Windows Vista: System Performance Enhancements

1. Windows Vista: System Performance Enhancements Simon Martyn Infrastructure Specialist The IQ Business Group Technology Services Division

2. Agenda • Current performance limitations • Optimizing Memory Use • SuperFetch™ • Avoiding the Disk Bottleneck • ReadyBoost™ • ReadyDrive™ • Supporting infrastructure • Low-priority I/O • Diagnostic tools

3. What Causes Inconsistent Responsiveness? • Poor memory content • Performance erodes over time • The application has not run recently • Background applications have swept through memory • Transitions affect memory • 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 • Disk seeks

4. 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!

5. DLLs On Disk .data pages .text pages PE Header Dram Cache MFT Entry Directory Entry

6. 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, etc. Programs like Internet Explorer, Adobe Reader, or Outlook use over 100 DLLs Reliability and durability Logging, Transactions, Application Temp Files A simple Registry Write can require 5 to 6 Random and Ordered Disk Writes Synchronous blocking nature of page faults Code pages, Stack pages, and Heap pages can all befaulted upon Hard to develop Asynchronous Client applications

7. What Do Users See? Slow state transitions Decreased application responsiveness under memory pressure Slower program launch

8. How Does Microsoft Windows Vista Help? Provides new innovations inmemory management Avoids hitting the disk where possible Prioritizes I/O when you do hit the disk Contains new diagnostic tools

9. SmartMemory Management

10. Current Memory Management Memory Photo Editor Internet Explorer Internet Explorer memory cache Outlook free memory Disk Microsoft Word Startup Apps OS

11. SuperFetch SuperFetch is a breakthrough inmemory management Optimizes based on usage patterns over time Takes into account frequency of page usage, usage of page in context of other pagesin memory Adapts to memory usage patterns, including complex usage scenarios Can differentiate based on user, time and day of week

12. SuperFetch Memory Photo Editor Photo Editor Internet Explorer Outlook memory cache Microsoft Word Disk Startup Apps OS

13. SuperFetch SuperFetch is proactive and resilient Smart about getting the right content into memory early Keeps correct content in memory

14. Keeping The Right Data In Memory Traditional Superfetch Photoshop Photoshop Photoshop Photoshop Photoshop Photoshop Idle Tasks Internet Explorer Internet Explorer Idle Tasks Idle Tasks Internet Explorer Outlook Outlook Idle Tasks memory cache Microsoft Word Idle Tasks MS Word Startup Apps Startup Apps Startup Apps Startup Apps OS OS OS OS

15. SuperFetch SuperFetch is efficient Uses low priority I/O for pre-fetching and pre-population SuperFetch manages RAM andcache memory

16. Avoid The Disk Bottleneck

17. ReadyBoost • Flash memory serves as a cache for SuperFetch • External USB keys, SD cards, Compact Flash, internal PCIe cards • Allows fast reads to satisfy page faults when page is not in main memory • Up to 10x faster than random HDD reads • Caches data proactively based onuser activity

18. ReadyBoost Properties Reliable Write-through cache allows user to remove deviceat any time Device wear is not an issue Unique write gathering algorithm optimizes performance and wear patterns Projected life of 19.4 – 1823 years depending on device size and variant (10K or 100K write-erase cycles) Secure Data is encrypted using AES-128 Efficient Data is compressed by a factor of 1.8X to 2.3X

19. ReadyDrive Hybrid Hard Disk A Nonvolatile cache (NV Cache) is added to the hard disk drive Allows data to be read and written while platter is spun down Data in cache persisted when powered down SuperFetch provides efficient cache utilization Up to 90% Power Saving over conventional HDD Read and Write while spindle is stopped Dram Cache SATA or PATA Interface NV Cache

20. DLLs On Disk .data pages .text pages PE Header Dram Cache MFT Entry Directory Entry

21. DLLs On ReadyDrive H-HDD .data pages .text pages PE Header Dram Cache NV Cache Directory Entry MFT Entry

22. NV Cache contents Cached writes Boot/resume sectors Sectors pinned by OEMs Read cache

23. ReadyDrive Benefits Performance Faster Boot Faster Hibernate/Resume Performance improvement from minimizing disk seeks and enabling more IOs per second Power Savings/Battery Life Windows Vista can reduce HDD power consumption of typical 2.5” HDD by 70-90% when operating on battery by keeping magnetic platter spun down most of the time Reliability improvements Vibration or impact during writes not a problem withNV memory Reduced noise

24. ReadyDrive ATA Command Set A new ATA command set has been specified by Microsoft, HDD manufacturers, and industry partners which enables rich management of the NV Cache Single ATA command with sub-commands Identify hybrid hard disk functionality Add/Remove LBAs from NV Cache “pinned set” Query NV Cache pinned set Enter/Leave power saving mode Etc. Accepted by T13 for standardization in the ATA 8 specification Opportunity for innovation by device and host moving forward

25. ReadyBoost And ReadyDrive Boot Data Read Cache Write Cache OEM Pinning System Memory RAM ReadyBoost Read Cache NVRAM ReadyDrive HDD Platter Magnetic

26. ReadyBoost And ReadyDrive ReadyBoost and ReadyDrive arecomplementary technologies Both powered by SuperFetch ReadyDrive Helps state transitions Can pin and accelerate some data Improves reliability Saves power ReadyBoost Large read cache Relieves memory pressure

27. Prioritized I/O

28. Low-priority I/O Why low-priority I/O? Developers have long been able to throttle CPU usage by setting thread priorities Low CPU usage can still slow down the system With Windows Vista, developers can set I/O priorities Low-priority I/O applications SuperFetch Search indexing Windows Defender Disk defrag software Startup applications

29. Using Low-priority I/O Call SetThreadPriority with THREAD_BACKGROUND_MODE_BEGIN Call SetProcessPriorityClass with PROCESS_BACKGROUND_MODE_BEGIN

30. Diagnostic Tools

31. Current Tool Limitations Repeatability Often times, issues are non-deterministic Proactivity Event logs are a good start but notend-user friendly

32. Performance Tuning And Diagnostics Lower the cost for diagnosing performance problems Easier diagnosis and resolution of performance problems Leverages data within the Circular Kernel Context Logger (CKCL) Provides a record of recent system activity Automated analysis applied for defined scenarios Analysis results written to System Event Log Performance Diagnostics Architecture Performance Analyzer CKCL - ETW Kernel Events Windows Diagnostic Infrastructure System Event Log

33. Vista Performance Benefits Windows Vista Delivers Consistent Performance Improved power transitions Consistent responsiveness, even in adverse conditions Windows Vista uses innovative technology to address the biggest user issues SuperFetch is a breakthrough in memory management ReadyDrive Hybrid Hard Disks provide reliability, battery, and performance benefits ReadyBoost enabled flash improves responsiveness without needing to add more RAM Low priority I/O prevents background applications from affecting user actions Windows Vista has improved diagnostic infrastructure Circular Kernel Context Logger (CKCL)

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