Is there any difference between computer hardware brands? Does more expensive hardware last longer? What is the best value? When should you replace your hardware?
The original 1970s PCs were built in rack mount cases still in use today. The 19" rack mount was in common use in for radio in the 1930s and was used in railway systems for years before that.
The first modern PC from IBM arrived in 1980 and the case remained in use until 1995. The 1995 ATX format is still used today. If you buy reasonable quality metal cases, they will outlast everything else in the computer. The bits that will break are any plastic bits and the power supply, which is replaceable. If the case has built in front ports, the ports will become obsolete. You can plug in replacements.
Today I cleared out some old paperwork and found a note about an upgrade in January 1995. The upgrade was to a 486/30 with 8 MegaBytes of memory. I then donated the upgraded PC to a student. 1995 was the big switch from the 486 to the Pentium and it was worth starting with a clean new computer.
You can build computers today with the rack mounted cases dating from back before the 1930s or the
modern case from 1995. The metal cases for both could last 50 years.
The power supply
Cheap power supplies burn out in a year or two. Cheap power supplies burn out on the first hot day in summer. Slightly more expensive power supplies last five years. Any good brand, including Antec, will last longer than the processor, motherboard, and other components. Expect to use two or three power supplies across the 20 years you use the metal case.
Modern power supplies are more efficient. Look for the 80plus or higher efficiency mark. Good brands use big quiet fans. If your computer is on 24 hours a day, as in a server, upgrade to a more efficient power supply. If your computer is near your ears, upgrade to a quieter power supply. For everything else, use your existing power supply until it burns out.
Old power supplies needed excess power to allow for expansion and burned all that power even when not used. Modern power supplies burn only what is used. You can buy a power supply with lots of excess capacity for future expansion without the power supply burning up the unused power.
As an example, you might need 350 watts now and 600 watts in the future. In the old days you would buy a 900 watt power supply to supply the 600 watts and most of the 900 watts would burn all the time. Today you buy a more efficient power supply, 80plus, and need only a 700 watt power supply to supply 600 watt to the computer. The 700 watt power supply will burn only 420 watts when he computer is using only 350 watts. You save 480 watts now and 200 watts in the future.
Motherboards outlast their usefulness. Some cheap motherboards will burn up in a year or the first time there is a voltage spike through any connection. Good brands survive many years and you will throw them out because they are obsolete.
I usually buy gigabyte motherboards because the few extra dollars gives you many years of reliability, a good selection of modern features, and a choice of many models. I used Abit for a few computers and they were reliable but there was limited choice. There are a few brands I tried once and will not buy again because they broke so easily.
In Sydney, Australia, a good motherboard for a powerful workstation is about $150. The cheapest brands are only $25 cheaper for the same features and they will die in one year instead of five or ten years. The cheapest ones will have features that will never work reliably because the support chips were never tested properly. The cheapest ones will perform slowly because their are substitute chips that are not as fast as the rest of the board. The $25 you save on the purchase will be the value of the time you waste each week with intermittent failures.
I am writing this at a time when the Intel Sandybridge chipset saves you significant power compared to the equivalent AMD chips. At other times the AMD chips give you the best performance per watt of power and the AMD chips almost always give you the best performance per dollar. I use AMD most of the time and choose Intel today because of a specific combination of improvements made by Intel.
The top priced Intel processors are a waste for everybody except a few game players. A step down or two from the top is the best spot, the sweet spot, and is usually the fastest processor that works with the current motherboards and memory. The top one or two processors will spend most of their life waiting on memory.
The highest wattage processors are also the hardest to cool without busting your eardrums from the noise. There is usually a step down in power where the cooling fans can keep up with the heat without sounding like an air raid siren. If your computer is going to be in the same suburb as you, look at the quiet cooling options when selecting the processor.
On a recent voyage into a processor catalogue, the thousand dollar Intel options blasted out 135 watts of heat while the next step down the range produced only 90 watts. There were many cooling options for 90 watts. The 135 watt cooling options were few and required a separate room to store the heat exchanger.
If you are not playing some weird graphics intensive game, save a few hundred dollars on the processor, another hundred on the cooling fans, and spend it on faster disk storage.
A new processor every three years will keep the processor ahead of everything else in your computer. new processors with significant speed improvements always need new motherboards to keep the data flowing. Look for the second processor in each new generation because the first usually has limitations.