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Processing techniques of optimisation of operation PC

Evgenie Rudometov

Productivity and energopotreblenie the computer depends as on the controls built in in chips productivity, and from processing techniques realised in the motherboard architecture

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, for example, dispersal (overclocking). The idea of dispersal as rather simple and concerning a cheap method of rise of productivity before the bought or new computer, it is happy is simple. In its basis real possibility of maintenance of accessories in the forced frequency modes lays. And, as is known, rise of clock rates allows to solve tasks for smaller time or to handle great volumes of the information for a time unit.


Productivity = (Quantity of instructions) / (Execution time).

This expression can be copied in the form of product of quantity of the instructions executable for one clock tick (Instruction Per Clock, IPC), on quantity of clock ticks for a time unit (clock rate, F):

Kol-in instructions K-in clock ticks
Productivity =--------------------------h------------------------=
IPC x F K-in clock ticks Execution time

Thus, productivity is proportional to frequency. However, in a reality dependence is not strictly linear as because of high frequencies the part of the handled information is distorted and consequently transmissions should be repeated. Besides, is also a problem of synchronisation of operation of separate sites and subsystems that generates delays. Nevertheless, with growth of clock rates productivity grows also, at least, while the share of the distorted sendings and total size of delays will not stop this growth.

For maintenance of growth of clock rates of chips above a nominal as follows from physics, it is necessary to increase and levels of feeding powers that leads to growth teploobrazovanija:

P = C x V x V x F

Here, P – power teploobrazovanija; With – the coefficient considering features of the architecture of chips; V – a supply voltage; F – clock rate.

By the way, clock rate reduction allows to lower a supply voltage, and reduction of both these parametres according to the resulted formula promotes lowering teploobrazovanija. And it in turn, reduces load on cooling resources that allows to reduce speed of rotation of fans, to lower noise, to save the electric power (essentially in notebooks and servers).

For the sake of justice it is necessary to mark, that is far not all experts divide enthusiasm of adherents of the forced modes, though number of fans of dispersal highly enough.

Possibility of dispersal of the processor is grounded that the majority of processors have enough the big technological store providing the guaranteed performance level of all released series.

Appropriate technological spares of productivity often have also units of videoadapters (video chips and video memory chips), dynamic storage and hard disks. This store can be realised in the course of individual selection of an optimum behaviour of maintenance of dispersed units.

Despite aversion many experts and computer corporations of such phenomenon as dispersal, possibilities of handle of productivity continues to win popularity, increasing number of the supporters. Corporations-manufacturers of motherboards, carrying out the activity in hard competitive struggle, could not ignore opinion of potential buyers. For this reason appropriate functions are supported by the majority of their products.

Selecting the optimal motherboard by criterion of presence of functions of dispersal, it is necessary to estimate a number of the features providing implementation of given specific modes.

First of all, it concerns a band of operating frequencies of buses of the processor (FSB) and memories, and also step of their change. The matter is that, as a rule, modern processors have the fixed frequency coefficient defining internal frequency of operation of a kernel (kernels) of the processor through frequency of bus FSB. Therefore dispersal is usually carried out by increase in frequency of the bus of processor FSB. Thus it is necessary to consider, that the increase in frequency of the bus of the processor is quite often accompanied by respective alteration of frequency functional modes of other accessories.

And still units of dynamic storage and videoadapters are exposed to dispersal. Really, some copies admit substantial growth of clock rates, for example on 20–50 %. In extremal modes growth can be essentially above. So, for example, in experiments of deep cooling of working chips is not a rarity and doubling of clock rates.

As to traditional modes of dispersal of the central processor unit of the computer, how it was marked above, it is reached usually by increase in frequency of the bus of processor FSB. However its growth in some cases is accompanied by change of modes of other components of system. It can be, for example, disk drives on hard magnetic disks. For support of a safe operation and saving of the information for it does not follow considerably (more than 10 %) to increase clock rate of the bus of hooking up.

By the way, the modern qualitative motherboards released by manufacturers of a top level, allow to operate with buses of the processor, the videoadapter and hard disks independently from each other. It raises flexibility of customisation and allows to optimise operation of each of subsystems. It is carried out by individual selection of appropriate parametres at usage of all accessible resources.

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 increase in level of power of a kernel of the processor at 5–10 % (in qualitative products) at control support over temperature modes of maintenance of units.

It is necessary to mark, that for extremal modes at which maximum increase of productivity is reached, it is required considerably bolshee the increase in feeding powers quite often reaching of 20 %. Nevertheless, for support of maximum levels of dependability and safe ekspluatatsy it is expedient to abstain from modes with the raised levels energopitanija.

Change of frequency and powers can be carried out as by means of appropriate switches and crosspieces in motherboards of the previous generations, and program — in BIOS Setup. Certainly, the dispersal which is carried out by software, is much more convenient, as simplifies procedure of a choice of the modes providing maximum computer power. Thus, using possibilities of processing techniques of type SoftMenu in BIOS Setup, it is not required even to open a computer system unit. All operations on dispersal and the control over the installed parametres are carried out in appropriate BIOS Setup choices.

