Board core voltage regulation combat guide

To improve chances of success overclocking and stability after overclocking, appropriately increasing the CPU voltage, is a key factor in the success of overclocking, which is often easy to overlook the rookie or dare not start with. When you overclock its successful launch, but the operation is unstable, if you will appropriately raise the CPU voltage a file, the problem mostly solved. In fact, as long as you have enough courage, the vast majority of the work of the nominal voltage of CPU is stable for more than 10% -15% level, except, of course enhance the voltage of things, and sometimes lower voltage can also increase the stability of overclocked, this was mainly due to the low voltage reduces the CPU power and heat (such as the latest Athlon 4, the nominal voltage is 1.4V, but a lot of data reporting can be a 1.3V). Finally a CPU at what voltage and stable operation of the need to grope in practice. But at present a lot of motherboards, especially some models slightly older motherboard, because of their CPU power circuit design constraints, only a relatively limited range of core supply voltage within the regulation, which requires us to supply to the CPU on the motherboard the circuit to do some modifications before they can get what we need core voltage. Today, I tell you about the common Jiuji motherboard modification method.

1. Core voltage adjustment principle

First, we must first familiarize ourselves with the current CPU power supply circuit board design principle, the early motherboards, everyone on the motherboard CPU socket location to see huge heat sink, when using traditional sub-pressure type regulator circuit consumed in the power tubes are more useless power, with the rising demand for CPU power, useless waste of power consumption is even more obvious, but also to the power tube cooling caused great difficulty. So, starting from about the Pentium MMX, most of the motherboard CPU power supply circuit has been replaced with the exchange of design, when there is no notable feature is a large heat sink, because the high efficiency switch mode power supplies ah! Board by the Switching Regulator (Switching Regulator) on the CPU core power supply, switching regulator is located beside the processor socket, mainly by PWM (Pulse Width Modulation) integrated circuits, power transistors, voltage regulators, jumpers, resistor divider , filter capacitor and a number of external components, of which PWM is the key, the size of the direct control of the pulse width modulated output voltage reference level.

I do not need to discuss switching regulator works, I just want to first of all tell us about the voltage regulator part of the core voltage and VIO voltage generally use a single jumper (One Jumper) design, that is, hopping through the cap with a short jumper from one group of the different location, connected to different sub-pressure resistance, see the diagram below, from the PWM section 14 feet (This pin’s function is to provide 5V reference voltage) share a different reference voltage, and then with the sample from the output of the voltage comparator, and then feedback back to the internal PWM error amplifier to adjust the pulse width to achieve the purpose of regulation, it is clear that the resistance of several resistors. is to determine the output voltage level of the key factors.

ASUS A7V-133 Motherboard CPU power supply schematic



According to this working principle, to change the voltage of the most direct way is to change the divider resistor values, but because of the motherboard on a chip-type resistors generally have been welded on the motherboard, and rely on our amateur DIYer iron tool is difficult to be welding, the re-welding a new resistance to the destructiveness of a larger board. Originally, the chip resistors in fact not used up to do soldering iron! Therefore, in this top brains appear to a dead end. Also must devise new strategies Creek Trail: intelligent thought DIYer can use the feedback principle, in general, the output voltage is 1.85V, the feedback voltage is 1.85 so that we can maintain output voltage stability. If the feedback power less than 1.85V, then the chip will improve response to the output voltage to return to 1.85V output. So an appropriate artificially inflate or reduce the feedback voltage, so that the internal PWM error amplifier (mistakenly) thought that the voltage is high or low, and thus reduce or raise the reference voltage value, as we increase or decrease the purpose of core supply voltage. The increase or decrease the feedback voltage is very simple, as long as the power series with resistor from +5 V to ground, and then partial pressure can be either directly receiving voltage feedback terminal. However, this approach is flawed, or the constant voltage range (currently the majority SOCKET A motherboard is the nominal core voltage range of 1.5 and 1.85 V, a small number of the minimum can reach 1.1 V,), changing only the beginning and end of The voltage value, of course, little impact on the use of this, after all, only for the specific user may use a CPU, not-for-3 days 2 days or upgrade the CPU used to.

