# A Basic Guide to Overclocking. Read before posting Overclocking Questions



## crjdriver (Jan 2, 2001)

A Basic Guide to Overclocking

Before we begin, there are some things you need to understand;

1 There is NO safe overclocking. All overclocking involves some degree of risk.

2 There is no guarantee of an overclock. Just because someone else was able to OC the same cpu as you have to 3.6gig is NO guarantee you will be able to achieve the same overclock.

3 No overclock is worth anything unless it is a stable overclock. If it is not prime95 stable, it is NOT a stable overclock

4 Do not ask how much you can overclock your XXX cpu. There is no answer to this until you test in a systematic manner. It is like asking how long is a rope? You do not know until you measure it.

5 Do not ask about overclocking your dell, hp, gateway, compaq or other big box system. It is not going to happen. Just about ALL big box systems come with a bios that does not have overclocking options. While it is possible to overclock a dell, etc using software, IMO this is less than worthless. First of all, dells, hp, etc do not have the quality parts necessary for overclocking and second, ALL overclocking should be done manually in the bios/uefi then checked using a stability program.

6 Chuck's rule. Do not overclock with parts you cannot afford to replace.

If you are comfortable with the above, we can continue to attempt a stable OC of your system. The very first thing I would like you to do is read your manual. Become familiar with the bios menus and where settings are located. Each bios [and even each bios revision] can differ as to where settings are located. Giving you detailed instructions on where to find a given setting is just about impossible.

Next issue; the quality of your parts. A stable OC is highly dependent on the quality of your parts. Do not buy an ECS motherboard, cheap ram, or an allied power supply and expect to OC your system. Buying cheap low quality parts and expecting to overclock the system is like buying a Yugo and expecting it to run like a Cadillac.

There are two ways to overclock your system;
1 Raising the cpu multiplier. Works only on cpus that have unlocked multipliers.
2 Raising the FSB [front side bus] Also called the bclk or base clock. This is NOT the preferred method for newer intels. If you have an unlocked intel, then up the multi.

Raising the multiplier will up the cpu speed and leave the rest of the system running at stock speed. Raising the FSB will up the cpu speed as well as the ram speed, the ability of the bus to transfer data, etc ie just about everything in your system. You will need to decide on which method [or combination of methods] you want to use. For my own system, I run a slightly higher multi and up the FSB. The system I am typing this on is an amd fx4350 overclocked to 4.8gig.

To overclock with an unlocked multiplier, find the bios setting for your cpu multiplier and adjust it up one. As an example if you have a 3.0gig cpu and your multiplier is 15, FSB @200, up it to 16. Save settings and restart. This gives you a 3.2gig cpu. Now we need to check the stability. I use prime95 for stability tests. There are other apps as well; you can use AMD Overdrive for AMD systems, or you can use OCCT [Over Clock Checking Tool] In addition, have some type of temperature monitoring software. Most motherboard makers have some type of monitoring software; ie asus probe, gigabyte easytune, etc. If at all possible, use the board mfg's monitoring software. This will provide the most accurate readings.

Start both prime95 and your temp monitor. With prime95 choose the cpu torture test. Let it run for at least 15 minutes. If it is stable with no errors AND your temps are within limits, you can restart and again enter the bios. Up the multiplier again and repeat the test. When you find an error, you can either back-off to a known stable OC or you can up your vcore [cpu voltage] and repeat the stability test. If it fails after upping vcore, you can also adjust the chipset voltage [high end motherboards only] I always recommend that when adjusting either chipset or cpu voltage go up the minimum amount that you can and test.

*Do understand that upping the vcore or chipset voltage carries a very real risk of damaging the cpu or motherboard.*

Once you find a stable setting for your OC, I like to run prime95 for a longer time. Something like 1hr or longer seems to work fine for me. If it runs prime95 for an hour without errors, I would consider it a stable OC.

This concludes the first method of overclocking.

Raising the FSB not only increases the performance of the cpu, it increases the overall performance of your system and IMO is a better method of overclocking. To overclock with this method is a little more involved however it does give better performance. Again read your manual and become very familiar with the bios settings and menus. Restart the system and find your pci or pci-e lock; set it to 100 for pci-e or if an older system using agp, 66/33. Do not leave it set on auto. Note some high end boards have both a pci-e AND a pci lock; again read your manual. If your mb does not have a pci lock, your ability to overclock using this method will be limited. Now find your ram speed and lower it one setting; ie from 1600 to 1333 as an example. This removes the ram from the overclocking equation. Do not worry; your ram speed will increase as we up the FSB. Save all settings and restart; again enter the bios. Find your FSB setting and increase it from its stock setting by 10mzh or so. As an example let's say your stock FSB is 266. Up it to 275 or so; save settings and restart. Let it boot into windows. Start your monitoring software and prime95. Run prime95 for at least 15 minutes. If it is stable with no errors, restart and enter the bios. Again up the FSB by 10mzh or so; save settings and restart. Repeat the stability test. Keep doing this until you find an error in prime95. When you do, you can now either back-off to a stable OC or up the vcore [cpu voltage]. If after upping the vcore you still get errors, you can adjust the chipset voltage as well. The chipset voltage can be adjusted on high end motherboards. As above limit the amount of voltage adjustment to the least the board will allow and test. Once you find a nice stable OC, then run prime95 for an hour or so to make sure it is stable. Some systems like AMD use a HT or hyper transport bus. The speed of this bus is related to the FSB setting. As you up the FSB, you may need to lower the HT multiplier.

