I have been building computers for many years. It started back in the 1980's when I would take an IBM XT or AT machine and add performance enhancements or expansion hardware. I used to find it challenging to build high-performance workstations that were reliable. In the past few years I have stepped up the challenge to build PC's that are silent.
Making a PC run very quietly is a significant challenge. My first attempts were successful , but after a few weeks I began to have serious stability problems. You might be wondering why I am writing about silent PC's in the Data Backup and Recovery blog. Let me explain; the parts of the computers that make the most noise are the fans. That includes the CPU cooling fan, graphics card cooling fan, and power supply. Slowing those fans down or eliminating them will certainly make your computer quieter. You can also a quieten a computer by adding acoustic insulation inside the case. All of this leads to reduced airflow inside the case and hotter running components. Too much heat and the components will fail, sometimes temporary thermal shutdowns, sometimes actual damage occurs. Modern CPU's absolutely need cooling. Newer and faster Intel CPU's will shutdown within a few seconds without a properly installed heat sync. According to Toms Hardware, AMD CPUs will physically burn themselves up and irreparably damage the motherboard if the heat sync is not properly installed. When a computer system is not properly cooled it will be unstable at best, but even worse components can suffer an untimely death.
Any computer that is prone to locking up or spontaneously rebooting is also prone to data losses. Data integrity problems can occur on your hard disk as a result of sudden shutdowns. I will spare you the details of how that happens, but you should be aware that any sudden loss of power or ungraceful shutdown has the potential to corrupt data. In addition to the aggravation of an unstable system, there is a much bigger problem often looming. Hard disk drives require cooling also, when hard drives run at temperatures above the manufacturers tolerances, the data is subject to corruption and worse, the drive can completely fail.
I once experienced several untimely hard drive failures in the same machine before I discovered that my drives were not being adequately cooled. I had three hard drives mounted in a very tight area near the top of the case. I had also placed acoustic insulation around the drives to eliminate the drive noise. There was very little airflow around these drives. After I had three hard drive failures of fairly new models from different manufacturers I knew something was causing the failures other than natural wear and tear. I used a tool called Dtemp, which displays the temperature of your hard drives in the system tray area of Windows XP. I found that my drives were typically operating at 50C - 70C and sometimes exceeding 70C. I modified the case and added a 120MM fan at the top of the case to pull cool air across the drives. The larger fan pulls a higher volume of air at a lower speed than a smaller fan running faster, and with much less noise. For the past two years my drives have been running at between 26C and 38C. I have not had even a single hard drive failure since then.
You may have read that Google recently performed a study that shows that temperature may not be as big a factor in hard drive failures as once believed. Don't interpret this study to mean that you shouldn't be concerned about drive temperatures. Google's drives are all mounted in servers at professionally managed data centers. Those servers are built for reliability, which includes proper airflow. I think it is safer to say that temperature may not be a factor as long as it is within certain limits. I can assure you that I have had repeated experiences with hot running drives failing in less than one year, and I will never make that mistake again.
So, if you don't build your own computers then why should you be concerned? Many of the store bought computers designed for desktop usage are built to be as quiet as possible. The manufacturers are usually aware of potential heat problems and engineer their machines to keep the heat within limits. Problems occur later when you take the computer home and place in a tight spot under your desk with limited airflow. Or, when dust clogs the air vents or heat syncs. You should always make sure that your computer is positioned so that airflow is unobstructed on all sides of the computer where the case is vented. I also recommend that you occasionally unplug your computer, open the case, and carefully vacuum and clean out the dust.
Regardless of what you do to maintain your computer, you are only delaying the inevitable. Components will eventually fail. Hard drives are the most likely to fail because of the moving parts. You really don't know when a component might fail that will cause data-loss. If you have built your own computer and didn't properly design a cooling system, then your data may be even more at risk. Even if you bought a brand-name computer, your data is still at risk of loss for a variety of reasons. The only prudent thing to do is make backup copies of your data on a frequent basis.