Overclock.net › Forums › Intel › Intel - General › Can someone explain overclocking to me?
New Posts  All Forums:Forum Nav:

Can someone explain overclocking to me?

post #1 of 21
Thread Starter 
I know what it does, but what are the advantages and disadvantages of over clocking and no overclocking? Also, could someone lead me to a thread about how to over clock?
post #2 of 21
Can you please tell us what CPU your using? That would make it easier for us to help you find the right thread.
post #3 of 21
Thread Starter 
I am getting i5 2500k SB
post #4 of 21
Alright, great. Thank you. Overclocking has both it's advantages and disadvantages. The advantages in overclocking is increased performance and speed, also you could have bragging rights and the earned title as an overclocker. Now, increased speeds depends on your overall setup. If you have an old GPU, then you will see a bottleneck with your GPU. a bottleneck is where one of your components limits the performance of your overall computer. Let's say you have all the latest and greatest sandy bridge stuff, including the Maximus IV Extreme and the I5 2500k. Alright, then you go and get an 8800GT graphics card. What? That is what is called a bottleneck because your CPU is limited by your graphics card. That is why I suggest you balance out all of your components. Now, sorry for getting off topic.

Now for the disadvantages to overclocking. Your CPU will see a decreased lifespan, depending on how far you overclock it. If you were to over clock it to around 5ghz, then your CPU will most likely last 2 years MAX. Also, the higher you clock your CPU, the hotter it gets and without a decent CPU cooler, you can see your chip fry.

Here is a link to Sandy Bridge overclocking:
http://www.overclock.net/intel-gener...uide-p67a.html
post #5 of 21
Quote:
Originally Posted by Weezernation View Post
Alright, great. Thank you. Overclocking has both it's advantages and disadvantages. The advantages in overclocking is increased performance and speed, also you could have bragging rights and the earned title as an overclocker. Now, increased speeds depends on your overall setup. If you have an old GPU, then you will see a bottleneck with your GPU. a bottleneck is where one of your components limits the performance of your overall computer. Let's say you have all the latest and greatest sandy bridge stuff, including the Maximus IV Extreme and the I5 2500k. Alright, then you go and get an 8800GT graphics card. What? That is what is called a bottleneck because your CPU is limited by your graphics card. That is why I suggest you balance out all of your components. Now, sorry for getting off topic.

Now for the disadvantages to overclocking. Your CPU will see a decreased lifespan, depending on how far you overclock it. If you were to over clock it to around 5ghz, then your CPU will most likely last 2 years MAX. Also, the higher you clock your CPU, the hotter it gets and without a decent CPU cooler, you can see your chip fry.

Here is a link to Sandy Bridge overclocking:
http://www.overclock.net/intel-gener...uide-p67a.html
CPU life is dependent on mostly voltage, not frequency.
Sexy Sandy
(15 items)
 
  
CPUMotherboardGraphicsRAM
Intel Core i7-2600K Gigabyte Z68X-UD5 MSI GTX 580 LIGHTNING G.SKILL Ripjaws X Series 8GB (2 x 4GB) 
Hard DriveOptical DriveCoolingOS
Crucial M4 128GB+Samsung Spinpoint F3 1TB+Seaga... LITE-ON DVD Burner Noctua NH-D14 Windows 7 64-bit 
MonitorPowerCaseAudio
BenQ xl2410t Corsair 850HX Cooler Master HAF-X  Asus Xonar DG 
  hide details  
Reply
Sexy Sandy
(15 items)
 
  
CPUMotherboardGraphicsRAM
Intel Core i7-2600K Gigabyte Z68X-UD5 MSI GTX 580 LIGHTNING G.SKILL Ripjaws X Series 8GB (2 x 4GB) 
Hard DriveOptical DriveCoolingOS
Crucial M4 128GB+Samsung Spinpoint F3 1TB+Seaga... LITE-ON DVD Burner Noctua NH-D14 Windows 7 64-bit 
MonitorPowerCaseAudio
BenQ xl2410t Corsair 850HX Cooler Master HAF-X  Asus Xonar DG 
  hide details  
Reply
post #6 of 21
Thank you for correcting me. But also, you have to remember, the higher the clock speed the more voltage you need in most situations.
post #7 of 21
Thread Starter 
I am planning on getting gtx 570. I am planning on building a a great gaming computer. When I have all my cash I will start looking for finals products, I have an idea of what I want but not for sure.
post #8 of 21
Advantages: There's slight advantages here & there, but the important advantage is the performance boost. The performance boost effects everything, really.

