Controls for productivity and energopotrebleniem

Evgenie Rudometov

Rudometov@rudometov.com

For rise of an overall performance of computer subsystems various controls for productivity and energopotrebleniem use

Controls for productivity and energopotrebleniem find the increasing distribution. The built in chains providing reduction of clock rate at lowering of computing load, the supply voltage allows to reduce, and reduction of both these parametres promotes considerable lowering teploobrazovanija.

As an example of effective remedies of handle of productivity and optimisation energopotreblenija (and, therefore, and lowerings teploobrazovanija) it is possible to result Intel processors. In their structure following resources are realised:

·         the Detector of an emergency overheat (catastrophic shutdown detector);

·         the Mechanism of automatic thermal monitoring (automatic thermal monitoring mechanism) — Thermal Monitor 1 and Thermal Monitor 2;

·         clock rate Modulation by inquiry (software controlled on-demand clock modulation);

·         Processing technique Enhanced Intel SpeedStep.

The detector of an emergency overheat — the full automatic mechanism for the first time appeared in processors of P6 set and realised also in processors of Intel of Pentium 4, Xeon and Pentium M. On reaching of the certain temperature threshold installed at manufacture of the processor, operation stops before arrival of special signal RESET #.

Thermal Monitor 1 (TM1) — the mechanism which has received the widespread name "trottling" (Throttling or Thermal Throttling, and also Thermal Trip). It is realised in processors of Intel of Pentium 4, Xeon and Pentium M. Represents a combination of the second temperature sensor control (the first is the mechanism of emergency disconnecting), also the processor calibrated at a fabrication stage, and the mechanism of modulation of clock rate of the processor.

Modulation of the clock signal submitted on the processor system of the thermocontrol, is resulted in a Fig. 1.

Fig. 1. Modulation of the clock signal submitted on the processor system of the thermocontrol

Unlike the detector of an emergency overheat, mechanism TM1 is both defined, and inspected by means of special instructions. According to Intel guidelines, mechanism TM1 should switch on in BIOS at initialization of the processor and not vary subsequently with the operating system. In case of a non-staff situation, for example, to a cooler stop, the mechanism provides maintenance of temperature of the processor at as much as possible safe level by means of lowering of its productivity.

Thermal Monitor 2 (TM2) — more perfect mechanism of protection of the processor from an overheat, realised in processors of Intel of Pentium M, and also in the improved models of Intel of Pentium 4 and Xeon. Essential difference from TM1 is handle of frequency (more precisely, FID — a multiplier of frequency of the system bus) and feeding power (VID) the processor. At the expense of lowering of feeding power, TM2 allows to save the big productivity of the processor in an overheat situation at identical lowering of level of the electric power consumed by it. Responsibility for usage TM2 is assigned on BIOS.

Mechanism TM2 inclusion is recommended for high models of processors, for example, for models not less than 2.8 GHz at clock rate of the bus of 166 MHz and not less 3.6 GHz at clock rate of the bus of 200 MHz. For low models it is recommended to use TM1. Simultaneous inclusion or turn off TM1 and TM2 is a non-staff functional mode of the processor and it is not recommended the manufacturer. Installation of target values FID and VID should occur BIOS at a stage of initialization of the processor.

Clock rate modulation on demand (ODCM) provides program reduction of thermal load by the processor during its idle time. The program job of a minimum level of a cycle of efficiency duty of the processor at the expense of processing technique of program modulation of clock rate of the processor (trottlinga) is provided.

Processing technique Enhanced SpeedStep (EIST) provides energosberezhenie, and, therefore, and low teploobrazovanie. Initially it has appeared in processors of Intel of Pentium M. Has come in the stead processing techniques of Intel SpeedStep, ispolzumoj in transportable processors of Intel of Pentium III and Pentium 4. More perfect processing technique provides more effective handles energopotrebleniem the processor by means of dynamic change of digital states of productivity of the processor (P-state transitions, everyone P-state is set by a combination of values FID and VID).

Are not left by implementators of the specified resources and modern multinuclear processors, the majority from which form on the architecture of Intel Core. Them concern dvuhjadernye Intel Core 2 Duo and chetyrehjadernye models. By the way, upper two - (a Fig. 2) and four-nuclear models support all earlier considered processing techniques of handle of productivity and energopotrebleniem. Them concern: processing technique of handle of productivity of the processor on demand of Enhanced Intel SpeedStep (EIST), functions of protection of the processor from overheat Thermal Monitor 1 (TM1) and Thermal Monitor 2 (TM2), processing technique of modulation of clock rate of the processor on demand of On-Demand Clock Modulation (ODCM), and also the improved modes of idle time Enhanced C States (CxE).

