Benifits of overclocking?

[civix]

What is overclocking?
What are its benifits?
Whats are its downsides?

[MrWizard]

Originally posted by civix
What is overclocking?
What are its benifits?
Whats are its downsides?

1) What is overclocking?

The process of making a computer component run at a faster than factory specified speed.

2) What are its benifits?

It will process instructions faster, thus improving performance.

3) What are its downsides?

Well anytime you change a factory setting there can be trouble. Its like putting racing stuff on a regular car. Sure it will be faster but thats faster than factory specified so it could damage components in time. May cause overheating etc etc. I personally never do this because of this reason, I spend hard earned money of my parts and I don't want them to die pre-maturally.

Nvidia graphics cards and any cpu's are notorious for being overclocked.

[kevinalm]

>>What is overclocking?

A really bad idea.

>>What are its benifits?

Makes your computer faster for a while.

>>What are its downsides?

Extra crispy cpu among other things.

:D

Seriously it's not something i'd recommend, for the reasons MrWizard stated. MrWizard's explaination is very good by the way. Something I would add is that overclocking increases random errors. Pushing up the clock speed narrows the design margin thus reducing both physical reliability (as in the cpu frying) and computational reliability. I don't like the trade off myself. A few percent gain in performance can get very expensive quickly.

[MrWizard]

Civix explanation? What did he explain??

Oh yeah, I forgot it can also cause computational errors. Thanks for pointing that out! When the processor heats up past a "reasonable" temperature it can produce errors.

[dP munky]

wizard you know he's talking about you.....dont be so modest :)

[kevinalm]

MrWizard

Sorry about that. I was actually referring to your explaination. I'll edit my post right away.

It's not only the heat. You start messing indirectly with various apects of system timing for example. But one of the most objectionable is cpu heat induced errors. The "blue screen of death" is kind of hard to miss.

[TravisS]

Overclocking can be a good idea IF you are well prepared for it. To overclock properly can be a tricky thing.

On the gamers HQ board for mad onion are lots of people who overclock to the extreme. I'm talking 3+ Ghz out of a 1.6 Ghz P4, 4+ Ghz from a 2.4 Ghz P4 (and a few AMD in there too ;)), etc... Lots of people who push their FSB (front side bus) up to and beyond 200 MHz.

IF your components can handle it, and IF you have the proper cooling this will not reduce the life of your computer beyond the already short obsolescence lifespan of maybe a few years. A CPU is designed from the factory to last approximately 10 years, most last longer. If you overclock properly you may not shorten this lifespan by much, maybe by 3 years.

It's all about heat. Not just CPU, but also all PCI (except nForce 2 motherboards), AGP, RAM, etc... basically all components that are in one way or another connected to the FSB. Watercooling helps the CPU, and case fans help everything else. There are a lot of people who's overclocked systems run cooler than my default AMD system.

[MrWizard]

Originally posted by kevinalm
MrWizard

Sorry about that. I was actually referring to your explaination. I'll edit my post right away.

It's not only the heat. You start messing indirectly with various apects of system timing for example. But one of the most objectionable is cpu heat induced errors. The "blue screen of death" is kind of hard to miss.

No problem :) I thought I was missing something, ha ha.

TravisS:

Proper cooling and such helps prevent damage to components but does not garauntee anything. Sometimes its a matter of Russian Roulette on if something will break. My point is, when you start tinkering with things like that you are running a risk period. Maybe if you overclock is small no big deal but one day you will get greedy and burn up your cpu. It seems like such a quick way to get speed at no cost but believe there is a great cost associated with it. So maybe people are having more luck with it nowaday's. I'm just saying be careful.

[TravisS]

Yeah, it's risky business, no doubt about that ;)

There's a lot that goes into it. Even the same brand/speed processor will overclock differently, depending on things such as its stepping. Plus, there's always that "I want to go faster" problem :)

My GeForce 4 is overclocked, and runs overclocked 24/7. The rest of my system on the otherhand is not. I upgrade video cards way more often than CPU's, so I don't care about a shortened lifespan on that, plus I've taken measures to ensure it's safe.

Basically, it comes down to: Overclock if you're well prepared for it, are ready to test intesively for stability, and have the money to burn if something goes wrong.

