You just have to be careful of restrictiing yourself with your own components. For example, 2 gigs of ram is great until you realise your cpu may not be able to keep up to it anyways, and all it ends up doing is letting you run more processes than your pc can handle anyways. So you’ll be able to run 3 quake 4’s, 10 blenders and some firefox’s without using Swap space on your HDD, but if you can’t deal with them properly, it’s a waste.
For the majority of people, 1 gig of ram is more than sufficient, 2 gigs and you’re into the realm of gaming pc’s, where the extra ram counts. 3d is a little in the middle, some parts use high amounts of ram (Fluid baking etc.), but mostly it’s heavy on cpu processes. In any case, you won’t stop the usage of Page Files, without it you use much more memory than you need to, so you’ll suffer more anyways, at least under Windows currently. I have no idea about Linux.
So the key is to look for a nice middleground, where you have components that won’t restrict one another in the end.
Since Intel released the Core 2 Duo, AMD dropped prices on plenty of their single and dual core cpu’s, making them much better value for money. They’re fighting with their own Quad-core, but for your budget, I’d aim at an AMD dual-core processor. I’m still a little on the edge for 64-bit, as I don’t plan on going to Windows Vista, but there will likely be many optimized 64-bit programs shortly, so I wouldn’t shy from it if you find a good 64-bit cpu for a good deal. Dual-core 64-bit cpus may cost more, but it’s wiser to spend that money on a cpu than ram, as 2 gigs of ram is significantly more than 1 gig, and the performance is generally dependent on your cpu and gpu.
Honestly, unless your into high-end gaming, overclocking, or stressing your system, you won’t notice much of a difference between different speeds of ram, as long as they’re relatively good. For example, if you were looking at PC2700 and PC3200, you’d want to get the PC3200 for higher bandwidths, but you’re unlikely to need the more aggresive timings from the higher-end ram modules. Save the money and spend it on the cpu instead.
The graphics card is also an area where it depends on your preferences moreso than hard-and-straight lines for good and bad. If you’re into Gaming and High end 3d, a good card can make all the difference in the world. If you’re into general web-surfing and muddling around with 3d occasionally, it may be decidedly less important.
A couple of factors are key about Graphics cards, vram, type of vram, gpu and the slot.
vRam - Video ram, ranges currently in the midrange from 128 mb to 512 mb, higher and you get significantly more expensive. This is useful, but a 512 card is likely to be worth the amount you spend on it if the rest of the system isn’t up to snuff. great, you can load all of the textures from Quake 4 full settings into ram, but can your cpu handle the load, in addition to particle effects etc.? I’d probably aim for a 256 card here for a midrange pc.
Type of vRam - The same as normal Ram, DDR, DDR2, DDR3. DDR and DDR2 are more common on midrange cards, but DDR3 is becoming more and more used, so if you can get that with a good deal, it would be good. it determined the speeds the ram can handle, maximum bandwidth etc. Once more, one of those changes you may or may not notice, from DDR to DDR2, depending on how in tune you are with your pc.
Gpu - Graphics Processing Unit - It’s the cpu for the graphics processor, which helps offload most of the stress from your main cpu. You’re less likely to look at this category and decide a card based on it alone, but you may want to check for overclockability (Even 10 percent can give a nice boost with little price. You limit the life of your card a little, but with the current surging forward of technology, you’re likely to replace it long before it becomes an issue).
Slot - AGP or PCI-Express are currently the two main supported slots, with PCI-E quickly taking the market. If you buy a current motherboard, it’s likely to have PCI-E, which limits your choice of cards down a lot, which is nice for decisions. You can still find a great card for AGP 8x, so don’t be discouraged if an otherwise great motherboard only supports AGP 8x. It’s not the end of the world.
The motherboard is a very important part, but I know very little about them, so I can’t help much there. Just know that they will limit the choices you can make, simply due to what it supports. If you don’t have PCI-E in your motherboard, you can’t run a PCI-E card in your computer, (I suppose there may be ways, converters etc. but I have no idea about any if they exist).
Those 4 componants (CPU, Video Card and Motherboard and RAM) tend to be the choices most important, Hard drives aren’t much of an issue, getting decent speeds with high amounts of space is cheaper now than ever.
Hopefully this, along with the other posts can help you make a good decision on a good PC.
Contagion