AMD Athlon Buyer's Guide - Part 4: Power Supplies

As we discussed in Parts 1 – 3 of our Athlon Buyer’s Guide, stability has been and will continue to be a major factor in determining the success of AMD’s Athlon platform.  Ever since the introduction of the Athlon in August 1999, users have definitely been skeptical about the platform’s compatibility and stability, especially after a number of horror stories surfaced dealing with some AGP video cards not working properly with some Athlon setups.  This brought back all too many memories of the days of the Super7 platform and, for AMD’s sake, we hoped that the stories were nothing more than that - stories. 

It turns out that most of the problems that users experienced with their Athlon setups were due to compatibility problems and other very solvable issues.  NVIDIA released a special driver update for Athlon users that were having problems with their GeForce cards.  While the driver update effectively disabled AGP 2X on Athlon platforms, it did make the GeForce a viable option for the Athlon platform.  In order to help promote a positive name for their Athlon platform, AMD worked overtime in creating and releasing their own list of recommended peripherals for use in an Athlon based system.  The idea behind this was that if you followed AMD’s recommendations, you’d be able to build an Athlon setup that is just as stable and reliable as any comparable Intel based solution.

The recommended peripherals ranged from cases and heatsinks down to power supplies.  But when was the last time you worried about your power supply when simply upgrading your CPU?  This was unfortunately the mentality that many Athlon upgraders had as they re-used their old ATX cases and power supplies with their new Athlon setups.  It didn’t take long for “AMD sucks” threads to erupt all over newsgroups and message boards as users blamed their unstable Athlon systems on AMD’s processor and failed to take into account other components as possible causes for the problems.  You can’t really blame the users in this case, because for the most part, power supplies have never been big issues with CPU upgrades.  Then again, we’ve never had a desktop CPU with 22 million transistors.

The Athlon is a very complex CPU and because of that complexity, it tends to draw more power than most Intel CPUs.  The high transistor count of the Athlon is the main culprit for the high power requirements of the CPU: the more transistors you have, the more current your CPU is going to draw.  This not only puts a strain on your power supply, but also on your motherboard, which is part of the reason why we didn’t see as many Athlon motherboards at the launch of the CPU.  Luckily, the motherboard manufacturers seem to have perfected their designs to a level that motherboards are no longer a major issue when determining the stability of an Athlon platform (as long as they’re on AMD’s recommended motherboard list).  This leaves the power supply as a potentially major cause of system instability if it isn’t able to supply enough power to the motherboard. 

A quick visit to AMD’s recommended power supplies list reveals over 40 recommended power supplies, as well as the following disclaimer:

AMD makes no representations or warranties with respect to any information provided on this web document relating to the products of other companies, and expressly disclaims any implied warranties of merchantability, fitness for a particular purpose, or non-infringement with respect to such products. Furthermore, the inclusion of such information does not constitute an endorsement by AMD of the product.

So if AMD isn’t in the position to recommend a particular power supply or two as being the best of the best, we decided to give it a try.  We managed to round up 11 power supplies, some of which are on the recommended list, others that aren’t¸ and put them through our own set of stability tests.  It turns out that even some of the power supplies on AMD’s list weren’t able to cut it in our tests.  But before we get to the tests let’s take a quick look at how much power the latest CPUs actually use.