It's easier than you might think to max out your desktop power supply, particularly if you have an off-the-shelf system with a large case and a low-wattage PSU. Even if you don't hit the maximum supported wattage rating, with enough extra drives and internal fans, you can all of a sudden find yourself without the necessary internal power leads for that lighting kit you've been eyeing. Here's where Add2PSU can come in handy.
Initially designed by David Lorentzen to add power to a home server, Add2PSU is a small circuit board that lets you daisy-chain desktop power supplies. Lorentzen says he has been awarded patent pending status on the device, and he hopes to have his online store running by the end of August, at which point he will sell the Add2PSU for $19.95.
As demonstrated in the video, you can use Add2PSU to chain together multiple power supplies in one computer, with Lorentzen claiming the ability to add a "virtually unlimited" number of PSUs. That makes Add2PSU appropriate if you need more power, like when you might want to add a dual-chip graphics card to a system with a low wattage power supply, or if you've simply run out of power connectors. Although the video shows a pair of Add2PSU's being used to add extra power supplies inside a desktop chassis, at least technically speaking you should also be able to add a power supply externally if your case isn't big enough.
Depending on your needs and you existing power supply, you might find that a buying a new, higher wattage PSU is actually a more economical solution than adding capacity with the Add2PSU and a second power unit, (you can buy two 500w PSUs for $50, or a single 1,000w PSU for $100, for example) so be sure to consider the overall expenditure, as well as the space inside your case. Still, we can think of many situations where an Add2PSU would be useful, and we expect many system building enthusiasts will welcome this product once it comes to market.