Optimizing Test with Multiprocessor Machines

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Optimizing Test with Multiprocessor Machines

• Eric Starkloff
• Software Marketing Manager
• Fri Aug 18
• 1015-1130 a.m., 145-300 p.m.
• Cedar (8C)

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Why Use Multiprocessor Computers?

• Keep time-critical tasks from being greatly
  affected by User Interface (UI)
• Keep UI responsive while performing task in
  background
• Data acquisition and storage on one processor
  with UI on the other
• Increase overall performance of application
• Increase development speed
• Run more applications without degrading
  performance
• Faster compiling for large applications

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SMP (Symmetric Multiprocessor)

• The most common multiprocessor configuration
• Each processor shares common memory, disk, and
  I/O
• Each processor has its own cache

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Multiprocessor Availability

• Increasingly common to see dual- and quad-
  processor workstations and desktops
• Prices on multiprocessor machines continue to
  drop
• Can your application benefit enough from a
  multiprocessor machine to justify its cost?

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Multiprocessor Examples

• Dell precision workstations
• Available in dual-processor Pentium III and
  Pentium III Xeon
• Start at 3559
• Compaq AP workstations
• Available in dual-processor Pentium III and
  Pentium III Xeon
• Start at 4400
• Sun
• Ultra workstations available in dual- and quad-
  processor configurations
• Start at 11,000
• Apple
• Dual-processor PowerMacs rumored for 2001

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Operating System Support

• Windows NT 4.0/2000
• NT Workstation/Win 2000 Pro. 2 processors
• NT/Win 2000 server - 4 processors
• Win 2000 advanced server 8 processors
• Win 2000 Datacenter server 32 processors
• Unix
• Linux
• With 2.2 kernel
• Mac OS
• Will have some multiprocessor support in OS X

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Multithreading Terms

• Multitasking
• Multiple executables running concurrently
• Preemptive vs. non-preemptive
• Multithreading
• Multiple threads in a single executable

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Multitasking
Word processor
FTP client
T I M E
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Multithreading
Word processor
T I M E
Process UI
Printing
Thread 1
Thread 2
Program
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Processor Affinities

• Determine which processor a thread will run on

• Can be set for a process manually, in the task
  manger
• Or programmatically, for a thread or process
  through windows API

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Creating a Multiprocessor Test Application

• Use any application capable of creating and
  managing multithreaded applications
• TestStand
• LabVIEW (5.0 or later)
• LabWindows/CVI (5.5 or later)
• Visual C
• Visual Basic
• Understand how to synchronize threads and protect
  data

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Calculating Multiprocessor Performance
Improvements

• Amdahls Law
• Performance
• improvement
• T execution time
• f of time that application runs in parallel
  on P processors
• P number of processors
• Example
• 75 of application can be run in parallel yields
  a 1.6X performance improvement

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Dual Processor Benchmarks
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Other Sources of Information

• Intel multiprocessor benchmarks and cost
  justification calculator
• intel.com
• LabVIEW multithreading and synchronization
• LabVIEW multithreading on Developer Zone
  (zone.ni.com)
• LabWindows/CVI multithreading and synchronization
• Building Multithreaded Applications with
  LabWindows/CVI in Developer Zone
• TestStand Multithreading and synchronization
• Creating Multi-head Test Systems session
• Application note 136 Using Multithreading to
  Increase Test System Throughput

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Questions?