Fig. 2. The processor of Intel Core 2 Extreme X6800

In multinuclear processors of bars of Intel Core 2, and also in transportable processors of Intel Core Solo/Duo, the last function has been expanded on a case of all possible states of inactivity of the processor, including modes Stop Grant (C2), Deep Sleep (C3) and Deeper Sleep (C4). For desktopnyh processors of Intel Core 2 mode Enhanced Halt (C1) State — C1E is by default included only . It is linked by that deeper modes of "dream" of the processor, as a rule, do not use in desktopnyh platforms. So, for example, thanks to mode C1E the rated frequency of a kernel of the processor "is dumped" to a minimum level — 1600 MHz (clock rate of the bus of 266 MHz, the minimum multiplier 6x).

Estimating the enumerated processing techniques, it is necessary to mark, that it is necessary to carry to controls for productivity and resources and processing techniques of rise of clock rates. As is known, at rise of clock rates productivity increases. The method of rise of clock rates has received the name overclocking (dispersal).

Possibility of dispersal of chips it is grounded that the majority of them have the considerable technological store providing the guaranteed performance level of all released series. Processors, video chips concern such chips, chips of memory and even hard disks, for example. Their frequency technological store can be realised in the course of individual customisation.

Estimating this possibility, it is necessary to mark, that ideas of handle of productivity are popular for considerable number of potential users. Corporations-manufacturers of the motherboards which majority of products are supplied by appropriate resources should consider this circumstance.

Speaking about frequency customisations, it is necessary to mark, that the important characteristics, defining razgonnyj motherboard potential, smooth change of power of a kernel of the processor, and also power supply of DRAM units and video buses of type PCI Express or AGP is. Thus it is considered admissible and rather safe increase in level of power of a kernel of the processor at 5–10 % at support of the control over a temperature mode of maintenance. Nevertheless, for support of maximum levels of dependability and safe ekspluatatsy it is expedient to abstain from modes with the raised levels energopitanija.

As a rule, now all operations on dispersal and the control over the installed parametres are carried out in appropriate BIOS Setup choices or activation of appropriate program units.

Hardware support of the given possibilities is carried out by the special chains setting private modes of the main subsystems. One of circuits of creation of clock rates for the main subsystems of the computer is resulted in a Fig. 2.

Fig. 3. A variant of the circuit of creation of clock rates for the main subsystems of the computer

For flexible handle of productivity designers create the different variants, allowing change of possibilities of change of the coefficients setting a relation of frequencies of buses of the processor, memory and, probably, the videoadapter.

Change of frequency modes is carried out by means of the motherboards of special resources built in the architecture. Chips PLL concern their number (phase-locked loop), realising in the structure current-controlled or power of generators (VCO — Voltage Controlled Oscillator), carrying out constant tracing of a phase of an input signal. Such generators use for handle of frequency. On motherboard PLL uses for creation of several frequencies.

One of examples of implementation PLL, used, for example, in motherboards Gigabyte, is resulted in a Fig. 3.

Fig. 4. A variant of implementation of the circuit of chip PLL

Electronic chains with hardware-software change of the frequencies submitted on the main subsystems of the computer, provides ample opportunities for controlled dispersal.

Similar solutions are applied, for example, in models of motherboards of such known manufacturer as Gigabyte. Clock signals changed on frequency move on the component of a chip set fulfilling functions North Bridge through which administration in high-speed parametres of the processor is exercised, units of dynamic storage, videoadapter. Thus for stability rise, in the most perfect models possibility of smooth change of levels of feeding powers for the main subsystems of the computer is provided.

Speaking about controls it is necessary to mark existence of the firm processing techniques providing handle by productivity of the main subsystems. As an example it is possible to result a number of processing techniques of company Gigabyte.

Processing technique C.I.A. 2 (CPU Intelligent Accelerator) carries out dynamic change of frequency of the processor (more precisely, FSB) and supply voltages depending on current loading. The choice of one of dispersal modes is possible: Disable, Cruise, Sports, Racing, Turbo, Full Thrust. Each of modes defines a band of a gain of clock rate.

One more tool of rise of computer power are firm resources of improvement of operation of a subsystem of memory. As an example it can be considered M.I.B. 2 (Memory Intelligent Booster) from Gigabyte, allowing to optimise operation with dynamic storage at the expense of the registration of characteristics of known chips/units.

It is necessary to add, that the specified processing techniques are supplemented with a set of firm utilities from the same manufacturer of motherboards. Their structure includes, for example, program EasyTune 5. By means of this program it is possible to carry out a number of operations, such as monitoring of system parametres and dispersal. For users well change of frequency and a factor of the processor, a factor for memory, frequencies of bus PCI Express and a supply voltage of the processor, memory and the southern bridge of a chip set, but in smaller limits, is rather than accessible from BIOS.

Certainly, in many models there are also appropriate resources of rise of clock rates of video subsystems.

In summary it is necessary to remind, that the motherboard choice substantially defines possibilities of the future computer.

At article preconditioning book substances have been used
«Motherboards and chip sets. 4 izd. PC anatomy». — SPb.: Peter, 2007. — 368с.