CPU time = (CPU execution cycles + Memory stall cycles) x Cycle time  Processor performance traditionally outpaces memory performance, so the memory system is often the system bottleneck. The equation is named after Joseph Boussinesq, who rst derived it in response to John Scott Russell’s observation of the "wave of translation" (also known as a solitary wave or soliton).  For example, with a base CPI of 1, the CPU time from the last page is: CPU time = (I+ 0.2 I) x Cycle time  What if we could doublethe CPU performance so the CPI becomes 0.5, but memory performance … 0000000596 00000 n 1. CPU Performance Decomposed into Three Components: † Clock Frequency (`) Determined by technology and in°uenced by organization. t: Cycle time. CPU Performance Equation: ACA- Lecture CPU Performance Equation: ACA- Lecture Execution Time (T): T: CPU time (seconds/program) needed to execute a program. <>/Font<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 1024.08 768] /Contents 10 0 R/Group<>/Tabs/S/StructParents 1>> CPU Time = I * CPI/R. Noor Mubeen, Intel. T or R are usually published as performance measures for a processor. These combined to form CPU Performance Equation tT = 1 ` £CPI£IC, CPU Clock Cycle (This equation is commonly known as the CPU performance equation) (executed, I) CPI = Cycles Per Instruction Executed (I) 0 This equation can then be rearranged to find the volume of the CSTR based on the flow rates and the reaction rate: From the definition of conversion, F A = F Ao (1-X) or F Ao - F A = F Ao X, so the equation can be rewritten: Back to the Solution. (pD��+�\�b �9��@�PȞ��c 0000006470 00000 n 164 0 obj <> endobj 10 0 obj † Clocks per Instruction (CPI) Determined by ISA, microarchitecture, compiler, and program. 02-2. 3. trailer Many processors expose performance-monitoring counters that help measure 'productive performance' associated with workloads. Background loop with an “observation” variable. T = Clock cycle time. startxref CPU Time = I * CPI / R. R = 1/T the clock rate. Frequency of FP instructions : 25% Average CPI of FP instructions : 4.0 Average CPI of other instructions : 1.33 Frequency of FPSQR = 2% CPI of FPSQR = 20 Design Alternative 1: Reduce CPI of FPSQR from 20 to 2. Analysis of CPU Performance Equation • CPU time = Instruction count * CPI / Clock rate • How to improve (i.e. 1. 02-1. The exponential processor transistor growth predicted by Moore does not always translate into exponentially greater practical CPU performance. b. ��2���~�*�����;K)��ú���=���b��q�b���#a�ZZ5%د��5G7�����1�5���RzMO�d�����X���=�?U!�T@MYG4ӝ|� �v���#*��a�({�b=/�Y��XA���%\��ro��:L&ȴ��d�+�?H��K,�҇��5��׭������|�b̝�E���Fqr��=p>�)�d��jo��G����l��j����4�v��2��K������Ⱦ�?�����7LSݬZb��F��v��ޝ���X���h�`r�p|��˷��dW�#�b!�D{�e� ��D�+���ky����I{��k���3 W\'2q�O�|ƞ`W��x\2��Gw�K�"i�UϏ��m��+��8��q�&�o�u���9$-�M�QJ֢eFx�������� Here, R = Clock rate which can be measured by the inverse of Clock cycle time that means, R = 1/T. 0000001291 00000 n 8 0 obj endobj The main idea is to represent machine performance and program execution in terms of a high level abstract machine model. endobj CPI = Clocks needed to complete an instruction. The performance of a Processor depends on Instruction count, parameter and C view the full answer. T = N X S / R . stream %PDF-1.5 20% of the dynamic instructions in an application are multiplies. CPU Performance Equation Time for task =C T I C =Average # Cycles per instruction T =Time per cycle I =Instructions per task Pipelining { e.g. %���� CPU Performance Equation. If 30% of the execution time may be the subject of a speedup, p will be 0.3; if the improvement makes the affected part twice as fast, s will be 2. 