Overclocking 101 – What, Why and How

Overclocking 101 - What, Why and How

What IS Overclocking?

Layman explanation : To set your components to run at faster than default speed. Say a 3Ghz processor running at 3.1Ghz. Even if it’s 3Ghz to 3.001Ghz – it’s an OVERCLOCK!

Why Overclock?

Layman explanation : To get more value out of it. I remember my best overclocking processor, the AMD Athlon XP 1700+. The default speed was 1467mhz but I pushed it to about 2.3Ghz. That’s a 56% overclock, making my sub RM 200 processor perform just as good as a processor that costs more than RM 1.2k.

Does it reduce lifespan of the item? Yes of course, as long as you’re using a component, the lifespan in the reduction process. Overclock would theoretically reduce it at a faster rate but it’s not something I’d worry about. If a processor lasts 10 years, I don’t mind reducing it to 3 years but I get to enjoy the superb gain in processing power and value for money.

Check out my latest article on bottleneck and how overclocking can help

How to Overclock?

Here’s a short video on how I overclocked my X3 425.

Bear in mind that this video just shows you what to change. The journey of overclocking can be quite a long and tedious one, during my college days (late 90s) I spent many hours just to overclock because I was picky on finding out what’s the true maximum overclock I can achieve and maximizing it. I no longer do that, my overclocking these days are more simple. Usually about 30 minutes or so.

Overclocking involves a lot of patience, and dealing with a lot of failed boots, configuration resets and re-configuration.

Basic Understanding of Speed

In this article, I’ll cover only processor overclocking. I’ll talk more about graphic card and memory overclocking later.

A processors clock speed (3ghz) is derived from having a multiplier multiplying frequency. In the video above, you’ll notice that it’s called FSB Frequency, FSB for Front Side BUS. We’ll just call it BUS for the sake of simplicity.

If you must know, new generation of Intel processors use QPI while AMD processors use HTT but you know what – they work the same! 😀

What do you need?

You just need to know how to ENTER BIOS and how to CLEAR CMOS (Refer to the manual, it’s usually done by swapping the jumper location and back). That’s when you screw up the overclocking by saving a setting that’s beyond what your system can handle. We do that all the time.

What? Your friend told you that you need to buy an expensive cooler before you start overclocking? LOL. Ignore them, they’re probably some misguided overclocking newbies to begin with. Stock coolers are fine for overclocking, it’s just that their thermal dissipation capability limits how far you can push your processor but look at it this way, my X3 425 works at 3.6ghz with stock cooler. 😛 You just need to know what you’re doing.

What should you do?

Have a look at the video again. The idea is there.

Step 1 – Pump the BUS speed. You could go with 5 to 10 Mhz increments, this will get you comfortable with overclocking. Don’t worry, you’re not dealing with a bomb. I’ve never injured myself nor any other component over the past 15 years or so from my overclocking mistakes.

If you’re comfortable, you could just go for bigger increments. For me, I usually estimate the % of overclock I expect to get and set the FSB required straightaway. Or if not, I’ll just check out the forums or review and see how far people have reached using the same or similar processor.

I assume that you should know by now that Step 1 is meant to be repeated until you face abnormal operation. 🙂 Ok so maybe you don’t but now you know.

Abnormal operation could be that
a) the computer is not showing the POST screen at all (POST – Power On Self Test, you know, the black screen where it shows the numbers, the part before entering BIOS.
b) you pass the POST screen but the OS is just acting up. The symptoms vary, some would just hang or not even show the OS loading screen but others may allow you actually reach the desktop and to only hang or crash when you’re running some application.

Always take note of the last frequency you tried, once failure is reached, we’ll go to step 2 and we’ll need that information.

Step 2 – Failure doesn’t necessarily mean you’ve hit processor limitation. Quite often this could be overcome by pumping additional voltage.

If the system refuses to work at all, just CLEAR CMOS and proceed with setting the frequency to the last one you used, and up the processor voltage a little, say 0.01 or 0.02. The name varies from BIOS to BIOS, some call it “vcore”, others call it “processor voltage”, the one I’m using calls it “CPU voltage”. You can find out the processor voltage from the details on the box, and also the product website. Software like CPU-Z are useful to monitor your processor as well.

After that, save and reboot. Resume “Step 1”. Take care in voltage increment, I wouldn’t go too far in voltage pumping. Personally I prefer to stay within 0.10 range. More voltage pumped also mean more heat generated.

Another possible cause of failure is the memory frequency. Refer to the video, at about 0:32. Notice how I change the FSB/DRAM ratio. The resulting figure should be within your RAM’s operational speed. We can actually have it beyond the RAM’s operational speed but that would involve the overclocking of RAM. (Refer to the next section)

Step 3 – Once you feel happy with the overclock, time to feel unhappy again. Why? You still need to test the stability. You could just use softwares like the one I used for the Intel Pentium G6950 Processor Review for stability tests. Throw in some games along and if it goes all well, the system is good to use.

Does that mean it’s 100% stable? No, unfortunately not. It could be just 80% or even 95%. You could run software like Orthos or OCCT if you want to be picky and run it 24/7 for 7 days straight to see if any error pops up. I used to do that but nowadays I couldn’t be bothered, as long as my games and usual application run fine, it’s all good. 🙂

Overclocking of RAM / Graphic Card

Overclocking of these 2 works the same. RAM overclocking is handled in BIOS. RAM speed is tied to FSB and you’ll have to adjust the processor FSB to get the RAM speed beyond default and see how far it goes before having to pump the voltage for the RAM. RAM can be tested with Memtest86+.

As for graphic cards, graphic card manufacturers often bundle their software to allow overclocking, for example Galaxy has their XtremeTunerHD which is a very nice overclocking software. Not sure if it works for other brands. MSI has a really funky looking overclocking software too.

Hmrmrmrmr…….. Anyway the logic works the same, just push the speed, fail. reboot / reset. blablablabla.


I had intended this to be a short article. Looks like it’s not easy to summarize OVERCLOCKING. I think there’s probably a bundle of typos and weird grammatical blunders above, couldn’t be bothered to check.

Anyway, I’ve got nothing to summarize, which I donno why I put the title as SUMMARY to begin with – got some free time to spare? Go try overclocking. 😉 On a side note, I was suppose to write about overclocking in 2007 I think. Very delayed article completed in less than 2 hours. LOL. Damn. Have fun overclocking la, any question can ask here. NO guarantee I can answer everything. 😀

No article for a long time? That’s cos I got some dates mixed up and thought I had something to write about during the weekend. Those of you interested in Overclocking Workshop could also check out the one organized by Gigabyte, click here.

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  1. Is there a chance for data corruption with overclocking? I’d hate to reformat because of failed overcloking.

  2. AMD always have stability and heat issues compared to Intel?

  3. Author

    @frags : it is possible but in my many years, I rarely even face such problem. Any crash is pretty much like the usual Windows crash, if it still happens to you. Windows Vista and 7 have been stable.

    @fariqto : Nope. AMD has been great for many years already.

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