Buying a new computer can be very exciting, but it may also be one of the more confusing things you ever do. Components change every month it seems, and misconceptions are abundant. For many users, the specs sheet may as well be written in Klingon. Understanding the differences between one hard drive and another is usually a skill reserved for the geekiest of us.

In this article, I hope to help you understand a little bit more about the common computer buying myths currently circulating. Big box stores love to take advantage of these misconceptions as they sell cheaper and less efficient wares to unassuming consumers. The sales clerks themselves may not be at fault here, as their employers usually go over the same five or six selling points that really don’t do much to influence the speed and/or efficiency of the machine.

Here are five of these myths, and how you can overcome being talked into a bad buy.

Graphics Cards with More Memory Are Better

If I were to tell you that a Gainward GeForce GTX 680 with 2 GB of RAM outperformed an AMD Radeon HD 7970 with 3 GB of GDDR5 RAM, would you believe that? The GeForce model number may be subconsciously compared to the higher one represented on the AMD Radeon. Further than that, the RAM difference is obvious, so why wouldn’t one outperform the other?

The Gainward GeForce GTX 680 operates at 1006 MHz. The AMD Radeon HD 7970 operates at a slightly lower 925 MHz, giving it an overall performance benchmark score of roughly 7/9 that of the GeForce.

This isn’t always the case, and other benchmark tests may disagree, but it is an example of how RAM is often used to sell a graphics card when it’s only a factor in the overall capabilities of the unit. More RAM is helpful, but it’s only a single factor in the card’s performance.

Processor Speed is Best Measured by Its GHz Rating

There was a time during the last decade when processor manufacturers sought ways to increase the MHz rating (clock speed) of their chips in an effort to get better performance without sacrificing the life of the unit. Cooling became a big deal, and still is among overclockers seeking ways to boost the power without risking overheating.

In more recent history, engineers have discovered ways to build processors more efficiently. A Core i5 processor running with a 3.1 GHz clock cycle may well outperform a Core i3 Processor running on 3.2 GHz. Even within the Core i5 family, there are differences in generations as one may have two cores and the other might be rocking four (virtual or otherwise). The best way to compare processors is to look online for performance benchmarks of the specific model.

For example, I’m running a Core i5-2400 CPU at 3.10 GHz. If I were to compare that to a first-generation Core i5 with the same clock speed, the difference in performance would be substantial.

Size is All That Matters on Hard Drives

Just like many things in life, size isn’t the most important factor to consider with hard drives. Yes, the capacity of a drive is crucial if you intend to use it to store large amounts of data, but the performance of the drive is also a big factor to consider. A hard drive running at 5400 RPM may not read and/or write data nearly as quickly as one spinning at 7200 RPM. Some drives made for gaming applications can exceed 10,000 RPM.

Even more impressive is the performance one might see from a solid-state drive (SSD). These drives require no moving parts and, as such, can pull data at remarkably fast speeds. This comes with a sacrifice in storage capacity, making it a hard sell for folks who have a lot of media to store. Still, you could always invest in a good external drive connecting by way of eSATA, USB 3.0, or Thunderbolt for storage purposes. A desktop computer may even have an additional space for a secondary internal drive.

When I buy a hard drive, I always take a look at the speed of the drive first. If it isn’t fast enough to keep up with the needs of a video editor, there’s little benefit to having an extreme amount of space.

Higher Price Means Better Performance

This is a very unfortunate misconception that you always get what you pay for in technology. While it’s true that going cheap will often bite you, there are plenty of examples out there of high-end machines being produced for less money than you might through more widely-known brands.

For example, an Alienware PC is typically considered to be the best of the best. You can, however, come pretty close in terms of performance at a fraction of the cost by buying a computer from another gaming system manufacturer. I’ve owned a system from CyberPower PC in the past and after almost four years, the machine is still being used to play the demanding games of today. I purchased the machine for about $900, which is about a third of what I would have paid for a comparable system from a bigger manufacturer.

You Need an Extended Warranty

Extended warranties sold by retailers are a sticky situation to jump into. On one hand, the warranty you spend an arm and a leg for might pay off should something go terribly wrong during the time it’s active. However, more often than not, you end up dropping a lot of cash for something that you never really need. Some stores even offer an extended warranty that matches that of the included warranty provided by the manufacturer.

In those cases, the benefits are simply that the store you purchased the extended warranty from would replace and/or repair your unit directly rather than referring you to the manufacturer. Is that really worth 20-30% of the product’s value? It’s a hard sell for me.

This is one instance where research certainly pays off. Find out what the manufacturer is willing to cover and compare that with the extended warranty provided by the retailer. You might be surprised just how often the two match each other, leaving no real benefit for the customer.

I mean, really, why would anyone want to spend four dollars on an accidental damage warranty for a CD?