How to Overclock...?

I've heard about this technique of increasing system performance, though I do see the potential dangers of doing it, but I believe the benefits far outweigh the dangers. So, back on topic, I've read several guides on how to, but it still really confuses me. Help?

Last edited by KoolDrew on Sat Feb 25, 2006 8:25 pm; edited 1 time in total

I plan on writing an A64 guide once we finish up the site for this forum and everything. It will be a sort of step-by-step thing.

Anyway, what is it that you are confused about? To overclock you should first try to find the max for each component. You should find the max HTT, max for your CPU, and max for your RAM. When finding the max of each you need to take the others out of the equation. This is important because you are trying to find the max of that particular component. If you do not take the others out of the equation you may hit a wall that is actually caused by one of the other components.

When finding the max HTT you should set the HT link multi to something like 3x. This is important since the the hypertransport needs to be around 1000 or less. The HT link multi is multiplied by the HTT. So if the the HTT is 200MHz and the HT link multi is 3x that gives you 600. You also need to take CPU out of the equation. To do this you simply lower the CPU multiplier to something like 5x. CPU speed is determined by the multi multiplied by the HTT. The stock HTT is 200MHz and the multiplier for an Athlon 64 3000+ is 9x. 9x200=1800MHz=1.8GHz. You also need to get RAM out of the equation by setting a 1:2 divider. With a 200MHz HTT and a 1:2 divider the RAM would be running at 100MHz. In the BIOS it will likely say 100MHz rather then 1:2. As the HTT goes up so does the RAM speed. If the HTT is at 360 and the RAM is set to 100MHz it would be running at 180MHz. This is still below stock speeds so you know your RAM won't be the cause of you hitting a wall when overclocking the other components.

I like to start with finding the max HTT since everything else is derived from this value. After you have taken the other things out of the equation you should boot into Windows and increase the HTT using Clockgen (using the top slider in PLL Control) about 3MHz every 30 seconds while runing a \"in-place fft\" test using Sp2004. Keep doing this until SP2004 gives you an error or your computer reboots. Write down 5MHz under that value as your max HTT.

Then you move onto finding the max for your CPU. The RAM divider should still be 1:2 and your HT link multi should be 3x. So all you have to do is go into the BIOS and set the multiplier back to its default value (the highest one). For the 3000+ it would be 9x. Then boot back into Windows, start an in-place fft\" test in SP2004. Now do the same as before with ClockGen. Except this time you may want to give SP2004 a little more time. Increase the HTT 3MHz about every 60 seconds. Once SP2004 gives you an error you should increase the CPU's voltage and then see how high you can get. Just increase it in .05v increments until you get to 1.5. Higher then this is venturing out of safe territory and you risk killing your CPU. 1.55v-1.6v would probably be safe, but it is definitely better to play it safe. Also, if you start to realize that upping the voltage does not help you get farther then don't waste your time going further. Also, while doing all of this you should always be montioring your temps using the software that is supplied with yoru motherboard or with something like speedFan. The Temps should never exceed 55C at load. Then try running SP2004 for 30 minutes straight. If you get no errors then right that value down as your max. If you do, back down in 1MHz increments until you don't.

Now we are onto the RAM. This one is the most complicated and time consuming one. This is because you have to deal with timings too. So, since I don't feel like typing anymore I'll shorten it:

1. Download Memtest86+ and put it on a floppy or DVD/CD or something.
2. set CPU multi to 5x and RAM to 200MHz
3. Bump HTT up 3MHz
4. Run Memtest86+ test #5 (two passes)
5. If no errors, go to #3. If errors, either increase voltage or loosen timings.

Basically do this until it can run Memtest86+ for three hours (not just test #5). I can help you out a lot more once ou actually get your system and are starting to overclock.

Once you have found your max HTT, max CPU speed and max RAM speed, it is time to put it all together. This will be extremely helpful for that. Just put in the max's you found, set the multiplier to 9x fopr the 3000+ and just leave HT alone. This will give you the best options (from top to bottom). However, it will be likely that you will not have some of the memory dividers available. Most motherboards have 200, 166, 133 and 100. The DFI board has 100, 125, 133, 143, 150, 166, 183, and 200MHz. So just choose the best option that you can use with the options that you have.

After setting the settings in the BIOS it is time to test for stability. You already ran Memtest86+ for three hours at the max for your RAM so that is not needed. I would suggest running the following (in this order):

SuperPi (32M)
Windows Memtest (5000%)
SP2004 Blend (24 hours)
Loop game benchmark or 3DMark (6 hours)
Folding@Home ;)

Then you should know that your PC is pretty stable. It may even be a good choice to start Windows memtesting and then copy 3GB of files. Run Md5 hashes on themt o make sure the data is still intact.

I basically just wrote a guide.:lol:

Also, if you suck at math, use this:
http://i4memory.com/AMD64_tools/a64_mem_di...er%20helper.zip

It will help you to figure out what the RAM would be running at with a given HTT and divider.

Somewhat understood the guide, but thanks anyways. Now to order those parts.... :P

Last edited by KoolDrew on Sun Feb 26, 2006 2:56 pm; edited 1 time in total

The CPU speed is determined by the CPUs multiplier multiplied by the HTT. The 3000+'s max multiplier is 9x. The stock HTT speed is 200. So that gives you 1.8GHz (9x200=1800).

When you increase the HTT the CPU speed increases too. For example, you increase the HTT to 203MHz your CPU would be running at 1827MHz when using a 9x multiplier.

Last edited by Turkey on Sun Feb 26, 2006 3:28 pm; edited 1 time in total

The HT Link multiplier is similair to the CPU multiplier, just for the HT Link. The HT Link speed = HTT * the HT Link multiplier. As a general rule of thumb you do not want the final HT Link speed going over 1000. That is why I tell you to lower the multiplier.

Could you re-read my post above please?

The LDT ratio is another name for the HT Link multi. There may also be a LDT Voltage Control in the BIOS. This is how much voltage the HT Link will recieve. You shouldn't have to change this and it will be likely that your board doesn't even have the option.

When running a 1:1 (200MHZ) divider your RAM is running the same as your HTT. You will likely have to use a divider because your RAM will not be able to run 1:1 with your HTT. For example if you are running the HTT at 300 and your memory cannot run at that then you set a divider. When running a 5:6 (166MHz) divider the RAM would be running at 245MHz with a 300 HTT.

Last question, is the VCore the voltage for the CPU?

Yes. I wouldn't suggest going over 1.5v for that. Also, it is best to start at stock volts and then increase it in .05v increments once you hit a wall. Some people like to just start right off with 1.5v or higher, but I have seen some CPU's that are just weird and actually like less volts.

What are the stock volts, and is the 'wall' you are referring to errors or crashes?

Last edited by KoolDrew on Tue Feb 28, 2006 4:06 pm; edited 1 time in total

For the A64 3000+ Venice stock is 1.4v. Also, the 'wall' I am refering to would be the max overclock you can acheive. So you would try to find your max at 1.4v, upping the HTT in 3MHz increments, testing and continuing. Once you get an error you can up the voltage to 1.45v and test again.

Wait, so how many things can I overclock on the CPU? Frequency, HTT, and now FSB? Oy Vey....