HP Z840 WorkStation 719798-003 860478-001 DPS-850AB-1 A HP Computer Power Supply 850W

Can replace the following Part Numbers :

Fits the Following Laptop Models :

Why You Need A High Quality PSU ?

The role of a PC power supply unit is to convert the AC electric power that comes from the mains to the DC power that the computer requires. But it can do much more than that. A good quality power supply can make your system more efficient, stable and reliable.

Choosing Your Power Supply

Firstly, ensure you select a PSU from a reputable manufacturer.

Output

When choosing a PSU the output is very important. This output is listed as watts and should be greater than the combined wattage of all the components in your system plus 40 to 60%. Very simplistically speaking the more demands you place on your system the higher the wattage of the PC power supply unit should be. For example, a high end gamer will require a far higher wattage than a home user who surfs the net and does some word processing.

Energy Efficiency

But it isn't all about the wattage. Efficiency is important so look for PSUs that have the 80 Plus certification. This indicates that the PSU will waste less energy than other units making it cheaper to run and much more reliable.
PSU Cabling

There are different types of PSU and cabling. Fully modular power supply units enable the user to remove surplus cables from the case, whilst a semi modular PSU has a mix of detachable and hard wired, or permanent, cables.

The third option is a fully wired PSU which, as the name suggests, does not allow any cables to be disconnected. Of the three the fully modular unit is the most versatile.