Hardware support of the given possibilities is carried out by the special chains setting frequency modes of the main subsystems.

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 the motherboard chips PLL uses for creation of several frequencies.

One of examples of implementation PLL, used, by the way, in motherboards of such known manufacturer as Gigabyte, is resulted in a Fig. 3.

Fig. 3. 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, provide ample opportunities for handle of productivity and energopotrebleniem.

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.

The most perfect complex variants of hardware-software handle allow also rather smooth change of levels of feeding powers and the time parametres, defining operation of units of a subsystem of dynamic storage.

As an example it is possible to result a number of the processing techniques used in motherboards of company Gigabyte, being one of leaders of the given sector of the market.

Speaking about controls it is necessary to mark such innovation as the dynamic dispersal providing automatic change of clock rates depending on change of computing load. Such resources provide growth of clock rates at increase in load and reduction — at its lowering that improves thermal modes of maintenance of accessories. As an example it is possible to result processing technique C.I.A. 2.

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 2), created Gigabyte and allowing to optimise operation with dynamic storage at the expense of the registration of characteristics of known chips/units. As show results of testing, besides increase in clock rates processing technique Memory Intelligent Booster 2, really, will involve the mechanisms promoting increase of capacity of the bus of memory.

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 program EasyTune 5 (and-or the newest EasyTune Center) for monitoring of system parametres and dispersal realisation (a Fig. 4). 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. And still it is necessary to mark customisation of modes in SmartFan: it is possible to select a band of a rotating speed from 0 to 100 % and temperature corresponding to boundary values.

Fig. 4. A choice of parametres C.I.A. 2 and an example of operation EasyTune 5

Certainly, in many models Gigabyte are available also appropriate resources of rise of clock rates of video subsystems. For example, in BIOS Setup of some models there are the parametres defining efficiency of processing technique Robust Graphics Booster. The essence of this processing technique is reduced to that by means of a choice of one of three modes — Auto, Fast, Turbo — the user has possibility to increase frequency of operation of a graphics kernel and graphics memory of a videocard.

And it is finite, in BIOS Setup numerous parametres of rough and-or thin customisation of effective operation of the main subsystems are provided. Change of frequency modes, supply voltages concern them, tajmingov memory modules, handle of fans, etc .

Considering firm hardware-software resources, it is necessary to recollect and some features of the architecture of motherboards. They allow to expand bands of handle and to increase functionality. Really, specialised chips together with a chip set provide support of firm processing techniques. And in some cases at the expense of careful study of the architecture and design of the card it is possible to weaken the limitations superimposed by chip sets, being, as a matter of fact, a basis of motherboards.

As an example it is possible to result Intel P965, 533/800/1066 MHz calculated for the processor bus . However on this chip set company Gigabyte has released models of motherboards not only correctly working with the processors which bus has frequency of 1333 MHz, but also supporting for them also dispersal functions. In addition to it with a chip set of Intel P965 it was possible even to expand possibilities of a video subsystem.

Developing the success received with sets of Intel P965, the company has released a number of models of the motherboards created on the basis of chip sets IntelP35. New products support the multinuclear processors working on higher frequencies. However, as well as in a case with Intel P965, implementators of motherboards have faced limitations videopodsitem. The matter is that IntelP35 not preduspmatrivajut the multipaid patterns realising processing techniques of type SLI and CrossFire.

However and in this case it was possible to find the appropriate solutions similar to that has been realised in the motherboards created on the basis of IntelP35. Really, in new models video subsystem support, as well as earlier, is carried out by presence of two конструктива PCI Express 16 plugs and appropriate interfaces (a Fig. 5). Switching of lines is carried out by means of two special chips (PCI Express Switch), integrated into structure of the architecture of the motherboard.

Fig. 5. Implementation of a pattern with two videocards in the systems created on chip set IntelP35

So video subsystem operation, for example, in motherboard GA-P35-DS3P is organised. In a pattern with two videocards support of processing technique ATI CrossFire — clone of processing technique SLI is provided . It allows to expand possibilities of a video subsystem essentially.

The first slot supports a high-speed mode х16. The second — not above х4. This slot is divided. It divides the common lines with PCI slots Express x1. As a result of its usage eliminates possibility of operation of arrangements PCI Express x1, that often is not critical, the considerable quantity of controllers is already integrated into motherboard structure. Changing number of videocards and parametres of their customisation, it is possible to change productivity of a video subsystem in a wide band of values.

Estimating the resulted solutions, it is necessary to mark, that the given browse does not apply for entirety. The spectrum of the firm processing techniques oriented to optimisation of computer possibilities, of course, essentially is wider.

In summary it is necessary to remind once again, that the choice of the optimal motherboard is very important stage. At this stage possibilities of the future computer are quite often pawned. And firm equipment rooms and software can essentially help with their extension.

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

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