2. Objectives
define performance related terminology
define the need of benchmarks
define various factors of performance of
processor/memory/bus/storage
3. What is meant by
performance of a Computer?
The ability to execute instructions in accordance to the
specified configuration capabilities
4. Performance is measured for
Processor
The memory
The bus
Storage technologies, I/O devices &
The overall system
5. What is meant by a 32 bit Processor?
32 bit integer data may be processed at a time
The size of addresses may be 32 bits
232
= 4 Giga Byte Memory
Processor performance
terminology
7. Clock Speed
An internal clock regulates the rate of execution of
instructions and synchronizes various computer
components.
Clock speeds are expressed in Megahertz.
1 MHz = 1 Million clock cycles/second
8. A faster clock speed
faster computer?
YES
NO
One instruction/clock cycle
is possible in RISC
More than one instruction per
cycle is possible in Super scalar
Architectures
9. MIPS
A old measure of computer speed and power
Million instructions per second
Different instruction may require different times
No standard method for MIPS calculation
10. Does the MIPS stands for?
Meaningless Indicator of Performance.
It just provides the general idea of CPU capability
Pentium based system may run at 100 MIPS.
12. Super Computer needs to have
FPUs :
MFLOPS = 1 Million FLOPS
GFLOPS = 1 Million MFLOPS
13. 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
15. Access Time
The time taken to perform a Read or Write
Operation
The 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
17. Memory Cycle Time
Measures how quickly two back-to-back
accesses can be made
Access Time + Any additional time required
before a second access can commence.
18. Performance of the Bus
Bus Width: For example the width of PCI bus is 64
bits.
Clock speed: PCI have 33 or 66 or even 100 MHz
for some new configurations.
PCI may be implemented as 32 bit bus.
19. Performance of the Bus
Throughput: The amount of data transferred from
one place to another.
Typically, throughputs are measured in Kbps,
Mbps and Gbps
The PCI bus at 32 bits and 33 MHz, yields a
Throughput rate of 133 MBps
21. Access Time on Disks
Access Time on disks consists of:
Seek time: Time taken to position the head on the
required track
Rotational Latency: Time taken by a sector to
reach under the head while rotating.
23. Data Transfer Rate
The speed with which data can be transmitted
from one storage device through the interface
such as UDMA to system.
Data rates are often measured in Megabits or
Mega Bytes per second (Mbps or MBps).
Another term for data transfer rate is: throughput
24. Benchmark
A test used to compare performance of
hardware and/or Software
A benchmark may test graphics speed, year 2000
compliance of system or performance for integer
or floating point operations
25. SPEC
Standard Performance Evaluation
Corporation, a nonprofit corporation
set up by many computer and
microprocessor vendors to create a
standard set of benchmark tests.
Most The most widely used set of
tests SPEC95( CPU 95 test) measures:
Integer operations (SPECint95) and
Floating point operations (SPECfp95).
26. Sum Up
defined the performance factors for:
The CPU
The Memory
The Bus
The storage Devices
Defined the benchmark tests
