Overclocking CPU questions

[KenM]

OK, I's upgrading my motherboard/ CPU. I'm going from an Athlon 2400 CPU 1.5 GB RAM to an Athlon 3800 CPU with 2 GB of faster RAM. I'm thinking of overclocking it to get more power out of it. Anyone know any good sites I can look at that explains how to overclock without going too far?

 

[drothgery]

CPU overclocking these days is pretty much useless. Most modern CPUs can't be overclocked by more than a few percent without exotic cooling (you may be able to get an extra 200-300 MHz... but remember that's not much on a 2-3GHz CPU). Throw in that your graphics card is going to be the limitting factor in games, and in normal business apps, even the slowest modern CPU is going to be more than fast enough. And if you're using CPU-intensive professional apps, then overclocking is probably not for you (if you're spending that much on software, you can afford to buy the best available hardware).

 

[Psionicist]

I sort of agree with drothgery, but not completely. There are always a few "golden chips" that overclock like crazy. For example, certein versions of Athlon64 3000+ overlock well over 50% with the standard air cooling. This if of course only good if you know what to buy, and buy a processor for the sake of overlocking it.

If you didn't, well, you can try, but it's generally not worth it.

 

[Rackhir]

Well this place looks potentially interesting.

http://www.overclockers.com/

However, the performance increase from going to the new Processor, MB and RAM is going to vastly outweigh the performance increase from OCing.

As mentioned you will need to carefully consider your cooling options if you really want to do any significant OCing. Water cooling is expensive and complicated, but definitely the way to go and has the benefit of being quiet.

Other likely bottlenecks are

1) Ram - Make sure you get dual channel ram. Preferably RAM sold as matched pairs.
2) System Bus - May require additional cooling
3) Graphics Card

A likely drawback to OC is increased noise necessitated by the extra cooling.

Also, depending on why you want to OC things, you might be better served by going with a dual core processor and/or an SLI graphics card config. For example, a dual core proc is great if you want to be doing multiple things at the same time.

 

[KenM]

I think I'm going to wait until I see what kind of increse I get first without overclocking before I do.

 

[ssampier]

I think overclocking is more for personal pride ("bragging rights") rather than actual performance.

Is this computer used for work or school at all? If so, if you're not careful, too much overclocking can cause excessive heat and permature wear which can cause system instability. If your computer is purely a gaming PC and you don't mind buy a new heatsink and various hardware components (CPU/motherboard/RAM/graphics card) when one is toasted, go right ahead. The gaming gods may smile on you.

As for performance, it depends on how careful ("foolish") you are. Less overclocking, it's not worth it; more overclocking and you can almost justify the trouble, but then it may lock-up or crash at the wrong time.

Yes, I have "tweaker" friends and no, my rig's standard.

 

[Psionicist]

Overclocking is not that worthless. Remember the CPU manufacturers themselves usually only create a few different processor versions in a family and then set the default clock speed to the highest stable possible. For example, a processor at 2 GHz and a processor at 2,4 Ghz are certainly created in the same factory and could be from the same batch too. You could say the slower processors in a family is just a flaky version of the fastest model, just that it couldn't handle the "intended" clock speed (the fastest one). Pretty much like hens and eggs: same hen, eggs of different quality.

My point is: If you buy a processor at 2 GHz and overlock it to 2,2 Ghz, there's no difference whatsoever between these two processors except the price, the identifying string and the default clock speed. So if you are lucky you could get the performance of the 2,2 GHz version for the price of the 2,0 Ghz version. That's what overlocking is about.

My friend bought an Opteron processor known to overlock well, and it runs at the exakt same clock speed as the Athlon 64 FX-57, a $1000-processor, with the default air cooling, and it can do Prime95 (a good stability test) for 48 hours. He was incredibly lucky though.

 

[KenM]

Well I have the upgrades. No need to OC. I'm running BF2 all on high with no problems.

 

[Rackhir]

My point is: If you buy a processor at 2 GHz and overlock it to 2,2 Ghz, there's no difference whatsoever between these two processors except the price, the identifying string and the default clock speed. So if you are lucky you could get the performance of the 2,2 GHz version for the price of the 2,0 Ghz version. That's what overlocking is about.

My friend bought an Opteron processor known to overlock well, and it runs at the exakt same clock speed as the Athlon 64 FX-57, a $1000-processor, with the default air cooling, and it can do Prime95 (a good stability test) for 48 hours. He was incredibly lucky though.

The chips are also guarenteed to run at that clockspeed within a certain thermal dissapation rating. In otherwords they'll do it while not outputing more than X watts of heat. While you might get a lower rated chip to run at that higher speed, it might well generate more heat than a stock cooling config can deal with.

The other point about OC was that a 10% increase in clock speed on the processor is likely to be negliable compared to the 60% increace in clock speed for the new processor along with probably a 100% increace in cache size and 50% increace in memory bandwidth.