Gold certifiied PSUs are expensive, and the difference between Gold and Bronze is about 5% efficiency. For that, you're going to pay at least double the price. It's more important to get a reliable model of power supply from a reputable integrator (e.g. Corsair HX or TX models) than an overpriced certification that the power supply probably doesn't even meet in service.

Give me regulation over efficiency any day.

No, Core 2 Duo has been obsolete for enough years that there is no longer a decent selection of either CPUs or compatible motherboards.

The fact that many people still have working Core 2 Duo systems does not mean it is a suitable choice for a new system.

Athlon II (Socket AM3) for the most cost-constrained systems.
Core i3 (either Nehalem or Sandy Bridge).
Phenom II (Socket AM3).
Core i5 (either Nehalem or Sandy Bridge) for high-end gaming systems.
Core i7 (either Nehalem or Sandy Bridge) for professional systems.

Bulldozer should be interesting here the ES leak (if real) shows a 3.4GHz chip scoring higher than a i7 2600k in benchmarks which should shake this up a little and lower prices across the board

Personally I'd get a Phenom II rather than an i5. It seems to be as good as it in practical terms, but is cheaper. 4GB of DDR3 RAM is pretty cheap now. Windows 7 is actually very good and will allow you to use DirectXs beyond 9, which your graphics card will be able to take advantage of. And yes, dual core CPUs aren't really something you should buy now. They've reached their peak, they're just going to get cheaper now, not faster. If you build it around a dual core CPU, your other hardware will be based on that socket set and will therefore be instantly out-dated and impossible to upgrade without buying a whole PC from scratch again.

I'm not sure how prices in your country and mine vary, but I got the HD 5850, Phenom II 3.2GHz (easily overclockable to 3.6GHz) Black Edition, 4 GB of Corsair DDR3 RAM and some motherboard with a built in graphics card that was far better than my last PC's card. Plus the power supply unit, of course. It all came to about £350 including next day delivery.

That article just goes to show the likelihood that anybody who tries to build a "future proof" computer will be shown up for a fool.

The writer led off his decisions with the advantages of going with the most expensive possible CPU-motherboard-RAM setup (Core i7, LGA 1366, 3-way interleaved RAM), without considering any alternatives.

LGA 1366 and 3-way RAM are now officially obsolete, with no upgrade path other than buying a new CPU, new motherboard, and a fourth stick of RAM in the hope that it won't be mismatched with the three he already has.

Future proofing, pfui.

You can use XP, but why would you? XP 64 is unusable, why have a brand new quad core 64 bit w/o a 64 bit OS?

If you have the cash, 2xquad core Xeons, imo. Throw around 16GB of RAM in that bad boy.
You're fairly safe buying a nice full tower case, you're right about all the other components, though. Figure out your budget and how long you want the rig to last (maybe save 200 bucks for a midpoint vid card upgrade). Then go and price out the best bang for your buck and go with that, it works for most folks.

There have already been a few games that are Vista/7 only. Halo2, Just Cause 2 and Shattered Horizon off the top of my head. Halo 2 can be cracked to run on XP though.

Non XP games have been around for awhile Just cause 2 is one for example

One interesting question is: IF I buy capable PC now, will it be fast enough to run HL2 Episode 3 when it is released?
How fast hardware requirements go up nowadays?

About Windows 7... do new peripherals and other components, like processors, support XP? When XP was released there was no multicore processors nor PCI-express buses etc... etc...

Most components still have XP drivers. XP is still very widely used, especially in business, where there is not much use for most Vista/W7 features. The cutoff seems to be at XP SP2, sometimes you'll see a driver that requires SP3.

The ability to create faster hardware runs ahead of the ability to create software that makes full use of it. DirectX 11 is a good example. So anything that is state of the art now should have a good two to three years life span before software that requires something newer starts appearing.

All you can do is two to three years, though. Future proofing beyond two to three years out is a losing game. The future comes at you much faster than that.

HL Ep. 3, how long did you want this computer to last? Until the heat death of the universe?

Haha, I kid, it will only have to last until around the time our sun burns the Earth to a crisp (500 million years or so).

no you dont.u could you xp or vista or 7 or even linux.how well it works depends on components and the drivers available.get as much ram and best cpu you can afford.like one of the others have said 2 to 3 years is about as futureproof as u can get.by that time if u upgrade again it can be a bitch to find quality new compatible components..mite as well complete new system at that point

i5 750: is it cheap? If prices are like in the US, the total system cost for a decent SB will only be slightly more. The main advantage to Nehalem, right now, is cheaper overclocking, but a 750 aught to be awfully close to a 2500(K) in price. If you do not plan to overclock, the 2500 and 2500K are interchangeable, as are motherboard chipsets for socket 1155. IMO, going AMD would be a better way to shave costs v. Sandy Bridge, than going with Nehalem, should that be the reason for the i5-750.

HD 5850 1GB: the prices are right. It is hard to go wrong with a GTX 460 1GB, HD 5850, or HD 5870. The HD 6850 is a decent bit more power efficient, but has no other real advantages over the 5850. IMO, get an MSI Hawk, or a Sapphire VaporX, if you can, for the sweet coolers and otherwise good quality. Price may rule those options out, however.

Mainboard: this is CPU dependent. Changing to S1155 would change available options, as would going with AM3.
* USB 3 could be handy to have on the board, particularly if it is a microATX.
* SATA 6Gbps, hyped on every motherboard's feature set, is patently useless for 99% of users. Of the leftover 1%, most of them find it useful as an e-peen, paired with a fast SSD, and don't take any real advantage of it.
* If you get Windows 7, before the install, go turn AHCI on for all your SATA ports. Windows quietly enables several useful features, if you install the OS with AHCI already turned on, notably NCQ, which makes quite a difference in Win7, and hot-swap, which you may very well never use. It can be enabled later, but it is easier to have it from the beginning.

2GB RAM: 4GB, as 2x2GB, minimum. RAM is way too cheap not to, and using more than 2GB is very easy to do. Make it a point to get 1.5V rated RAM, too. Never, ever, ever, EVER skimp on the amount of RAM, if you can afford it. Note that if you stick with a 32-bit OS, you will not be able to use more than 2-3GB, as any devices that use DMA start taking up address space, and your video card's RAM tends to be included in that.

OS: you may use XP, but you will lose out on DX10 and up, will be limited by RAM, and XP support ends in 2014, which could be within the useful life of the PC. Typically, you will see software you want that does not support it within a couple years of support ending. XP got treated special, because Vista was a turd, but as 2014 approaches, don't be surprised if it gets to be problematic. I would get Windows 7 64-bit, and keep a 32-bit XP box for games that flat will not run in 64-bit.

Not mentioned: an affordable PSU for such a system, if not overclocking at all, or not much, would be pretty much any of Corsair, Antec, or Seasonic's 400W to 500W units. Go with 500W, or a bit more, if overclocking. Don't get too cheap of a PSU. As affordable as Corsair and Antec units are, these days, there is no excuse for getting a crap PSU for a nice system.

Since XP 64 blows, again, do not consider XP a choice. Actually, since you want a gaming rig Linux probably isn't a choice either, unless you only want to play WOW and some other very popular or very niche titles (I have more Linux machines than anything else, but none of them are for gaming really, even though a few of them can run the odd game or two).

Really, Win 7 is the choice for gaming at this point, if you're spending money on 64bit CPUs specifically for gaming, there's only one 64 bit OS that does gaming well: Win 7. Home Premium is all you need, don't think you need that Ultimate crap.