Sun Starfire: Extending the SMP Envelope

1
Sun Starfire Extending the SMP Envelope

• Presented by Jen Miller
• 2/9/2004

2
Starfire Overview

• 24 64 processors
• Maximum of 4 processors per board
• Based on UMA, SMP snooping architecture
• Design focus on interconnect

3
System

• 250 MHz processors with 4 MB external caches
• 16 x 16 data crossbar
• Active centerplane
• Point to point routing
• 4 GB memory separated into 4 banks
• 4 way interleaved address bus

4
Interconnect

• Point to point routing centerplane transfers
  addresses and data between boards
• - Higher latency than traditional bus
• - Better bandwidth, reliability, availability
• 2 cycle address transactions
• - Bus determined by 2 low-order cache bits
• Data transactions
• - Waiting packets are buffered and sent in 8
  cycles buffer-to-buffer

5
Dynamic System Domains

• Can be dynamically subdivided into multiple
  computers
• Each domain is a separate shared-memory SMP
  system
• Errors confined to domain
• Great for testing and development
• Starfire can replace multiple smaller systems
• Domains can be created for special functions
• Implemented in centerplane and system boards via
  registers

6
Reliability

• ECC for data transfers and address packets
• Optional hardware redundancy
• Auto-reboot crash recovery

7
Performance

• Bandwidth increased dramatically over prior
  generations
• Unix server flexibility with Dynamic System
  Domains
• Reliable, available, and serviceable
• Can match or exceed performance of other
  parallel architectures for a lower system cost