Windows Vista: System Performance Enhancements Simon Martyn Infrastructure Specialist The IQ...
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Transcript of Windows Vista: System Performance Enhancements Simon Martyn Infrastructure Specialist The IQ...
Windows Vista: Windows Vista: System Performance System Performance
EnhancementsEnhancements
Simon Martyn
Infrastructure Specialist
The IQ Business Group Technology Services Division
Agenda• Current performance limitations• Optimizing Memory Use
– SuperFetch™• Avoiding the Disk Bottleneck
– ReadyBoost™– ReadyDrive™
• Supporting infrastructure– Low-priority I/O– Diagnostic tools
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
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!
.data pages.data pages
MFT EntryMFT Entry
Directory EntryDirectory Entry
PE HeaderPE Header.text pages.text pages
DramDramCacheCache
DLLs On DiskDLLs On Disk
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 be
faulted upon– Hard to develop Asynchronous Client applications
What Do Users See?
• Slow state transitions• Decreased application responsiveness under memory
pressure• Slower program launch
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
Smart Memory Management
Internet ExplorerInternet Explorer
MemoryMemory
OS
Startup Apps
Microsoft Word
Outlook
Photo Editor
DiskDisk
free memoryfree memory
memory cachememory cache
Current Memory Management
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
Internet Explorer
MemoryMemory
OS
Startup Apps
Microsoft Word
Outlook
Photo Editor
DiskDisk
memory cachememory cache
Photo Editor
SuperFetch
SuperFetch
• SuperFetch is proactive and resilient– Smart about getting the right content into
memory early– Keeps correct content in memory
Internet ExplorerInternet ExplorerIdle Tasks
Microsoft Word
OutlookIdle Tasks
Internet Explorer
Idle TasksOutlook
Idle Tasks
MS WordIdle Tasks
OS
Startup Apps
PhotoshopPhotoshop
Traditional
OS
Startup Apps
Photoshop
memorycache
OS
Startup Apps
PhotoshopPhotoshop
Superfetch
OS
Startup Apps
Photoshop
Keeping The Right Data In Memory
SuperFetch
• SuperFetch is efficient– Uses low priority I/O for pre-fetching
and pre-population• SuperFetch manages RAM and
cache memory
Avoid The Disk Bottleneck
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
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
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
DramCache
NVCache
Up to 90% Power Saving
over conventional HDD
SATA or PATA Interface
Read and Write while spindle is stopped
MFT EntryMFT Entry
Directory EntryDirectory Entry
DramDramCacheCache
.data pages.data pages PE HeaderPE Header.text pages.text pages
DLLs On DiskDLLs On Disk
MFT Entry
Directory Entry
PE Header
.text pages
DramCache
NV Cache
.data pages
DLLs On ReadyDrive H-HDD
NV Cache contents
• Cached writes• Boot/resume sectors• Sectors pinned by OEMs• Read cache
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 with
NV memory• Reduced noise
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
ReadyBoost And ReadyDrive
System Memory
HDD Platter
Read Cache
ReadyBoost
Write Cache
OEM Pinning
Boot Data
Read Cache
ReadyDrive
NVRAM
RAM
Magnetic
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
Prioritized I/O
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
Using Low-priority I/O
• Call SetThreadPriority with THREAD_BACKGROUND_MODE_BEGIN
• Call SetProcessPriorityClass with PROCESS_BACKGROUND_MODE_BEGIN
Diagnostic Tools
Current Tool Limitations
• Repeatability – Often times, issues are non-deterministic
• Proactivity– Event logs are a good start but not
end-user friendly
PerformanceAnalyzerWindows
DiagnosticInfrastructure
System Event Log
CKCL - ETW Kernel Events
Performance Diagnostics Architecture
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
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)
Thank you to our Partners for their support of TechDays
2007