Thread: Power Bill for i7 with HD4890?

How many kw-hrs does the i7 build with one HD4890 graphic card consume every month? What percent is it in the total energy consumed every month? How much does it cost?

With one 4890, both of those PSUs are pretty large. I would use 750W for Xfire, but the 620W will be more than adequate for 1 GPU.

I checked the stats for Corsair power supplies over at 80plus.org. That's the site for the Electric Power Research Insitute that measures and certifies psu efficiency. All of the Corsair power supplies reach peak efficiency somewhere around 50% of load. So far so good. Peak efficiency for the models range anywhere from 80% to 90%. That's good too. The efficiency fluctuates but it is quite respectable over a broad operating range of about 25% to 100% load.

What's missing is a list of the rest of your components and some idea of what you plan to do with them. In terms of cost of actual electrical consumption as measured and billed by the electric company, you might want to consider the power draw at the electrical wall outlet (mains). Based on your components and what you do with them, how much electrical power will be drawn at idle, 50% load, and 100% load? How much of the time will you be operating at 50% load? Have you figured that out before looking at power supplies?

The power draw at the wall outlet is different from the power delivered by the power supply to the components. The power draw at the wall is usually higher and is dependent on the system components. The power delivered by the psu to the system components at 50% load varies from model to model. Which model delivers the correct power to the components to achieve peak efficiency at 50% load?

The 4890 video card itself uses about 45 watts at idle and about 125 watts at peak draw.

An Intel core i7 system with the 4890 uses a grand total of about 207 watts at idle and 287 watts at full load. That's the total power draw at the wall outlet.

Which Corsair power supply reaches peak efficiency for a system that draws 287 watts at the wall outlet during full load? The Corsair HX620. It reaches peak efficiency when drawing 364 watts at the wall while delivering 308 watts to the components. In contrast, the Corsair 850 reaches peak efficiency when drawing 475 watts at the wall and delivering 428 watts to the components.

Is it that simple? 364 watts versus 475 watts at the wall outlet? No. There is still the matter of efficiency over a broad operating range. The Corsair HX850 which is a Gold certified psu is more efficient when drawing 308 watts at the wall outlet than the Bronze certified HX620.

So, how much is it going to cost you to run your i7/4890 system, 15 hours a day for an entire year?