Do I really need a better power supply?

     Now if you don't take my word for it, all you have to do is read what AMD has to say about power supplies. Below is a quote directly from AMD technical documents regarding the use of power supplies that are compatible with the AMD Athlon XP processor based systems. I've left out the list of manufacturers, but I think you'll get the idea.

     From what AMD says in paragraph 3, it is quite possible that even your OEM AMD based computer may not have an adequate power supply. Makes you feel good about your OEM purchase doesn't it! This is why I build my own machines from scratch that way I know all the parts that are put in it are meant to work together. Anyway, choosing the right power supply has become an important issue for system builders. Gone are the days where we could just choose a power supply based on power output alone.

AMD Recommend, AMD Approved, P4 Compatible? What does it mean?

     The AMD recommend/Approved/Compatible power supply issue has been a very big pain in the back side for many system builders. It has been an even bigger issue with web sites like mine that give technical advice on a daily basis. Let me clear some things up about this issue. First off, let's start with the P4. As far as I know, there has never been a big issue with power supply compatibility with the Pentium 4. All you are looking for in a P4 power supply is the correct connectors. As most of you P4 owners know, the P4 has more than one power connector so the standard ATX power supply of yesterday will not work. Therefore, any P4 compatible power supply will do as long as it meets your power requirements. I always recommend that the standard P4 system should at least have a 300w Pentium 4 compatible power supply. If you have a system that is above and beyond the standard such as multiple hard drives, CD burners, SCSI devices and so on, use simple math to add up the power requirements of each extra device and add them to 300 watts. Lets say that your extra devices add up to another 50 watts, this means you should purchase a power supply with at least a 350w rating. Now this is not written in stone anywhere, this is just my personal recommendation. Besides, this is a very simple way to calculate your power requirements without spending days researching exactly what you need for every single component in your system.

     Now let's take a look at the AMD side of things as this is where it gets more confusing. When the AMD Athlon was first released, system builders soon found out that their standard ATX power supply would not work. In the first few days upon release, not even AMD knew why some power supplies worked and some did not. After the engineers researched this issue that found that most power supplies did not supply the appropriate power on the +5V, +3.3V, +12V, and +5vsb power rails. Power supply makers began testing their power supplies with the Athlon and if the system simply was able to turn on and function, it got the "AMD Approved" stamp. The unfortunate thing about this was that this stamp of approval did not mean that the power supply actually met AMD's standards. When the industry failed to meet AMD's standards, AMD took matters in their own hands and began testing power supplies themselves. This is where the "AMD Recommended" stamp came from. Unfortunately, testing every single power supply in production was a long and tedious process that would never be finished. Finally, the power supply industry realized that if they were going to sell any power supplies to the educated public, they had better meet AMD specs. Now days, you can pretty much bet that any power supply stamped AMD Approved on the shelf meets or exceeds AMD's standards. However, there is a world of difference between a generic power supply and what the hard core computer enthusiast should be using.

      As I said before there is only a few companies on my list of "high quality" power supplies and I will not recommend or use anything but the best. Now when it comes to calculating your power needs for your AMD system, use the same approach as I used above for the P4. Start out with the standard 300 watt power supply and work your way up. As long as you have a standard system such as what you see on the shelf at Best Buy, a GOOD 300 watt power supply will do just fine. But because most people who visit Club Overclocker do not own a standard system, 300 watts is not going to be near enough so calculate your power needs wisely and always round up to the next higher rated power supply.