Close
  • Latest News
  • Artificial Intelligence
  • Video
  • Big Data and Analytics
  • Cloud
  • Networking
  • Cybersecurity
  • Applications
  • IT Management
  • Storage
  • Sponsored
  • Mobile
  • Small Business
  • Development
  • Database
  • Servers
  • Android
  • Apple
  • Innovation
  • Blogs
  • PC Hardware
  • Reviews
  • Search Engines
  • Virtualization
Read Down
Sign in
Close
Welcome!Log into your account
Forgot your password?
Read Down
Password recovery
Recover your password
Close
Search
Logo
Logo
  • Latest News
  • Artificial Intelligence
  • Video
  • Big Data and Analytics
  • Cloud
  • Networking
  • Cybersecurity
  • Applications
  • IT Management
  • Storage
  • Sponsored
  • Mobile
  • Small Business
  • Development
  • Database
  • Servers
  • Android
  • Apple
  • Innovation
  • Blogs
  • PC Hardware
  • Reviews
  • Search Engines
  • Virtualization
More
    Home Latest News
    • Networking

    IBM: Power5 Chip to Tap Threading

    Written by

    Mark Hachman
    Published August 19, 2003
    Share
    Facebook
    Twitter
    Linkedin

      eWEEK content and product recommendations are editorially independent. We may make money when you click on links to our partners. Learn More.

      PALO ALTO, Calif.—A clever implementation of simultaneous multithreading will allow IBM Corp.s Power5 processor to increase performance by 40 percent compared with the Power4, while only increasing the per-core die size by about 24 percent.

      Simultaneous multithreading, which Intel Corp. has marketed as “hyperthreading”, allows the processor to operate on whichever instruction stream, or “thread,” demands immediate attention.

      Since Armonk, N.Y.-based IBMs Power4 implemented two processor cores per chip, the Power5 will present four virtual cores to the operating system—two physical cores and two virtual ones—said Ron Kalla, a system designer for IBM, in a Wednesday presentation at the Hot Chips conference here.

      The Power5 chip is on track to ship in 2004, Kalla said. Initially, IBM will fabricate the chip using 130-nm process technologies, copper interconnects and silicon-on-insulator technology. In subsequent generations, IBM will shrink the die by manufacturing the chip on a 90-nm process, Kalla said.

      Kalla declined to offer hard details on the chips clock speed, cache sizes, cost, power, or other product-specific characteristics. Some of those details will be revealed at the Microprocessor Forum in October, according to Peter Glaskowsky, editor of The Microprocessor Report and an analyst at In-Stat/MDR, which is hosting the chip confab.

      Kalla characterized the Power5 as an extension to the Power4 architecture, with additions tacked on to support the additional thread. For example, a thread bit was added to most addressing buses to handle the additional thread. A second program counter was added after functions are called from the instruction cache, with a tag added to each instruction to indicate what tread the instruction belongs to as it is decoded, Kalla said.

      While the Power4 has 80 physical registers, 120 registers will be available to programmers using the Power5, Kalla said. All registers, caches and instruction units can be shared between both threads.

      The operating system can also assign up to eight thread priority levels to each thread, Kalla said. If both threads are idle—Priority 0—the operating systems can turn the processor off to consume power, he said. Most of the microarchitectural units within the chip are power-managed, although Kalla declined to say what the effect the power management would have.

      But actually disabling the multithreading option actually has an important side effect—it can improve performance, Kalla said. Turning off a thread gives the single thread access to all 120 registers, affording the Power5 a significant instruction-per-clock (IPC) advantage compared with the Power4. IBM architected the Power5 to allow the operating system to turn the Power5s SMT capabilities on and off to maximize performance, Kalla said.

      According to Kalla, IBM has booted the chip in its labs on the AIX, Linux and OS/400 operating systems.

      Mark Hachman
      Mark Hachman

      Get the Free Newsletter!

      Subscribe to Daily Tech Insider for top news, trends & analysis

      Get the Free Newsletter!

      Subscribe to Daily Tech Insider for top news, trends & analysis

      MOST POPULAR ARTICLES

      Artificial Intelligence

      9 Best AI 3D Generators You Need...

      Sam Rinko - June 25, 2024 0
      AI 3D Generators are powerful tools for many different industries. Discover the best AI 3D Generators, and learn which is best for your specific use case.
      Read more
      Cloud

      RingCentral Expands Its Collaboration Platform

      Zeus Kerravala - November 22, 2023 0
      RingCentral adds AI-enabled contact center and hybrid event products to its suite of collaboration services.
      Read more
      Artificial Intelligence

      8 Best AI Data Analytics Software &...

      Aminu Abdullahi - January 18, 2024 0
      Learn the top AI data analytics software to use. Compare AI data analytics solutions & features to make the best choice for your business.
      Read more
      Latest News

      Zeus Kerravala on Networking: Multicloud, 5G, and...

      James Maguire - December 16, 2022 0
      I spoke with Zeus Kerravala, industry analyst at ZK Research, about the rapid changes in enterprise networking, as tech advances and digital transformation prompt...
      Read more
      Video

      Datadog President Amit Agarwal on Trends in...

      James Maguire - November 11, 2022 0
      I spoke with Amit Agarwal, President of Datadog, about infrastructure observability, from current trends to key challenges to the future of this rapidly growing...
      Read more
      Logo

      eWeek has the latest technology news and analysis, buying guides, and product reviews for IT professionals and technology buyers. The site’s focus is on innovative solutions and covering in-depth technical content. eWeek stays on the cutting edge of technology news and IT trends through interviews and expert analysis. Gain insight from top innovators and thought leaders in the fields of IT, business, enterprise software, startups, and more.

      Facebook
      Linkedin
      RSS
      Twitter
      Youtube

      Advertisers

      Advertise with TechnologyAdvice on eWeek and our other IT-focused platforms.

      Advertise with Us

      Menu

      • About eWeek
      • Subscribe to our Newsletter
      • Latest News

      Our Brands

      • Privacy Policy
      • Terms
      • About
      • Contact
      • Advertise
      • Sitemap
      • California – Do Not Sell My Information

      Property of TechnologyAdvice.
      © 2024 TechnologyAdvice. All Rights Reserved

      Advertiser Disclosure: Some of the products that appear on this site are from companies from which TechnologyAdvice receives compensation. This compensation may impact how and where products appear on this site including, for example, the order in which they appear. TechnologyAdvice does not include all companies or all types of products available in the marketplace.

      ×