccessory heat.

Just because everyone thinks that way doesn't mean it's right. I'm looking for the right answers, not what everybody thinks. Of course there's the possibility that everybody might be right, so I'll stand neutral on this from now on until I find more proof on this matter.

End of debate. For now. :sol: 
a b K Overclocking
May 10, 2008 10:08:43 PM

You still haven't told us why you think this way. If you could put forth a rational reason as to why this might be the case, we would have a better understanding of where your coming from. I've asked this before, but you still haven't answered the question.

Did you notice my last post? 1.35v = 1.35v. Do you see the significance of that statement? (hint: there is no frequency listed in the formula.) To little voltage and the chip won't have enough power to flip the transistors. To much power and the heat gets to high and the gates on the transistors will suffer from electron migration. Again, I never once mentioned frequency "explaining" this. Voltage is one thing, frequency is something else.
May 10, 2008 11:25:28 PM

4745454b said:
You still haven't told us why you think this way. If you could put forth a rational reason as to why this might be the case, we would have a better understanding of where your coming from. I've asked this before, but you still haven't answered the question.

I told you before didn't I? I said overvolting is a bad idea. And frequency IS involved with the voltage. That's how my thinking goes. Just like how higher frequency requires higher voltage, lower frequency needs lower voltage.

4745454b said:
Did you notice my last post? 1.35v = 1.35v. Do you see the significance of that statement? (hint: there is no frequency listed in the formula.) To little voltage and the chip won't have enough power to flip the transistors. To much power and the heat gets to high and the gates on the transistors will suffer from electron migration. Again, I never once mentioned frequency "explaining" this. Voltage is one thing, frequency is something else.

Yes I did read your post. I also understand what you and all the others against me is thinking. It goes like this: The cpu needs at least (let's say) 1V to function. Any lower and it won't work properly. The cpu is also rated up to 1.5V. Any higher is considered damaging. It doesn't matter what the speed is or isn't. Thus I went from my point of view to being neutral, until I can find more evidence for or against myself.
a b K Overclocking
May 10, 2008 11:50:34 PM

You said:

Quote:
My thinking is overvolting something will do more damage than not overvolting. Surely overvolting will do more harm then good?


That has nothing to do with undervolting.

Quote:
I said overvolting is a bad idea. And frequency IS involved with the voltage. That's how my thinking goes.


Correct, you said overvolting is a bad idea, and I'll doubt you'll find anyone who disagrees. (there might be some that do, shave 5 years off of a 10 year CPU, and who would want to run a 5yo CPU? If you take time into consideration, overvolting might make sense...)

Although you refuse to say it, I think I know where the fault in your thinking is. Many people up the voltage to their CPU as they hit higher and higher frequencies. This can help stabilize a CPU if its right at the edge. This isn't the case of more frequency = more voltage, so less frequency = less voltage. I'm not 100% sure why upping the voltage helps stabilize a CPU, although I'm sure it has something to do with helping the transistors switch on and off fast enough at the increased clock speed. Remember that a transistor on the 65nm process can switch (at a lower voltage to) faster then a transistor on the 90nm process. If you want a 90nm transistor to switch as fast as a 65nm transistor, you'd probably have to give it more juice, though why that works I don't know.

If you lower the speed of the chip, you don't need them to switch as fast. Because of this, you can decrease the voltage of the chip seeing as the transistors don't need the "extra" juice. You don't have to however. Simply because you lowered the voltage of the chip doesn't mean the transistors gates are thinner. They are still as wide/thick as they've always been.
May 11, 2008 12:12:42 AM

4745454b said:
Although you refuse to say it, I think I know where the fault in your thinking is. Many people up the voltage to their CPU as they hit higher and higher frequencies. This can help stabilize a CPU if its right at the edge. This isn't the case of more frequency = more voltage, so less frequency = less voltage. I'm not 100% sure why upping the voltage helps stabilize a CPU, although I'm sure it has something to do with helping the transistors switch on and off fast enough at the increased clock speed. Remember that a transistor on the 65nm process can switch (at a lower voltage to) faster then a transistor on the 90nm process. If you want a 90nm transistor to switch as fast as a 65nm transistor, you'd probably have to give it more juice, though why that works I don't know.

I refused to say it? I thought I expressed myself clearly in the examples I gave before. I guess it wasn't clear enough, my apologies.

That is true. My main argument was more voltage than necessary is more damaging than the same voltage with what it requires, no matter how little this damage is. The cpu gets all the current regardless of whether it needs it or not, and so when giving it more than it needs, it is "damaging", even though it can handle it perfectly fine.

4745454b said:
If you lower the speed of the chip, you don't need them to switch as fast. Because of this, you can decrease the voltage of the chip seeing as the transistors don't need the "extra" juice. You don't have to however. Simply because you lowered the voltage of the chip doesn't mean the transistors gates are thinner. They are still as wide/thick as they've always been.

I suppose you are right. And so a 1MHz cpu at 1.3V will have as much "damage" as the same cpu clocked at 4GHz and 1.3V? This I can not comprehend, perhaps due to my lack of knowledge.

Because of my ignorance, I'm withdrawing until I know more. I've been using my common sense (If you can call it that) and experience, along with some "different" thinking and induce what I am arguing about. Can't debate fully without the knowledge you know.
a b K Overclocking
May 11, 2008 5:22:48 AM

LOL, trust me, the knowledge here isn't that much... (not compared to JJ or some others.)

I and the others COULD be wrong, but I don't see how. Intel said the chip was fine at 1.35v. I'm not going to argue with them. With what I know of CPU arch, running 1.35v is fine, it doesn't matter at what frequency you are talking about.

Try to find more info about this. Perhaps Intel has a nice white paper about frequency and speed. Maybe you can show us the true light on this subject. I can't speak for the others, but I'm always willing to learn something new.
!