Some of the bare basics to know before you plan a custom open loop is to know your rig’s power requirements. The online PSU calculator at OuterVision PSU Calculator part list will help you to get the non-overclocked load demand of your setup.

Below, is an example outcome. It is actually my own build that I have tested here.

Type Item
Motherboard Desktop
CPU 1 x Intel Core i9-7960X
Memory 8 x 8GB DDR4 Module
Video Card 2 x NVIDIA GeForce GTX 1080 Ti
SLI / CF Yes
Storage 3 x M.2 SSD
Storage 3 x SSD
Optical Drive 1 x DVD-RW/DVD+RW Drive
Computer Utilization 16 hours per day
Gaming/Video Editing/3D Rendering Time 2 hours per day
Monitor 1 x LED 37 inches
Load Wattage 789W
Recommended Wattage 839W
Note: Standard keyboard, mouse, and 8 hours of computer utilization per day already included in calculations.
Generated by OuterVision PSU Calculator 2018-03-22 11:05:11

What is missing in this calculator?

I wonder if they considered the power requirements of cooler / fans, pumps, connected USB devices, etc.

The other part of the outcome I do not agree with is the recommended PSU size from the calculator. It seems like the just add 10% on top of the load wattage.
Let compare this to another use case. You buy a fast car, and it can go 250km/h. The recommended tires on the perfect surface you put on this car is rated 275km/h. This margin is too small for me.

Another factor to keep in mind is that you are utilizing your PC on 90% of its rated capacity. Shame on you!

Statement on other site like this:

“But such a high power system won’t do anything much better, other than costing you handsome money.”

I also do not agree with.

PSU’s are the most efficient at ~50% of there rated max. So on a PC with the above rated 789W, I will install a 1500W – 1600W PSU. Therefore, under normal non overclocking scenario’s the PSU will be running at its “sweet-spot”. The remaining overhead is then for those overclocking days.

Remember: A 1200W PSU will not be using 1200W from your electricity wall socket if it is driving only 500W. It will be just a small % more than 500W.
(Look at the PSU’s efficiency rating to calculate this)

When overclocking, you should also research the power draw of the equipment when overclocked. Running faster and at a higher voltage as designed, the power draw will be higher. This is different for each MB and CPU design. In the case of x299, even small amount of overclocking have a big impact on power consumption.

Leave a Comment

Your email address will not be published. Required fields are marked *