Can't get back to 4.8GHz?

[Sleetz]

I was just curious as to why I was once able to overclock to 4815MHz -- 240 Bus Frequency -- x 20 multiplier -- 1.42v. Then not.

I had it steady for 8+ hours so I decided to try to overclock my graphics card which then I finally got a shutdown. After that I could not get passed 4750, although they are a relatively close overclock I was just wondering if I permanently damaged the chip?

 

[zjuventus14]

It is possible. What CPU do you have? The generally accepted maximum voltage you should use, unless you are using some sort of ridiculous cooling system, is 1.4V. Also, did you change the base clock or the bus frequency manually? If you did, there is a good chance you may have damaged the chip.

 

[Sleetz]

It is possible. What CPU do you have? The generally accepted maximum voltage you should use, unless you are using some sort of ridiculous cooling system, is 1.4V. Also, did you change the base clock or the bus frequency manually? If you did, there is a good chance you may have damaged the chip.

My specs are in my signature but (AMD FX-8350 4.7GHz) and I have seen people at 5.1GHz at 1.58 voltages. 1.4 is not too irregular. I did change my bus speed manually but it was running fun until I overclocked my graphics card.

 

[zjuventus14]

My bad, I was under the impression you had an Intel CPU. However, it is possible that you have a bad binned CPU(does not overclock as well as others), and it could not handle those voltages. I, for example, have an intel 5820K. Almost all of that CPU model can handle a 4.2 Ghz overclock at 1.3 volts, while I can only reach 3.8 Ghz and can only go up to 1.2 volts.

 

[Sleetz]

My bad, I was under the impression you had an Intel CPU. However, it is possible that you have a bad binned CPU(does not overclock as well as others), and it could not handle those voltages. I, for example, have an intel 5820K. Almost all of that CPU model can handle a 4.2 Ghz overclock at 1.3 volts, while I can only reach 3.8 Ghz and can only go up to 1.2 volts.

What kind of power supply do you have?

 

[zjuventus14]

I have a 750 Watt EVGA 80+ Gold Certified Fully Modular Power Supply

 

[Sleetz]

I have a 750 Watt EVGA 80+ Gold Certified Fully Modular Power Supply

Strange you should be able to get a higher clock. I have a Noctua air cooler coming in tomorrow I am going to try for 4.8 with that, if no luck I will have to settle with 4.7.

 

[photonboy]

Hey,

First of all, not every CPU of the same model will overclock the same due to slight manufacturing differences. This is called the "silicon lottery".

Second, when you get a CPU to a specific frequency but then can't get it stable again there are explanations. If you are just barely stable then small changes to the CPU, power supply, motherboard, or ambient temperature are possible reasons why you suddenly can't achieve that overclock.

*My advice is drop 200MHz below where you crash at minimum. I'd personally go with 4.5GHz and the lowest voltage that seems stable then a small amount more.

Summary:
You'll likely NEVER KNOW why you can't quite achieve the max overclock you did before but provided you still get a good overclock I wouldn't worry too much about it.

update:
Do note that stress testing the CPU like Prime95 creates much more heat than gaming or even video editing. If crashing is HEAT related you might be stable at a frequency that would cause Prime95 to crash.

On the other hand it could be a voltage issue which has a few parts involved. Either way, I prefer to aim for the worst case (Prime95) and if that's stable there should be no worries.

update:
Don't forget to run MEMTEST as well to test DDR3 memory... and also don't forget that overclocking memory can also cause crashing.