[dP munky]

cant cooling systems alone get pretty pricey when overclocking though?

[moi]

overclocking is overall a good thing. you must be careful and always ensure proper percatuions, esp with reguard to temperature. if you can't keep your CPU die at a reasonable temperature, turn down the speed. my everyday machine is a duron 600 (1.60V) @ 900mhz (1.75V). temperature is usually around 36-38 degrees C; never had a problem with it yet.

[MrWizard]

Originally posted by moi
never had a problem with it yet.

Famous last words :)

[Fountain]

Yeh, to me it seems too much messing.

Why spend time over clocking etc-just buy the faster chip!

AMD chips are not expensive remember?:rolleyes:

[TravisS]

Athlon XP 2000+ and below = dirt cheap

Athlon XP 2100+ and above = expensive

My 2200+ cost me $200 USD. A 2000+ would have been about $90. I wish they had some of those in stock when I went to upgrade :(

[Sayeh]

overclocking is overall a good thing.

No, it's not. It shows a basic misunderstanding of discrete circuitry and motherboard design. Although a chip might be able to operate at a higher-clock rate, it doesn't mean everybody should do it. It is a custom tweak reserved for the knowledgeable, the rich, or the foolish.

When people think about clockspeed, they think of increased cycles per second, but they don't understand _how_ that is achieved. It is achieved by running increasing amounts of current through the chip.

The reason it gets hot is because the physical material of the traces and the silicate substrate are resisting electron flow. It's literally frying the chip. It will always shorten the life of the chip unless the temperature rise falls within an envelope originally designed for that chip.

Adding fans or other cooling devices may save the chip, but don't take into account that the motherboard itself was designed to run at a certain clock rate-- traces on the board are designed at specific lengths to support certain clock rates.

If you push the clockspeed of the processor, the mobo itself may not have high-enough quality materials (traces, layers, etc) to support the added current. In which case anomolies will appear that are almost impossible to find-- memory errors, hangs, crashes, corrupted data... or worse (a volcano in a chip)...

Just be careful and remember overclocking isn't for everyone. If you sweat just changing a NIC Card, HDD, or Display Adapter-- leave your CPU alone.

[kevinalm]

>>The reason it gets hot is because the physical material of the traces and the silicate substrate are resisting electron flow. It's literally frying the chip.

Partly true. In order to overclock it is usually necessary to raise cpu supply voltages above specs, which will directly raise power disapation. What is not commonly known is that the main cause of the added heat is simply the increased clock rate. Digital circuits heat during the transistion period between 1 and 0. (Digital circuits disapate little at logic high or logic low. It's in between that heating occurs.) Raising the clock increases the number switches per second and thus total device disapation. A minor technical point I always thought interesting.

[eats only heads]

here are some articals about over clocking.

http://arstechnica.com/tweak/oc_cooling.html

[Shadow]

http://www.TomsHardware.com

[Sayeh]

Partly true. In order to overclock it is usually necessary to raise cpu supply voltages above specs, which will directly raise power disapation. What is not commonly known is that the main cause of the added heat is simply the increased clock rate. Digital circuits heat during the transistion period between 1 and 0. (Digital circuits disapate little at logic high or logic low. It's in between that heating occurs.) Raising the clock increases the number switches per second and thus total device disapation. A minor technical point I always thought interesting.

No. Allow me to explain the rest of the _real_ details.

Actually, what you are failing to understand is that in order to raise the cycle rate, it requires higher voltage. The simple reason is that as cycle rate increases, it becomes more difficult to digitally force a waveform to change from a positive voltage (in this case 2.5v or perhaps 3.7v or even 5v) to neutral (or negative in some cases) and back again. It's a square wave.

In electricity, electrons only travel on the surface of a conductor. They do not travel through the center. Thus, as you raise the voltage, the diameter of the conductor (a trace) becomes insufficient to handle the current capacity and resistance causes heat to be generated.

Dissipation is an effect that occurs after the heat has already been generated. Keeping a chip cool doesn't negate the loss or eliminate the resistance. It merely hides the symptoms and prevents a physical materials breakdown.