Disadvantages: Heat, time consuming, expensive (if you wish to extreme overclock), degradation (again, extreme overclocking).
post #9 of 21
I'll have to disagree with the above posters that running a chip at 5.0ghz will cause it to fail in 2 years max. Why overclocking damages a CPU is a bit more complicated.

Why does OCing dmg a CPU?
Explaining this requires delving into a bit of Quantum Mechanics, but I'll keep it simple. You'll just have to take my word for some of the concepts though =P

Normally, electrons stay around their atom's and don't go wandering off. So in a CPU, they'll stay in one transistor and not move to others. However, at the quantum level (objects smaller a quanta which is 6.626068 × 10-34 m2 kg / s aka planck's constant) it's actually possible for electrons to escape from energy wells when given enough energy, even infinitely deep ones, it's just very uncommon. As a result of this, in a process known as quantum tunneling, electrons can pass through solid matter and be ejected out the other side.

Now, a transistor in a CPU is made from alternating + and - doped and undoped silicon. Once in a while, an electron will escape and bury a couple atoms into an adjourning transistor, and if this happens enough times, eventually all the way through to the adjourning transistor before coming back to it's orbit.

Keep doing this and eventually an electron doesn't come back, but stays attached to an atom in the adjourning undoped section of silicon. Over time (usually years), this tunneling causes a hole to be formed between two adjourning transistors and allows free electron flow.

This bypasses the "gates" between the transistors and as a result, the computer will misread this resulting in an error. Open and closed gates are how a CPU determines if something should be read as a 1 or a 0.
This process is called silicon degradation and eventually results in a complete CPU failure.

Now, as to where overclocking comes in.

If you know about electron orbital theory, the more energy an electron has, the more likely it is to leave it's orbit and tunnel. IE if your CPU is running hot, or has a considerably higher voltage going through it, electrons tunnel in much higher numbers. As a result, the more you OC, the faster you make those tunnel which cause silicon degradation.


In addition, if you increase the voltage enough, you can actually physically destroy the silicon lattice of the gates within a processor. Basically what this is think of a guy throwing a ball at a wood door. If he throws it at 20mph it'll probably just bounce off. However, if you throw it at 80mph, you might just break right through it. Increases v does a similar thing with electrons, shooting them through the CPU with greater force.

Now, on to OC and Heat
In a CPU boosting F, has a very minor, almost insignificant heat increase.

It's v increase that dramatically increases heat.

Power Dissipation = PD in Watt
Voltage = Volt
Freq = Hz
C= Capacitance in Farads

Total PD in Watt = C x F x V^2
As C doesn't change (ok it technically does, but for the sake of keeping the math simply we can assume it doesn't)

If you actually plug in numbers and graph the function, the heat increase due to a freq increase is minute compared to the heat increase from a v increase, as one increases exponentially, the other linearly.

Indeed, the more you increase the V, the less the F part of the equation is relevant to the total temp.


Looking at real world data, look at the power usage increase in Tom's i5 efficiency article.
http://www.tomshardware.com/reviews/...cy,2500-7.html


Each bump was a constant 10mhz clock speed increase, but due to the exponential nature of the voltage increase contribution to PD, the graph is not linear, and power usage does not increase until you start seeing large v increases.

Power usage directly translates into heat.

As for actual temps, it's more complicated than purely based on power dissipation
Cpu temperature = (Total PD in Watt) x (HSF's Thermal Resistance in
C/W) + (Ambient Temp in Celcius)

For comparison purposes the resistance and ambient can be considered constant (technically not true once again, as resistance changes slightly with temp, and ambient increases with more heat output).

In your specific case, the answer is not so much what clock speed you reach while OCing, but how much v increase you'll need to attain it. If there is no v increase, life of the CPU will be minimally impacted.

There is no easy way to tell how each chip is affected as due to imperfection in the manufacture process, the degradation rate vs v or f graph would be unique to each chip.

