Overclocking for n00bs

Hiya,

I'm pretty literate about most things computer (admittedly more software than hardware), but people talk about overclocking here and although I kinda grasp the basics like multipliers and stuff, a huge amount goes straight over my head especially when it comes to voltages.

So, I was thinking ... maybe this thread could serve as a link to all the decent "How to start overclocking" sites that people know, or even for people to write their own guides?

Hope someone's got some good tips so I can start to learn more about this subject.

Thanks :D

First you must have some basics on how a motherboard works . It has a clock generator that gives a certain frequency . This value is multiplied by certain numbers , and gives the FSB frequency , RAM bus frequency , PCI frequency , AGP frequency ... Notice that the FSB is not the same thing as RAM bus frequency , this is a common mistake . Also , the RAM and FSB frequencies are different from the actual speed , wich is twice as fast , because they are working at double data rate (DDR) . Example : 266FSB runs at 133mhz . In conclusion , all the speeds on the mobo depend on it's clock generator .

Now , the CPU has 3 important characteristics : it's FSB , multiplier and core voltage . The actual speed of the CPU is FSB freq times multiplier . Example : XP1600+ has a 10.5 multiplier and 133 bus , so it runs at 133 x 10.5 = 1400mhz .

For a good overclock , you will need a good motherboard , wich has settings for fsb increase mhz by mhz , CPU multiplier , CPU core voltage , RAM voltage and RAM latencies .

Most of the AMD chips come multiplier-locked , so you have to unlock them . There are many guides on the unlocking stuff out there , just search one for your particular type of CPU .

First , you must make sure that the CPU is set at the same bus as the RAM , otherwise one of the 2 will not use the other's extra bandwidth , and you don't want that . For example , if you have PC2700 memory and a 166mhz RAM capable motherboard (like the ones with the KT333 chipset) , you should set the CPU also to 166 mhz FSB , and lowering the multiplier below the default value , until the CPU frequency is around 20% under the default one . This is very important .

Now you start increasing the FSB (really you are increasing the mobo's clock , wich takes all the frequencies -AGP,PCI,RAM- higher) , keeping the same low multiplier . The purpose is to get the best FSB stable , no matter what speed the CPU is .To gain stability at high speeds , you must add more voltage to the CPU and to the RAM , sometimes even to the AGP slot , but usually you don't need that . This is a very tricky thing , because voltage brings stability , but also heat , and heat is bad for stability . With a good cooling setup you can take out all the extra heat , try to keep you CPU under 50 C if you can , and never let it go over 60C .

For good performance you can use the best timings on the memory :
CAS latency 2
4-way bank interleave
1T command
RAS & RAS to CAS delay & all the other stuff to minimal latency .
Using these settings help your performance at a certain speed , but they can bring instability , so it's a matter of trial and error . Without them , you'll be able to hit higher frequencies on the RAM , but the real performance may be lower (depends on the type of RAM).

When you hit the highest FSB stable , you can start tweaking on the CPU multiplier . Increase it in 0.5 increments , until you have the highest possible speed , stable . The CPU core voltage increase will help you again .

Remember , always an eye on the temps , 60C is the maximum you should go . The lower the temperature , the more stable at high speeds the CPU is .

Blatently plagiarised but covers the basics

Still seems a bit complicated. I think I understand it, but to be honest I was looking for (intially at least) a step-by-step guide to overlocking from scratch, telling me what tools I need (physical and software) and what effect each step I perform has physically on the system.

Saying that, what you've written will undoubtedly be of benefit once I understand the basics a little better :D

Overclocking from scratch -
Hardwarewise you don't need anything new.
Softwarewise the two most useful programs are Prime95(This will test your CPU/Memory stability) and Memtest 86(memory stability), it is also worth getting motherboard monitor 5 to keep an eye on your temps
Go into the Bios and lower the multiplier a few notches(This is described above) and aim for your maximum FSB(increasing in steps of 5-10) and then running prime95 after each reboot. If you get errors then the cpu is unstable at the new speed. A way to increase stability is to give the cpu more volts so once you hit instability, up the voltage till you are stable again. Once you can go no further with the FSB then start upping the multiplier until you run into heat problems.

Further to this most Nforce2 motherboards can unlock the multiplier on most athlons and durons upto week 39 IIRC

Most via boards will as well. Anything from the Pally until week 39 is unlocked

Seeing as (in your other posts) your going to get a A64 939 maybe you should ask specifically about over clocking that... Then it will make more sense when you come to doing it with your stuff.

Most of it turned up today, so yeah; guess it makes sense to post what I'm going to be maybe overclocking.

Athlon 64 3500+ (Socket 939)
Asus A8V-Deluxe Mobo
Geil Value 1Gb PC3200 Dual-Channel DDR Kit (2x 512Mb) (5ns Cas 2.5 8-4-4)
200Gb Maxtor DiamondMax Plus9 SATA UDMA150 8Mb Cache
Gigabyte GV-R80X256V Radeon X800XT VIVO (AGP)

I realise the ram isn't the best, but I wanted to spend more on the processor. I'm not definitely wanting to overclock this (and indeed I shan't immediately), but I'm also interested in how one goes about it in addition to contemplating doing it to my setup.

You may have run into a little trouble there.
The way i understand it, Athlon 64 cpus do not allow higher multipliers.
If this is the case then you will probably be limited by how far you can push that Geil RAM.

Quote:

---

Originally Posted by GreenPiggy

You may have run into a little trouble there.
The way i understand it, Athlon 64 cpus do not allow higher multipliers.
If this is the case then you will probably be limited by how far you can push that Geil RAM.

---

I also though that Athlon 64s generally don't overclock very well?

a64 clock fairly well, they are all unlocked due to the cool'n'quiet technology, havent done mine yet but will do soon enough