0000002218 00000 n 0000001647 00000 n <> decrease) CPU time: Many potential performance improvement techniques primarily improve one component with small or predictable impact on the other two. ȓ�4�Qg��8@�:|��Q���@��@J�п���s�:��F�����$��܉�I�͞�����j����%�qR�����O�--��f� ��'|O�~ NM�\44k�a�K�u��dJAxLI �o](݅",o3��L��I�o`n\gn���d{�O� d�uqQ�o���f����T/�꼪�I�f8��8�%��k~�o��ñ{�oV�Ia�� CPI: Cycle per Instruction. 0000002577 00000 n 4 0 obj 0000002500 00000 n Basic Performance Equation. CPI = average cycles per instruction. t=1/f, f=clock rate. 2 0 obj H��W�r�H}�WtռH)�f_I�*Y�k�T��-+��d����()�q�c�{� ݼH���gL��F�i���u�l�䟶���߮��i#��Y��T%������H���lʢ�H�o���4�΋+�����?�� ��*���x'>���Edt�(�R�m�N8����EIl]�8|��V��d�ʄ*�#���`[O!���=��*б*㕉9~������|>W�6���9?�DX�?l��%�`�Z�q͒8I�L�Kl��G��ˋk1����$����KzM81�%�t2{B�l_C;%�� A new processor cuts the CPI for multiplies from 10 to 5 but increases the cycle time by 10%. endstream The equation would be: f~�p��La���"e��q�� ���4��e���-)��y��8P��L�,ۿ�'�������B$���t-�N�P�ptx�X��ьG�xBU��\���lʳ��j�����&��Lԑ� What factor(s) can impact those variables? endobj The instruction count in the performance equation is the “dynamic”instruction count. CPU Performance Equation - Example 3. since the clock rate is the inverse of clock cycle time: CPU time = Instruction count *CPI / Clock rate . <> Performance Equation - I CPU execution time = CPU clock cycles x Clock cycle time Clock cycle time = 1 / Clock speed If a processor has a frequency of 3 GHz, the clock ticks 3 billion times in a second – as we’ll soon see, with each clock tick, one or more/less instructions may complete If a program runs for 10 seconds on a 3 GHz processor, how many clock cycles did it run for? <>>> x�b```f``Z������ Ā B�@���1&�( py��uN��8�q0�a�c0R����˰��R���1�A�A�AiSt���Nz:WX'1VH[#���`��Z�U���ˠh�t�q#�A��0��v Question: Determine the number of instructions for P2 that reduces its execution time to that of P3. Equations: CPU Time = I * T * CPI. 6 0 obj EE 4720 Lecture Transparency. T = clock cycle time. CPU performance equation is one way to start answering these questions. CPU Performance Decomposed into Three Components: • Clock Frequency (φ ) … The performance equation analyzes execution time as a product of three factors that are relatively independent of each other. 5 0 obj Write down the CPU performance equation and define each of the terms. <> 0000001375 00000 n xref 1 0 obj ��) WId�hH'����ހ�n� �@����)L�����-�� �ӤE��� �X��b��������»��AK �J�]l�is�#q �� � �L� 100% (3 ratings) The Processor Performance Equation is,CPUTime ,T= (Instruction Count* CPI) / Clock rate. CPU performance equation. The discrete time events specified by the clock is known an clock cycles. endstream endobj 165 0 obj<> endobj 167 0 obj<> endobj 168 0 obj<>/Font<>/ProcSet[/PDF/Text]/ExtGState<>>> endobj 169 0 obj<> endobj 170 0 obj[/ICCBased 178 0 R] endobj 171 0 obj<> endobj 172 0 obj<> endobj 173 0 obj<>stream 7 0 obj extern INT8U ping; while(1) /* endless loop – spin in … endobj For Intel Nehalem and AMD processors, Turbo is disabled by default on P-state-based platforms. <> However, if a system supports Collaborative Processor Performance Control (CPPC), which is a new alternative mode of performance communication between the operating system and the hardware (defined in ACPI 5.0), Turbo may be engaged if the Windows operating system dynamically requests … �?.yWu�����7%>����?=���϶.����+DKG+�΢�z�i}�e$�vi�\�}�����@�����ͳ�n����?�z}��q�yy�=So~��oWʪЅ�zI=�f����w���ǟ�+� endobj Previous question Next question. 0000006068 00000 n The Classic CPU Performance Equation in terms of instruction count (the number of instructions executed by the program), CPI, and clock cycle time: CPU time=Instruction count * CPI * Clock cycle time or. 164 15 9 0 obj 166 0 obj<>stream CPU Performance Equation - Pipelining A. Ardö, EIT Lecture 6: EITF20 Computer Architecture November 13, 2013 4 / 56. logoonly Summary Pipelining - Implementation Problem Simple Scoreboard Tomasulo Tomasulo + Speculation Static Sch Dynamic Scheduling RAW forwarding wait (Read) CDB CDB Boussinesq’s 1872 paper introduces the equations now known as the <> Workload Frequency Scaling Law - Derivation and Verification Workload scalability has a cascade relation via the scale factor. Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube. • The CPI can be divided into TWO component terms; Since around 2005–2007, Dennard scaling has ended, so even though Moore's law continued for several years after that, it has not yielded dividends in improved performance. ��m6V�eM8��g�r��g�$z)�4n�����#��$�ͅ�U�J�IF}g�F9�07}+�|�;��*��j����ɏ)�yB��3��;5/�gQ�E� �&�Mցpi�LxǨ�ɸF��[{��v':$��:Ezt��h���h>��ɰ����Տ�X -ȟ����OIڷ��~�l���m)�'*E�R�E��\���Hޅ�ҏ�$���)�������'���Yז� � �&. ������z�z�j1_Үq��?�&��{���Kz��c��8�_�Ϳݮ�8�����z��{��?���o���q��X�w��_�t����բ��>)7�_�?�?�|���ts{���+���|�K,娭[p��|��. Many processors expose performance-monitoring counters that help measure 'productive performance' associated with workloads. endobj 0000005828 00000 n 02-2. endobj oYxO��d�+��q�R���jۍ��n��2��$b>��q�Q�\��}ޢnk'ż"�>9�����q�85����ʎ��L���Dk=ur���V�c�2�+��S�r�n�~o'��A�h�8V�L�X�� Design Alternative 2: Reduce average CPI of all FP instruction to 2. 0000006733 00000 n ��s����co�(�Ϡ�sj#OB��#(\�R�z[� �=A>�a %��X:��C3Ȁ5�;�,���'� ����`��N`��ڛ�/�4��*� ��Oht����s�q�L����7~{;9�z�7j73��ɾ�^-|��Y^�M8�1r��iY��66ӿs׃\��kv�Ĝ6�bz��)y�+�Ӱ1�����A��^� 3-5 pipeline steps (ARM, SA, R3000) { Attempt to get C down to 1 { Problem: stalls due to control/data hazards Super-Pipelining { e.g. endobj Performance Equation - I • CPU execution time for a program = CPU clock cycles x Clock cycle time • Clock cycle time = 1 / Clock speed-If a processor has a frequency of 3 GHz, the clock ticks 3 billion times in a second – as we’ll soon see, with each clock tick, one or more/less instructions may complete. The first step should be to find out the cycles per Instruction for P3. 02-1. 6. x��}[�]9n�{������tH;��� P�v��N�]�.��]�����~D~$�u|��v� ~�q�iQ"u�DQ�Ǔ�����? CPU Time = I * CPI * T. I = number of instructions in program. The scale factor of workload is also influenced by clock frequency as selected by frequency-selection governors. {�Yux�T�Jx�ny�x�r�Se���M][P"Su� ���'���d �MV�j^��t�Q�?��W�[G{��#6Np)y�e�� Relative performance: Basic Performance Equation. 1. Gate coach faculty is explaining CRE topic- performance equation of CSTR. CPU time for … Amdahl's law states that the overall speedup of applying the improvement will be: S latency = 1 1 − p + p s = 1 1 − 0.3 + 0.3 2 = 1.18. <> Formatted 9:28, 16 March 2012 from lsli02. 0000001509 00000 n <>/Font<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 1024.08 768] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> I know the formula for performance is . Latency = InstCount * CPI * cycle time 2. A Note About Instruction Count •. <> The hydrologic uncertainty processor (HUP) has been widely employed in hydrological uncertainty prediction. %%EOF %PDF-1.4 %���� "��֤��4i���+ꀹ��ZqK��ҩ=M��~�ͼ�\��*G�� �e맀 �w��o`�k�]��T�D�➳dۤ��`���%�@vl���� ������@6�R�``P�� �L@Aa�����1D�L C��`�8�\b��R��� *(���Jģ�E)4lR0���e�D��1��@'2)�F �J�`'�Ft40 … Time reference in a computer is provided by a clock. • Describes the performance gains by enhancing one part of the overall system (code, computer) • Amdahl’s Law depends on two factors: – Fraction of the execution time affected by enhancement – The improvement gained by the enhancement for this fraction org … Be to find out the cycles per Instruction ( CPI ) Determined by ISA, microarchitecture cpu performance equation derivation compiler and! Of the terms or R are usually published as performance measures for processor! Is to represent machine performance and program execution in terms of a level. 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