However, a big factor is temp of the CPU and v used, both of which increase the rate of electron tunneling. A 5.0ghz OC at below ambient and say 1.4v will last much longer than a 5.0gz OC at 80C and 1.5v.

To get some actual approximations, you'll have to consider the fact that Intel designs its CPU's to last ~10 years at the Tcontrol value (was mentioned by Intel several years back, not sure if the current gen of CPU is much diff), which is the temperature they strive to keep the CPU at. This temp is MUCH higher than most enthusiasts will tolerate for their CPU's.

I'm not sure exact value for sandy bridge, but it's ~68C. It's somewhere in the thermal specifications data sheet if you want to dig for exact value.
http://download.intel.com/design/pro...nex/324644.pdf

Now, assuming you cool you CPU to the Tcontrol point, as long as their is no v increase, the lifespan will be minimally impacted. The more voltage you add, the shorter the lifespan is. However, I doubt even a 1.5v or higher OC if kept at the Tcontrol point will last less than 5 years based on what I've seen from Intel's own data. For most enthusiast's 5 years is more than they will use a CPU for.

For some more details, here's the powerpoint of a Tcontrol presentations Intel gave a few years back.
http://www.mediafire.com/?tz9tdjkbxek5gc2
Alduin-WIP
(22 items)
 
  
CPUMotherboardGraphicsGraphics
i7-2600k GA Z68XP-UD4 MSI 6950 2gb Twin Frozr III MSI 6950 2gb Twin Frozr III 
RAMHard DriveHard DriveHard Drive
G Skill Sniper Crucial M4 256GB Spinpoint F4 2TB Spinpoint F4 2TB 
Hard DriveCoolingOSMonitor
Spinpoint F4 2TB Thermalright HR-02 Windows 7 Professional 64 bit Dell U2311H x3 Portrait Eyefinity 
PowerCaseOtherOther
Corsair AX750 Silverstone FT02 Sleeving, acrylic, lighting and whole buncha ot... Laser Cutting and Engraving 
  hide details  
Reply
Alduin-WIP
(22 items)
 
  
CPUMotherboardGraphicsGraphics
i7-2600k GA Z68XP-UD4 MSI 6950 2gb Twin Frozr III MSI 6950 2gb Twin Frozr III 
RAMHard DriveHard DriveHard Drive
G Skill Sniper Crucial M4 256GB Spinpoint F4 2TB Spinpoint F4 2TB 
Hard DriveCoolingOSMonitor
Spinpoint F4 2TB Thermalright HR-02 Windows 7 Professional 64 bit Dell U2311H x3 Portrait Eyefinity 
PowerCaseOtherOther
Corsair AX750 Silverstone FT02 Sleeving, acrylic, lighting and whole buncha ot... Laser Cutting and Engraving 
  hide details  
Reply
post #10 of 21
I'd agree that running 5ghz would last a lot longer than 2 years... unless you were putting 1.5volts through it 24/7 it wouldn't be affected too much.

banthracis' post was very informative, and a very interesting read... +rep. it's funny that our cpu's are affected "at the quantum level"
My System
(13 items)
 
  
CPUMotherboardGraphicsRAM
2500k @ 4.5/4ghz depending on weather and/or mood P67 SABERTOOTH B3 XFX HD5850 @ 820/1125 2x2gb g.skill ripjawsX 1600mhz 
Hard DriveMonitorKeyboardPower
64gb Corsair SSD, 1tb Samsung F4 28" Hanns.G 1920x1200 Microsoft SideWinder X4 600w OCZ gameXstream2 
Mouse Pad
Razer Sphex 
  hide details  
Reply
My System
(13 items)
 
  
CPUMotherboardGraphicsRAM
2500k @ 4.5/4ghz depending on weather and/or mood P67 SABERTOOTH B3 XFX HD5850 @ 820/1125 2x2gb g.skill ripjawsX 1600mhz 
Hard DriveMonitorKeyboardPower
64gb Corsair SSD, 1tb Samsung F4 28" Hanns.G 1920x1200 Microsoft SideWinder X4 600w OCZ gameXstream2 
Mouse Pad
Razer Sphex 
  hide details  
Reply
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Intel - General
Overclock.net › Forums › Intel › Intel - General › Can someone explain overclocking to me?