Overclock Your PC

Posted 12/31/2007 at 1:49pm | by Gordon Mah Ung and David Murphy

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Have the Right Hardware

Your CPU isn’t the only part that matters in your quest for more speed. Here are the other components to care about.

Motherboard

You get what you pay for and, generally, a cheap-ass motherboard will yield marginal overclocking results. The more expensive the motherboard, the more likely it is to have better components and better overclocking capabilities. That doesn’t mean all sub-$100 mobos are overclocking duds, but you’ll have to troll the forums and customer reviews on enthusiast sites to determine if a cheapo mobo can OC.

One additional tip: If you’re buying a motherboard for overclocking, you’ll likely have the best success with the latest “spin.” Mobo vendors update their boards with fixes and more recently built boards will usually overclock better.

Power Supply

We’ve long said that the PSU doesn’t get the attention it’s due, and that’s especially true when it comes to overclocking. The fact is, the need for clean, reliable power is of utmost importance if you’re pushing a CPU, RAM, and motherboard to the edge.

You don’t need a 1,200-watt PSU like this PC Power & Cooling Turbo-Cool, but you do need a quality, name-brand unit.

If you have a high-compression engine in your street racer, are you going to fill it with 85 octane fuel? A cheap power supply is the equivalent of questionable Kwik-E-Mart gasoline. For overclocking, you don’t need a 1,200-watt PSU, but you do need a name-brand unit. Generally, it’s safer to have a PSU that delivers a bit more power than you need. While it may not be the most power-efficient scenario, a 750-watt PSU running at 450 watts will probably live longer than a 500-watt PSU running at 450 watts.

Cooling

Excessive heat can cause system instability, so it’s essential to keep your overclocked CPU cool. To achieve extremely high overclocks, some hobbyists bathe their CPUs in liquid nitrogen. Others use phase-change units (essentially tiny freezers) to push 3GHz chips past the 5GHz mark. The point is, you can’t expect to push your 1.86GHz proc to a reliable 4GHz using a $12 heatsink. Know your overclocking goals and then choose your cooling accordingly. Air cooling is the most modest solution, followed by water cooling, peltier/liquid combinations, phase change, and exotic liquids, such as liquid nitrogen. Also remember that the extra heat produced by overclocking will warm up the rest of your machine, so you may have to upgrade your case’s cooling or the case itself if you experience overheating issues. For our CPU cooling recommendations, see page 34.

Memory

In the old days the front-side bus’s speed was tied to the speed of the system RAM, so you had to overclock both. That’s no longer the case, but some folks still prefer to give their RAM some extra juice. This is the purpose of pricey, high-performance RAM. It’s been certified by the RAM manufacturer to operate at a given “overclocked” speed. We say overclocked because RAM speeds and timings are actually spec’d by an organization called JEDEC. The top standard speed of DDR2 today is 800MHz. Overclockable DDR2 RAM generally runs in the 1,066MHz range, with some pricier modules pushing 1,250MHz. While it’s not necessary to overclock your RAM to overclock your CPU, there are some instances when you will get improved performance if the FSB and RAM run at similar speeds that are closely synced. Some applications will also favor the increased bandwidth of overclocked RAM. Your research will help you determine if this applies to your parts.

Overclocking an OEM Machine

So, you’re ready to crack open your business-class Dell, HP, or Gateway and give it some gusto, eh? Fugetabout it. The overwhelming majority of OEM machines and notebook PCs prevent overclocking to reduce complaints from the chumps who OC recklessly and ruin their machines. Even motherboard brands known for overclocking may be neutered in an OEM machine. Got it? OK, now we’re going to contradict ourselves. Some OEM boxes do overclock. Dell’s XPS and Hewlett-Packard’s Blackbird PCs are designed to overclock. Still, for the most part, overclocking and OEM machines don’t mix.

Next: Overclocking Intel!
Or, skip to Overclocking AMD!