Insider Secrets for PC Buyers

Before you buy a car, you probably talk to your trusted mechanic about which models are really reliable. If you're planning to invest, it's great to have a friend working in the stock market who will help you find some winners. At PC World, we may not be able to help you choose an SUV or a blue-chip stock, but if there's one thing we do have the inside scoop on, it's computers.

In this guide we give you the latest information, as well as the top tips you need to make your next PC purchase perfect. We tell you which specs to seek out and which to ignore. We give you advice on how to save money without getting a chintzy PC. And we help you avoid problems with shopping, warranties, and returns.

Hardware

From processors and storage to graphics cards and LCD monitors, here's the inside information you need to know.

CPUs & RAM: Memory Matters

Hyperthreading Hype: Sales reps may pitch you on the multitasking virtues of hyperthreading, a technology found in the newest Pentium 4 chips. But PC World tests indicate that you won't see significant benefits from hyperthreading in many current applications. It may even slow down performance in some instances. Intel says, however, that you may see more of hyperthreading's advantages with future apps.

Count Your Cache: Get as much Level 2 cache on the processor as possible; the CPU uses it to store bits of frequently used data. A large cache helps you gain the fastest response from programs. AMD's top Athlon XP CPU and Intel's top Pentium 4 chips have 512KB. (For more information on AMD's newest chip, code-named Barton, see "AMD's Latest Is a Winner.")

MHz vs. Memory: Systems equipped with the top Intel and AMD processors produce similar performance scores on tests using common PC applications, but the type of memory makes a big difference. For top power from a Pentium 4 system, be sure to look for PC1066 RDRAM (Rambus memory). In systems with high-end AMD Athlon XP chips, choose 333-MHz DDR SDRAM. Fast memory is worth the money if you want every bit of speed you can get in everyday applications, or if your work involves demanding tasks such as image editing or video playback.

Coordinate Speed: Make sure that the motherboard in your system supports the main memory's top speed. For example, older motherboards may not support 333-MHz DDR SDRAM. This isn't an issue if you go with a top PC maker; but if you buy a budget or generic system, it may be.

Hard Drive: Focus on RPM and Cache

Speed Check: For top performance, pick a hard drive with a rotational speed of 7200 rpm, instead of one rated at 5400 rpm. Visit the drive maker's Web site if the PC vendor's list of components doesn't specify the speed.

Cache In: The hard drive's buffer size deserves scrutiny. Because the data you'll want next usually follows the data you just asked for, hard drives gather more data than requested and store the extra amount in a buffer. This prepares the data for transfer to RAM without the PC's having to read the disk if data in the buffer is indeed requested next. An 8MB buffer will improve performance over a standard 2MB buffer.

Ignore Both Serial ATA and ATA/133: If you're a typical user buying a power system that contains one hard drive, a Serial ATA hard drive is no big deal: It's just easier to fit in some PC cases because it uses smaller cables. Likewise, you won't perceive a difference between an ATA drive with a 133-MHz interface (ATA/133) and one with a 100-MHz interface (ATA/100), because a single hard drive isn't fast enough to take advantage of the extra bandwidth. For more on this topic, see "The Whole Drive Guide."

Double Up: For optimum hard-drive speed, consider a power system with RAID-configured hard drives. Using a technique called striping--a RAID "Level 0" hard drive setup that includes a controller card and two drives--can supercharge system performance on tasks like file copying and image editing. Vendors like Falcon Northwest and Alienware now pop these into gaming PCs.

Money Saver: Pick the second- or third-biggest hard drive. You'll land the sweetest deal by avoiding the top choice.