1. Indira Gandhi National Open University presents

2. A Video Lecture Course: Computer Platforms

3. Performance of A Computer System

4. Objectives cdefine performance related terminology cdefine the need of benchmarks cdefine various factors of performance of processor/memory/bus/storage

5. What is meant by performance of a Computer? cThe ability to execute instructions in accordance to the specified configuration capabilities

6. Performance is measured for cProcessor cThe memory cThe bus cStorage technologies, I/O devices & cThe overall system

7. cWhat is meant by a 32 bit Processor? l 32 bit integer data may be processed at a time l The size of addresses may be 32 bits 2 32 = 4 Giga Byte Memory Processor performance terminology

8. Processor performance terminology cClock speed cMIPS cFLOPS

9. Clock Speed Clock Speed cAn internal clock regulates the rate of execution of instructions and synchronizes various computer components. cClock speeds are expressed in Megahertz. 1 MHz = 1 Million clock cycles/second

10. A faster clock speed  faster computer? cYES cNO One instruction/clock cycle is possible in RISC More than one instruction per cycle is possible in Super scalar Architectures

11. MIPS cA old measure of computer speed and power cMillion instructions per second cDifferent instruction may require different times cNo standard method for MIPS calculation

12. Does the MIPS stands for? cMeaningless Indicator of Performance. cIt just provides the general idea of CPU capability cPentium based system may run at 100 MIPS.

13. FLOPS cFloating-point operations/second. cMeasures the speed of floating point unit (FPU).

14. Super Computer needs to have FPUs : MFLOPS = 1 Million FLOPS GFLOPS = 1 Million MFLOPS

15. Which is the most frequently used transfer for Instruction execution? The Processor to Memory or vice versa Therefore, for better performance, the CPU need better memory capabilities

16. Performance terms for Main Memory cAccess Time cCycle Time

17. Access Time cThe time taken to perform a Read or Write Operation cThe time from the instant that an address is presented to the memory to the instant the data have been stored or made available for use

18. Typical Access Time 55-250 nanoseconds read-only memory (ROM) 55-250 nanoseconds EPROM 50-70 nanosecondsdynamic RAM (DRAM) 5-15 nanosecondsstatic RAM (SRAM)

19. Memory Cycle Time cMeasures how quickly two back- to-back accesses can be made cAccess Time + Any additional time required before a second access can commence.

20. Performance of the Bus cBus Width: For example the width of PCI bus is 64 bits. cClock speed: PCI have 33 or 66 or even 100 MHz for some new configurations. cPCI may be implemented as 32 bit bus.

21. Performance of the Bus cThroughput: The amount of data transferred from one place to another. cTypically, throughputs are measured in Kbps, Mbps and Gbps c The PCI bus at 32 bits and 33 MHz, yields a Throughput rate of 133 MBps

22. Performance factors for Storage technologies cAccess time cData Transfer rate

23. Access Time on Disks Access Time on disks consists of: cSeek time: Time taken to position the head on the required track cRotational Latency: Time taken by a sector to reach under the head while rotating.

24. Access Time 80-800 milliseconds CD-ROM 19-100 milliseconds Erasable Optical 6-12 millisecondsHard Disk Drive

25. Data Transfer Rate cThe speed with which data can be transmitted from one storage device through the interface such as UDMA to system. cData rates are often measured in Megabits or Mega Bytes per second (Mbps or MBps). cAnother term for data transfer rate is: throughput

26. Benchmark cA test used to compare performance of hardware and/or Software cA benchmark may test graphics speed, year 2000 compliance of system or performance for integer or floating point operations

27. SPEC cStandard Performance Evaluation Corporation, a nonprofit corporation set up by many computer and microprocessor vendors to create a standard set of benchmark tests. cMost The most widely used set of tests SPEC95( CPU 95 test) measures: l Integer operations (SPECint95) and l Floating point operations (SPECfp95).

28. Sum Up cdefined the performance factors for: l The CPU l The Memory l The Bus l The storage Devices cDefined the benchmark tests