If your ram speed came up to at or above your stock setting, you may need to up the vdimm [ram voltage] in the bios as well. Just about all ram has a speed and voltage setting attached to the ram itself. If your ram can take more voltage, then I would set the value listed on the ram chip.

Overclocking is not an exact science. What works fine for one person may not work fine for you running a similar system. Overclocking requires you make an adjustment and test. Do not make multiple changes in the bios without testing for stability. If you made three changes, how do you know which one worked or did not work?
As an example of how much variation is involved, I have two systems running fx4350 and the exact same asus mb. Both overclock to 4.8gig prime95 stable however one system does not like the multi messed with at all and will only OC by upping the FSB. The other system will only tolerate a small increase in FSB however it overclocks just fine using the multiplier.

As an example you are overclocking your system and have reached the point where you get errors in your stability test. You up both the cpu voltage and the chipset voltage and now repeat the test. It passes the test. You do not know which adjustment [cpu or chipset] allowed your system to pass the stability test.

A few other reminders;

1 Do not update the bios on a machine that is overclocked. Return ALL settings to stock before attempting a bios update.

2 If you run into a problem, you can clear cmos and return bios settings to factory default. Some high end motherboards even have a clear switch for cmos located at the rear of the board. This is accessible from the back of the system without removing the side cover.

3 If you run into a problem, many boards will load defaults if you hold the insert key on the keyboard during post.


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## Jordster (May 14, 2008)

Also note that they must have significant cooling/air flow for a significant overclock.


And I think you made the message twice? I read the second half and it's exactly the same as the first half.


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## crjdriver (Jan 2, 2001)

You are right. I do not know how that one happened however I cut out the second part.

As for cooling, that is why you use temp monitoring software.


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## GTechWiz (Nov 10, 2009)

Upping your Multiplier without upping your voltage is like putting NOS on a yugo, BAD IDEA!


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## Adderad (Oct 27, 2009)

I'm never.. ever gonna overclock.
But clocking should be safe?


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## crjdriver (Jan 2, 2001)

Adderad said:


> I'm never.. ever gonna overclock.
> But clocking should be safe?


If it were "Safe" it would not void your warranty. I have said it many many times; There is NO safe overclocking.

Remember do not overclock with parts you cannot afford to replace.


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## Skivvywaver (Mar 18, 2001)

Good article Chuck. This is what this forum has been missing forever. I overclock and have done so for years. I've been fortunate and have never fried anything.



GTechWiz said:


> Upping your Multiplier without upping your voltage is like putting NOS on a yugo, BAD IDEA!


 Really? I have always been under the impression that lower volts = cooler machine. I am at 3.2 ghz on a Q6600 and I am below stock voltage. 

Maybe I should go crank her up to 1.45 volts huh? 1.28 just won't do.

You add voltage only when necessary. I can hit 3.6 ghz stable on my chip but I don't want it running 50C idle. At 1.45 vcore and 3.6 thats what temps I get.

Use common sense and watch your temps.


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## Adderad (Oct 27, 2009)

Still,i would never clock/overclock because im that kind of person that gets a baad stomachache if something bad MIGHT've happend to my precious machine.


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## chazshep (Feb 1, 2007)

Theyr'e other way of OC'ing aswell, PCI-e bus for instance. And the VERY advanced RAM settings which take a geological eon to get right.


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## lilb (Sep 16, 2009)

crjdriver said:


> A Basic Guide to Overclocking
> 
> Before we begin, there are some things you need to understand;
> 
> ...


Good guide i have overclocked many things over the years, a 7300gt ddr 2 was my best ever overclock from 350mhz core and 333mhz memory too 704mhz core 467mhz memory lasted 2 years. then stopped working. But before it died i got a 8800gt and then a GTS 250 (still using both) and overclocking both. Gts 250 from 750mhz core and 1120mhz memory too 806mhz core and 1282mhz memory and 8800gt is being used by my brother who runs it slightly overclocked. Intel core 2 duo e6750 from 2.66ghz too 3.12ghz stock volts. So yeah good guide btw very true though that there is no safe overclocking.


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## chazshep (Feb 1, 2007)

Oh and not ALL part warranties are voided. Some GPU's aren't. Also most RMA's still work when a part has been fryed.


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## Skivvywaver (Mar 18, 2001)

I got up this morning and was pleasantly surfing the net when wham...I shutdown hard. Reboot, shutdown reboot etc.

I figured PSU right off the bat so I disconnected everything I could do without. Endless reboot again. Still wasn't sure so I got the multi-meter out and tested as best I could. PSU checked out as good. This machine has 18 months on it so I figured shorting to ground wasn't likely...but it is what it is. I pulled the board, set her up on boxes and she booted, passed prime, all that stuff. 

I figured stand-off shorting so I switched out every standoff in the case and remounted the board. Endless reboots. Lather, rinse, repeat. Still the same. Outside of the case flawless, inside the case endless reboots.I figure one of my case leads has shorted, one of the LED's or switches. Who knows?

Ordered a new case but in the mean time...


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## Skivvywaver (Mar 18, 2001)

I actually thought, "Skivvy, you just bragged about never frying a part"...


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## doggy1 (Feb 26, 2005)

Basically don't overclock if you don't know what your doing? Ok, I got cha:up:


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