[kevinalm]

>>Actually, what you are failing to understand is that in order to raise the cycle rate, it requires higher voltage. The simple reason is that as cycle rate increases, it becomes more difficult to digitally force a waveform to change from a positive voltage (in this case 2.5v or perhaps 3.7v or even 5v) to neutral (or negative in some cases) and back again. It's a square wave.



Sorry, but what you are missing is that I'm talking rise times and duty cycles. And it's NOT a square wave. It's quite true that the necessary voltage boost increases dissapation. (As I stated before.) But the major effect is subtler than that.

A transistor in the on state heats very little. (power dissipates in load) A transistor in the off state heats very little. (no current, no power to dissapate). It's in the intermediate state that a transistor heats. Since the switching time is more or less constant in logic circuits, heating is strongly dependant on frequency. At very high frequencies things get even worst due to the transistors never fully reaching cutoff or saturation, which creates "sneak" paths for the current to ground without ever leaving the chip to the load.



>>In electricity, electrons only travel on the surface of a conductor.

Just plain wrong. What happens is that when you raise the frequency from 0 hz up the current tends to be constrained to a layer on the surface of the conductor. Dc travels through the entire body of the conductor. After about 30 Mhz skin effect has done it's worst. Once you get into the 100Mhz region things don't change that much.


What's really important though is that when you overclock, things get hot very quickly.

[Sayeh]

Sorry, but what you are missing is that I'm talking rise times and duty cycles. And it's NOT a square wave.

Okay, okay-- let's start this over. First let me say that I am an EE. I helped develop Intel's 4004 CPU. I've worked on many others. Digital electronics is not a mystery to me at all.

I have tried to provide a slightly simplified view of what's going on because most of the details you've mentioned are meaningless to the "concept" of why things get hot, to most people.

In the first place, Direct Current (that's DC to you) is run through the processor at a specific, fluctuating voltage. It fluctuates from let's say 0v to 3.5v and back again, endlessly. The number of times this fluctuation occurs per second is the Processor Frequency. Electrically speaking, this is a Hertz rating.

In a 1KHz CPU, it would change the voltage state from 0v to 3.5v and back to 0.v again ideally 1000 times per second.

The reason the _SQUARE_WAVE_ waveform is important to understand here, is because it requires current to change the voltage state from 0v to 3.5v, or vice-versa. In digital electronics, this change must be nearly instantaneous. As such, on a scope, a square-wave is formed. AND IT IS IN THAT CHANGE where the "loss" is generated which becomes heat.

Here's why--

The more times you require that nearly instantaneous state-change, the more current it requires to make that change.

A CPU is built with certain expectations-- namely, they don't expect the chip to have more than a certain amount of current run through it. That maximum amount of current determines the physical characteristics of the components in the chip.

In electronics, if you run excessive current through a component, that excess current becomes a loss. In digital circuitry all such losses result in heat. This is a physical materials/characteristics issue.

You talking about "rise-times" and "duty-cycles" is the "how", not the what. I'm explaining the physical what.

[thedumbmutt]

lol, your posts are amusing when you get mad at someone, you just call them stupid and tell them to go away, anyone remember the president clinton thread?

[kevinalm]

Sayeh, re your last post. If you look back over the thread, you'll see that's exactly what I was saying. I was using simplified language for a more general audiance. I perhaps could have been clearer.

I still maintain there is no such thing as a square wave. Fourier kind of rules that out. ;) I'm an E tech myself.

[eats only heads]

one thing to remember, Many chips you buy are just under clocked versions of faster chips. I heard for example that 4 out of 5 300 mhtz cpu's could be run at 450 mhtzs no problem. This is because intel underclocked them for the sake of the maket. If they just sold 450 mhtzs chips then the prices would drop too fast. None the less you can't run a 450 mhtzs any higher then 450 mhtzs.

[thedumbmutt]

that would ssem to explane why intel can oc without heating up as bad as an amd.

[Sayeh]

I still maintain there is no such thing as a square wave.

True, and I don't really disagree with that (after all, it is an analog world), it's just that we get as close as we can to a square wave. It's sort of like this analogy:

If you are standing 5 feet from Marilyn Monroe, and you keep cutting the distance between the both of you in half, at what point are you close enough for all intents and purposes?

cool.