二. Common methods of several board changes

Motherboards currently on the market the brand and model number, but they are used in CPU power supply circuit PWM (Pulse Width Modulation) IC also so few, and we adjust the core voltage is mainly to change the normal feedback voltage to the pulse-width modulation integrated circuit . Therefore, the main changes vary with the different PWM. Here we have according to use PWM to analyze how the different changes, but also tell you that for each different PWM, which motherboard is used.

1. Modify the pre-prepared

The specific hands-on before I once again remind you that you must have basic soldering skills, electronic components, the choice of soldering iron and solder must be carefully selected, see figure below, due to solder wires directly to the PWM feedback Manifold end, so it must be To prevent static electricity, welding iron must be grounded or the power outages, and time can not be long. Otherwise, you must reimburse the PWM, you also honor the motherboard. Is that they are not experts, please repair the TV will be a welding teacher to help look. Resistor voltage divider used in general is best to use a linear variable resistor, see below left:

Adjustable resistor selection can not be sold on the street electrical repair shop where a few more pairs of adjustable resistance, which is used in radio and TV volume control, which we should pay attention to, otherwise your CPU may be inadvertently Xiang Yu extinction between the loss (resistance value of stepping too quickly lead to voltage sudden liters). Adjustable resistance among soil colored red pins and then solder the wires connected to the voltage feedback terminal, and the other painted black directly to ground, generally speaking you just installed in accordance with standard method of loading the machine, the chassis is the best way. This resistance is adjusted in a clockwise direction to enhance core voltage, counter-clockwise is to lower the core voltage. Conditional best digital multimeter to monitor what folder to prevent any eventuality.

2. Common Manifold modification of several pulse-width modulation method

① HIP6301

The chip is mainly used in support of the AMD SOCKET A series of motherboards, the use of motherboard is very large, there is a certain representation, mainly: Abit KT7, KT7-Raid, KT7A & KT7A-Raid; IWIll KK266 & KK266-Raid; Epox 8KTA3 ( new version), Asus P4T (the only INTEL chipset motherboard), see below:

First of all we have to find it the feedback voltage input pin numbers for the 10 pin is the feedback voltage input (which was painted green), but it was also suggested that the first seven feet, the feedback voltage input terminal, is actually wrong, though The pin does have certain feedback effects, but it is only a small effect on the output of the scope of changes, but in the major remedy shortcomings in the chip design on a number of shortcomings. Impossible to confuse the chip from the error amplifier circuit testing role. In general we focused on the chip, concatenation 50K adjustable resistors, variable resistors be welded on one end of the wire connected to the first 10 feet, on the other side of the welding wire is also connected to the motherboard ground. Of course, a different voltage is required to achieve the same motherboard resistor values are different, can be measured using a digital multimeter look, this approach could be to the maximum core voltage 2.6v. Of course, if your motherboard uses this approach not work, you can also try the 30K resistor in series with 7 feet and between our approach, after all, you can adjust the output voltage range, but did not the author describes this range is far greater, have information on this method only to the maximum core voltage of 2.2v (depends on motherboard model).

We are more representative, Abit KT7A an example to show how, see below:

We K7TA motherboard with Duron 600 to do the test. Changes before the CPU core voltage to maximum 1.850V, to provide a steady run on 972 MHz (108 * 9.0). To 988 MHz can only be entered WINDOWS sky and white clouds, and then died. Modified, CPU core voltage is transferred to 2.07V, to provide a steady run on 1020 MHz (102 * 10),

The author lists the following before and after modification of the core voltage of the actual value comparison for your reference:

Revising the previous Vcore -> modified Vcore

1.500V -> 1.70V

1.575V -> 1.78V

1.650V -> 1.87V

1.675V -> 1.89V

1.700V -> 1.92V

1.725V -> 1.94V

1.750V -> 1.97V: 1000 MHz

1.775V -> 2.00V: 1010 MHz

1.800V -> 2.02V: 1010 MHz

1.825V -> 2.04V: 1010 MHz

1.850V -> 2.07