Haswell compatibility with Corsair power supplies

A report recently published over at the VR-Zone discussing the new 4th generation Intel Core processors, code-named "Haswell", and their ability to go into a lower power sleep state than any previous processor has caused some concern about PSU compatability with the new processor.

When an Intel Core (i3, i5, i7) processor is idle, it goes into a sleep state that requires less power than when the CPU is active. Since the motherboard voltage regulation modules that provide power to the CPU gets their power from the power supply's +12V rail, these sleep states can dramatically reduce the load on the power supply's +12V rail.

Using Corsair Link to Monitor a Corsair AX860i Digital ATX PSU's Power Output, Temperature, and Fan Speed

Many Corsair power supplies feature cooling fans with Zero RPM technology. Essentially, while the power supply is at lower loads and producing less heat, the intake fan is stopped, therefore producing zero noise. As the load on the PSU increases, the power supply produces more heat and that heat needs to be evacuated. A thermistor inside the power supply tells the fan to kick on. Once those temperatures drop to a level that is safe for the power supply to operate without active cooling, the fan cuts off and the power supply runs silently once again.

For my demonstration, I will be using an AX Series AX860i Digital ATX PSU and Corsair Link software to demonstrate how the PSU's power output and temperatures increase with load, and how the power supply fan speed increases and decreases with that temperature.

Corsair and Infsite A.G. Dream PC

What components would you use to build your Corsair Dream PC? Corsair's Ronaldo Buassali recently visited Infsite A.G. in Brazil to build a Corsair Dream PC. Check out some photos of this awesome PC.

Why does a better power supply mean a better computing experience?

So how does a better PSU equate to a better computing experience? Consider this: If your power supply isn't doing a good job of regulating voltage and filtering ripple, what is?

The computer power supply essentially converts AC to DC. Older or more basic computer power supplies convert AC to multiple DC voltages (+12V, +5V, +3.3V) at the same time. Newer, more advanced power supplies, convert AC to +12VDC, while smaller DC to DC power supplies within the power supply's housing convert the +12V to lesser used +3.3V and +5V. The latter is more efficient because lesser used voltages are not converted unless they're required and converting DC to DC itself is more efficient than converting AC to DC as it requires fewer and smaller components.

After that voltage is converted, it's filtered with inductors and capacitors.

What's in the wattage?

When people talk about computer power supplies, there are a lot of terms that get thrown around that we here at Corsair realize that not everyone understands. Unlike a CPU or GPU, a power supply doesn't have clock speeds. A PSU doesn't have 4MB vs. 8MB of L3 cache. A power supply doesn't have 2GB vs. 4GB of GDDR memory. So what number does everyone know when they look at a power supply box? The wattage. But, truth be told, the actual capability of one power supply can't be explained by wattage alone. One 600W power supply may not be the same as another 600W.

First, let's talk about what this "wattage" number on the box and power supply label is. The wattage of a power supply is an indication of how much DC power the power supply can put out. But a power supply only puts out as much DC power as demanded of it by the computer. And depending on what you're doing with that computer, that number can vary a great deal. Even though you have a 600W power supply, the power supply may only be putting out 300W, or even as little as 1 watt if it's just sitting in standby.

Here's the rub: that maximum wattage number comes with a number of conditions. A number of conditions that aren't always laid out on the retail box somewhere. And, as a consumer, you don't know what these conditions are unless a power supply is properly reviewed and exposed as the fraud, for the lack of a better word, that it may be.

Corsair fully discloses that the GS600 is rated at 600W, continuous, at 40°C.