2. Haswell using the new power supply standard, the need to upgrade existing power
Haswell has done a lot of improvements for energy conservation
The Haswell processor for energy-saving made many improvements, including C6/C7 saving state required the reduction of the current. There have been too much processor power, the problem of shortage of power supply, and now the current is too large will be a problem. The existing ATX power supply with Haswell what problems will arise? What kind of power supply in order to meet the needs of the Haswell?
The Hasell supply improved
Earlier today, we reported Haswell processor for energy-saving done a lot of improvements, including C6/C7 saving state required the reduction of the current, minimum current requirements reduced from the current third-generation Intel Core processor 0.5A to ten one of the stars, only 0.05A. We finally came to a special period of time, used to be too much processor power, shortage of power supply, and now is the minimum current is too large. Using existing ATX power problems that will arise? What kind of power supply in order to meet the needs of the Haswell?
The Haswell minimum current requirements from 0.5A to 0.05A
The current Intel ATX12V v2.31 design guide book from the Lynnfield period for the processor power supply +12 V2, all the way to the minimum requirements of the output current is 0.5A. Intel has not released an updated design guide book, but this is related to the electrical characteristics of the power supply itself is not a design specification can be solved, our analysis together.
Intel ATX12V V2.31 specification of 300W power output requirements
Low current to reduce problems that may occur
Haswell processor to enter C6/C7 power-saving state, the +12 V2 the required current will be greatly reduced, and a host of other accessories will enter a power saving state to reduce power consumption. Mainstream power supply +12 V2 with +12 V1 is in fact the same route, this time need to focus on not just the load on the +12 V2 +12 V, but the total load.
Single magnetic amplifier power, for example, if the +12 V total load is too low, the power supply may be from the continuous conduction mode (CCM Continuous Current Mode) into the discontinuous conduction mode (DCM, Discontinuous Current Mode), in the continuous conduction mode into discontinuous conduction mode, the same duty cycle will result in a high voltage, in order to stabilize the output voltage in this case is necessary to significantly reduce the duty cycle of the +12 V drop back to normal, but this time +5 V the voltage will follow the decline may occur when stabilized +12 V High +5 V low.
To conclude, a single magnetic amplifier, dual magnetic amplification and DC-DC power supply will appear the following conditions:
The magnetic amplification: +12 V and +5 V output voltage significant changes possible +5 V is pulled low;
Dual magnetic amplification: In addition to the +12 V, +5 V and +3.3 V output voltage may be pulled low;
DC-DC: +5 V and +3.3 V low-voltage two-way will not be affected, of course, the power advantage here;
The output voltage is too low may occur is to crash or the host can not wake up from a power-saving state. The introduction of the the magnetic amplification technology, and the DC-DC technology can refer to our article: " PC power supply Introduction and advanced, from the magnetic amplifier voltage stability of the technical talk , Super annual Juxian: seven high-end power Hengping The test papers , DC-DC output technology introduction. "
Actual use readers can go back and read sections of the power evaluation cross-load point A light load, a power +12 V total load point A fixed 5.8W (12V2 output 0.242A) look the brightest voltage. The following example is some time before our silver the Yan ST45SF-G watch point A abscissa load 5.8W.
450W power supply cross-load pull out the chart, pay attention to point A
Cross-load performance DC-DC power supply low-pressure two-way will not be affected at light loads
Conclusion: ATX power Haswell is not a big problem
As host of other accessories, including motherboards, graphics cards and hard disk more or less there will be a certain load, the total load of +12 V at light loads generally are higher than our test point A. So small that the current ATX power Haswell processor will not be much of a problem (cottage power, and our evaluation of cross-load failed except). We can safely open the processor C6/C7 energy saving, voltage output deviates too big or system instability, show, you can try to pick a few +12 V chassis fan to increase the +12 V load power supply out of discontinuous conduction pass mode in order to solve this problem.
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