New iMac 2012 Refresh Buying Guide: Should You Upgrade? Which Model and Options Should You Choose?

Apple's refreshed iMac line is out on Friday. Is it worth it to upgrade? And what options are available?

First off, do you even need a new computer? If your current workhorse is three years old or more, you should consider it.

These days, it's better to think of a computer as something you rent. Divide the initial cost by the amount of time you own it and you get an idea of how much you're paying.

Three years is a good run for a computer. You can stretch it to four years if you're willing to do a little maintenance, maybe even open it up to replace parts. If you're on a tight budget and you have some technical know-how, you can make it last five years.

If you've only got a laptop, you might want to add a desktop to your collection, too. The iMacs look good, take up only a little space, and can double as a television.

While the new 21.5-inch model starts as low as $1,299, it's usually best to upgrade a few options, so expect the final cost to be a few hundred dollars above the base price at least.

21.5" vs. 27"
The base stats for the different sizes are essentially the same. Both start with a 1 TB hard drive and 8GB of RAM. The 27-inch model has a slightly faster processor and graphics card, though those are upgradeable on all models. You can put the faster processor in the smaller model if you like, so choose a size based on how big you want the screen to be, as well as your budget.

Processor
Both models come with an Intel Core i5 processor. The difference in speed between i5 models is pretty negligible, so if you're going to pay for a faster processor, go all out and upgrade to the i7.

If you can't decide whether you need a faster processor, remember that you can't upgrade it after the fact. If you're planning on keeping your iMac for four or five years, I highly recommend spending a little more and getting the fastest processor you can afford.

Go to an Apple store after Friday and try out the new models. They should have at least one with an i7 on the floor. You can download the benchmark program Xbench onto a thumb drive and run it on different computers at the store to compare speed results.

Memory
Apple is notorious for overcharging on memory upgrades. The base 8 GB of RAM should be fine for most applications, and if you need more later, you can buy it much more cheaply and install it yourself. Don't buy it from Apple.

Hard Drive
A 1 TB hard drive is plenty for almost everyone, especially with cheap and ubiquitous cloud storage available. Apple offers a FusionDrive option that combines a 128 GB flash drive and a traditional hard drive to give the speed and capacity benefits of both.

But large-capacity flash drives are getting cheaper. You can buy your own and install it fairly easily if you want the speed of flash memory. No word yet on the pricing of the FusionDrive, but I'm guessing you won't save much with Apple's option. If you absolutely don't want to install your own hard drive but you still work with memory-intensive applications like video and image rendering, consider the FusionDrive.

Graphics Card
If you play a lot of video games, upgrade to the best graphics card you can. Unless you're quite good with computer hardware, I recommend having Apple do the upgrade. If you don't play video games, you should be fine with the base version.

Warranty
Apple products come with a paltry 90-day warranty. Buy at least the 1-year AppleCare plan. You can upgrade to the 3-year plan anytime within the first year, which can spread out the cost a bit. However, the plan starts counting down from the date of manufacture, which can be several months before you actually buy the computer, so make sure you check your warranty's expiration date.

Here are the specs and pricing for the two models before upgrades:

The baseline 21.5-inch model is priced at $1,299. It features a 2.7 GHz quad-core Intel Core i5 processor, 8 GB of 1600 MHz RAM, a 1 TB hard drive and an NVIDIA GeForce GT 640M graphics card.

The $1,499 model of the 21.5-inch iMac upgrades the processor to a 2.9 GHz i5 and the graphics to a GeForce GT 650M.

The 27-inch iMac starts at $1,799 for a 2.9 GHz quad-core Intel Core i5 processor, 8 GB of 1600 MHz RAM, a 1 TB hard drive and an NVIDIA GeForce GTX 660M graphic card.

The $1,999 model of the 27-inch iMac upgrades the processor to a 3.2 GHz i5 and the graphics to a GeForce GTX 675MX.