Push Your RAM to Its Limit
When it comes to overclocking, the processor and graphics card typically end up hogging the spotlight. Cooling manufacturers have crafted hundreds of different heat sinks designed to give obsessive PC enthusiasts an edge in pushing components well past their rated specs. Even case designers have jumped into the act, with special cooling ducts and other contraptions aimed at keeping the CPU and GPU chilly. That leaves RAM as the redheaded stepchild in the hardware family, but because we love all our components equally (and because we're just a little nuts), we're going to show you how to make those modules scream.
Enter the BIOS
You may be tempted to use a software-based overclocking utility to tinker with your system, but for hard-core tweakers the BIOS offers far greater control over a wider variety of settings. To get into your machine's BIOS, press the Delete key during the first seconds of boot-up. Depending on your motherboard or system vendor, you may be prompted to press a different key, such as F2 or Esc. Consult your manual if necessary, but you'll need to deduct 100 geek-cred points from your overall score.
Not all motherboard makers use the same type of BIOS, and even different models from the same vendor can vary. But one thing almost all have in common is that the overclocking settings, if offered, are typically clumped together under one menu. Look for labels such as MB Intelligent Tweaker (Gigabyte), Extreme Tweaker (Asus), Cell Menu (MSI), or other similar terms.
As you increase your RAM's frequency, your CPU will ramp up in speed too. This can cause you to run into an overclocking wall prematurely, even though your RAM has room to spare. To prevent that from happening, locate the CPU Ratio Setting in your BIOS and drop your CPU's multiplier down at least two whole numbers, preferably as far as your motherboard allows. Using an Intel Core 2 Duo E8400, dropping the multiplier down from x9 to x6 decreases the CPU's clock speed from 3.0 GHz to 2.0 GHz, giving you plenty of headroom to play with as your push your RAM to absurd heights.
Next you'll want to relax your memory timing. If the latency settings are grayed out, change the DRAM Timing Control (or other similarly labeled item) from Auto to Manual. For DDR2, loosen the CAS Latency Time (TCL), RAS to CAS Delay (TRCD), RAS Precharge (TRP), Precharge delay (TRAS), and Command Rate (CMD) to 6/6/6/18/2T respectively, and for DDR3 set the same settings to 10/10/10/28/2T. Refer to your motherboard manual if you can't find these settings in your BIOS, and deduct another 100 points from your geek-cred score.
Cool It and Juice It!
Once you've eliminated bottlenecks and pushed your RAM's frequency as high as it can go, the real craziness begins. Increasing your RAM's voltage can give it more headroom--give it too much, however, and your modules will give up the ghost in return. Consider 2.4V and 2.2V the respective red zones for DDR2 and DDR3. To keep from involving the fire department, invest in an active-cooling product such as Corsair's Memory Airflow Fan; or if you really want to push the envelope, pick up a water block for your RAM and integrate it into your water-cooling loop (see page 5).
Once you've taken your RAM to the bleeding edge and survived, slap your PC's case back together and crank it up. If nothing melts or starts to smoke, you're solid.