Buying a Desktop PC - What to look at?

The “incredible graphics” and “giant memory” you see on inserts or advertisements mean something after you purchased the item. Of course a meaning negative to your wallet. Only until you know what to look at and ask the right questions you can save yourself from wasteful spending.

The golden rule that applies to shopping also applies to electronics: Determine your needs first. If you want a desktop computer for your office productivity tasks, surfing the Internet, listening to music, oe even watching movies, you do not need the fastest computer around. On the other hand, if you are a serious gamer or a technically-oriented person who loves overclocking, you will not benefit much from an office-type computer.

 The sellers love to be proud of the computer’s processor (Central Processing Unit – CPU) speed. However, for your daily office and multimedia tasks (I will call them “office-type computers”), you only utilize a fraction of this speed and the remaining part just has a marginal effect on performance. So, you will not need the latest, fastest, greatest CPU, but an entry-level one. If you are into 3D design or do some other intense number crunching, then you have to consider the number of cores on the processor, as well as the speed. A low-speed CPU speed with many cores will not deliver the same performance as a faster but a dual core processor in most cases. If you are working with high-performance applications, have several windows open and many tasks running in the background, then it is better to think about a quad-core processor. If not, a dual-core will do fine.

 RAM is one of the real issues to know. A 32-bit operating system can not work with more than 4 GB of RAM, because it can address only 2³² of space, which comes near to 4 GB. There will be deductions from this amount, because of some addressing issues, like:

1. On board graphics adapters will “steal” some space from the RAM. This is what I noted above: if you use 4 GB with an on-board graphics card, it will eat up it’s memory from your overall RAM. If your on board graphics can use 1 Gigabyte (say 1024 Megabytes) of memory, and the onboard graphics have 128 Megabytes of their own memory, the remaining 1024 – 128 = 886 Megabytes will be stolen from the main memory. So, if you have 4 Gigabytes (4092 Megabytes) of RAM, 4092 – 872 = 3224 Megabytes will be available.
2. Today’s modern graphics cards require address space for their on board memory. Meaning that, if you have a graphics card with 512 Megabyte memory, then in your operating system you will see 4092 – 512 = 3584, or about 3.6 Gigabytes in your operating system. So, 4 GB is not what you will get. Three and change is still better than two though.

Normal office applications, web surfing, and watching movies can be done without problem on 2 GB of ram. Gaming and multitasking benefit from 4GB, even if it isn't all in usable. Computers with 64-bit operating systems can see all 4 GB of memory and more.

On the next page: Grapics Card, Motherboard, and Sound Card Selection