Windows Vista Performance Technologies.ppt

Windows Vista Performance Technologies System Responsiveness Ensuring Memory is well Utilized SuperFetch Avoiding the Disk Bottleneck ReadyDrive Hybrid Hard Drive ReadyBoost Expanded Memory Devices Supporting infrastructure Low-priority I/O Diagnostic tools What Causes Inconsistent System Responsiveness? Poor Memory Content Performance erodes over time The application has not run recently Background applications have swept through memory Transition-related After boot or hibernate After Fast User Switch After lunch or big application Random/Blocking Disk Operations Page faults Program loads Disk spin up time Poor Memory Contents Effective management of a limited shared resource under contention A perennial computer science problem Affects Disk, CPU, Network, etc. Typical Memory Pressure Scenario Memory is populated with pages for Application A Application B is loaded, pushing App A’s pages out User switches back to Application A Application A reloads pages as needed through Pagefaults, pushing out Application B’s pages Repeat cycle… The Seek Problem Drive Industry Continues to Deliver Impressive Data Rate, Rotation and Interface Speed Improvements ATA/33 ? ATA/66 ? ATA/100 ? SATA 4200RPM ? 5400RPM ? 7200RPM ? 10000RPM 2 MB ? 8 MB ? 16 MB Result: Sequential IO rates of 80 MB/s+ At that rate, 1 GB of RAM fully populated in ~12.8sec Seek Times Improving, but not as Significantly 3.5” Desktop drive avg seek ~10 mSec 2.5” Mobile drives ~12.5 mSec Much better when hitting the track buffer… Result: Random IO rate limited to an effective 1MB/sec At that rate, populating 1GB of RAM takes ~1024sec! The Seek Problem 50% of MobileMark 2005 I/Os are 4 KB and Random Files and Structured Files A single DLL is generally 5 to 6 Disk Locations (min) Directory, MFT Entry, and other File System Metadata PE Hdr page, .text pages, .data pages, .rsrc pages,… Programs like Internet Explorer, Adobe Reader, or Outlook use over 100 DLLs Reliability and Durability Logging, Transaction