Section 5.3. System Hardware

5.3. System Hardware

Not every performance problem can be fixed from within Windows. Here are some things you can do to your hardware to improve performance.

5.3.1. Managing IRQ Priority

Most components directly attached to your motherboard, including PCI slots, IDE controllers, serial ports, the keyboard port, and even your motherboard's CMOS, have individual IRQs assigned to them. An IRQ, or interrupt request line, is a numbered hardware line over which a device can interrupt the normal flow of data to the processor, allowing the device to function. Windows XP allows you to prioritize one or more IRQs (which translate to one or more hardware devices), potentially improving the performance of those devices:

1. Start by opening the System Information utility (msinfo32.exe) and navigating to System Summary\Hardware Resources\IRQs to view the IRQs in use on your system.

2. Next, open the Registry Editor (see Chapter 3) and navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\PriorityControl.

3. Create a new DWORD value in this key, and call it IRQ#Priority, where # is the IRQ of the device you wish to prioritize (e.g., IRQ13Priority for IRQ 13, which is your numeric processor).

4. Double-click the new value, and enter a number for its priority. Enter 1 for top priority, 2 for second, and so on. Make sure not to enter the same priority number for two entries, and keep it simple by experimenting with only one or two values at first. Some users have gotten good results prioritizing IRQ 8 (for the system CMOS) and the IRQ corresponding to the video card.

5. Close the Registry Editor and reboot your computer when you're done.

5.3.2. Overclock Your Processor

The processor is the highest-profile component (at least where marketing is concerned), as a fast processor often translates into a fast overall computer, especially with respect to games. But processors also become obsolete the fastest, and given how expensive they can be, it's often smart not to buy the fastest processor available.

Now, a processor's clock speed is just one of several factors upon which overall system speed is dependent. For example, jumping from a 1.5 GHz CPU to a 3 GHz unit will not double the speed of the computer. In fact, clock speed can be very misleading; a dual 800-Mhz system may outpace a 1 Ghz system, and a 1.4 GHz Pentium-III may outpace a 1.4 GHz Pentium-4. So keep this in mind when deciding how to spend your time and money on performance enhancements. That said, you may be able to squeeze a little more life out of your existing CPU at a fraction of the cost of a new one.

Overclocking is the process of instructing your processor to run at a higher clock speed (MHz) than its rated speed.^[24] For example, you may be able to overclock a 900 MHz chip to run at 950 MHz, or even faster. Supposedly, Intel and other chip makers have taken steps to prevent overclocking (theoretically prompting purchases of faster CPUs instead), but some motherboard manufacturers have found ways to do it anyway. Settings allowing you to overclock your CPU can be found in your BIOS setup (see Appendix B), assuming your motherboard supports it.

^[24] There's also the lesser-known practice of under-clocking a CPU. While this may seem silly, it's done to decrease power consumption and increase battery life on portable computers.

Now, over-overclocking a CPU (overclocking past the point where it's stable) can cause it to overheat and crash your PC frequently. The most important aspect of overclocking your system involves cooling; make sure you beef up your computer's internal cooling system if you plan on messing around with overclocking. (Obviously, your options will be limited here if you're using a laptop.)

Increase your CPU's speed in stages, if possible; don't start off with the fastest setting, or you may end up with a fried processor and lightly singed eyebrows.

If you feel that your system isn't adequately cooled, don't be afraid to add more fans. Some fans connect directly to special plugs on your motherboard, and are activated when internal thermometers detect too high of a temperature; these do a good job of cooling your system without generating excessive noise. Fans that connect to your power supply's drive cables run all the time, and will make more noise, but will do a better job of cooling your system. Peltier cooling units (also known as thermoelectric heat pumps) will do a great job without making any noise, but they are expensive and a little hard to find.