1. Hybrid Hard Drives with Non-Volatile Flash and Longhorn Jack Creasey Program Manager Hardware Innovation Group MSHybrid@Microsoft.com Microsoft Corporation

2. Demo Introduction Hybrid Hard Disk Architecture Power Savings using NV Cache Demo Results (Power saving) Faster Boot and Resume Process Demo (Boot and Resume) System Design with the Hybrid Hard Disk Other Design Approaches Next Steps Session Outline

3. Session Goals Attendees should leave this session with the following: An understanding of the power savings that can be achieved using Hybrid Hard Disk technology An understanding of the boot and resume efficiencies that can be achieved using Hybrid Hard Disk with Windows codenamed “Longhorn” An understanding of the increase in MTBF expected from a Hybrid Hard Disk Knowledge of where to find resources to aid in system design using the Hybrid Hard Disk

4. Storage Devices: Key Windows Strategies Optical Platform Client/Consumer Storage Fabrics Server/Enterprise Personal Storage Client/Consumer Preferred Storage Platform Partner/Customer Timely, comprehensive, quality platform support for optical devices Optimized platform features enabling new customer scenarios in Personal Storage Leading platform supporting storage fabrics Preferred platform for developing, integrating, and deploying storage devices

5. Demo Power Savings

6. Why Change the Disk Drive? Consumes 10-15% of the power budget in mobile solutions Slow power up Spin up times can be 2-5 seconds Seek and rotational latency is a performance bottleneck Fragile, shock prone, low MTBF in mobile systems Most common failure point in mobile solutions Failure may result in user data loss

7. What is a Hybrid Disk Drive? Dram Cache NV Cache Add a non-volatile cache ATA Interface

8. Why is a Hybrid Hard Disk Better? Reduce Power Consumption Read and Write disk data while drive is in a low power state with the spindle stopped Faster Boot and Resume Instant access to data in NV Cache Higher Reliability Better shock resistance Lower operating duty cycle

9. Hybrid Disk Drive Benefits Dram Cache NV Cache Up to 90% Power Saving when powered down ATA Interface Read and Write instantly while spindle stopped

10. Technical Assumptions for Hybrid Disk Longhorn* with its advanced memory management is the optimal for caching read data (but not write data) The Hybrid Hard Disk NV Cache is the optimal location for write data NV Cache should be >= 64MB and we recommend 128MB Longhorn* will be able to define data (LBAs) to be Pinned in the NV Cache for Boot and Resume benefits * Planned for Longhorn Beta 2

11. Flash Buffer Size for Power Reduction Field data from Windows XP-based PCs Preliminary results: >9,000,000 10min “active use” intervals 93% of 10min active use intervals < 64MB unique data written

12. Power Saving Mode Windows memory management buffers disk data in System DRAM which fulfills reads Windows puts the HDD into NV Cache mode which spins-down the disk spindle and results in write (and read) IOs to the NV Cache Upon NV cache miss or the NV Cache filling the spindle is spun-up to satisfy reads and flush write data to magnetic media The disk spins-down and continues to use the NV Cache 2.5” HDD Hard Disk Controller 64-128MB NV Cache Motherboard DRAM ATA Controller Windows Longhorn

13. Power Saving 80% reduction in power can be achieved (from 1.2W to 0.24W) Assumptions Pavg active = 1.2W (measured) Pavg with Flash write buffer and “Longhorn” kernel = 0.18W (calculated) Toff = 600s @.18W Ton = 15s @ 2.5W Ton = spin-up time (2s) + Flash buffer flush time (13s) Flash buffer size = 128MB Transfer rate = 10MB/s Pavg = ( 600*0.18 + 15*2.5 )/615 = 0.24W P o w e r ( W ) Time 1.5 1 0.5 Pavg with flash write buffer =.24W T off >600s on Pavg with disk spindle and seek in use = 1.2W T15s Power reduced0.76W

14. Demo Results View disk spindown times

15. Cold Boot Process BIOS runs POST Initializes the disk drive Reads partition table from disk Reads first logical block from bootable volume Reads NTLDR which executes and loads Windows

16. Hybrid Disk Boot and Resume During shutdown or hibernate all the disk sectors needed to boot or resume are pinned into the NV cache On next power on the BIOS POST runs and the disk is powered on but the spindle won’t be ready for 2-5 seconds BIOS can read data from the NV cache and all boot process IO can be satisfied immediately Once booted or resumed, Longhorn memory management fills system memory with most used disk data Windows puts the HDD into NV Cache mode which spins-down the disk and results in write and read IOs to the NV Cache Upon NV cache Read miss or the NV cache filling, the spindle is spun-up to satisfy Reads and flush cached write data to disk The disk spins-down and continues to use the NV cache 2.5” HDD Hard Disk Controller 64-128MB NV Cache Motherboard DRAM ATA Controller Windows Longhorn

17. Demo Suspend/resume

18. System Design with Hybrid Hard Disk Design objective: Enable fast boot/resume and save power Standard motherboard ATA Interface BIOS must exit POST rapidly Fast memory check Fast Chipset initialization Initialize HDD early BIOS must pass to boot loader quickly Fast PNP detection Boot HDD first in boot order Main memory => 512MB

19. Other Design Approaches Considered Flash memory device on the Motherboard Potential corruption if cache and disk separated Only provides partial functionality and requires significant additional design changes Requires new disk driver that owns pinning and cache management BIOS must be able to resolve cache/disk mapping before a driver loads Flash memory and Hybrid disk controller on Motherboard Potential corruption if controller and disk separated Double processes all commands to the disk subsystem Higher cost structure (additional ASIC)

20. HDD Partners Samsung Electronics – Semiconductor Division Flash product planning team worked with Microsoft on specification of the ATA command set Samsung Semiconductor, together with Seoul National University (SNU) developed the “proof of concept” prototype Hybrid Hard Drive emulator Samsung Electronics has started to develop commercial Hybrid Hard Disk drives Hitachi Worked with Microsoft on specification of the ATA command set Provided feedback on Hybrid Hard Disk power, boot and MTBF models Seagate Worked with Microsoft on specification of the ATA command set

21. Community Resources Windows Hardware & Driver Central (WHDC) www.microsoft.com/whdc/default.mspx Technical Communities www.microsoft.com/communities/products/default.mspx Non-Microsoft Community Sites www.microsoft.com/communities/related/default.mspx Microsoft Public Newsgroups www.microsoft.com/communities/newsgroups Technical Chats and Webcasts www.microsoft.com/communities/chats/default.mspx www.microsoft.com/webcasts Microsoft Blogs www.microsoft.com/communities/blogs

22. Relevant Mobile Platforms Presentations TWDT05010 Building a Longhorn-Ready Mobile PC TWAR05001 Longhorn Power Management Update TWAR05002 System Performance Assessment Tools For Windows Longhorn

23. Call To Action HDD manufacturers should contact Microsoft for information on Hybrid Hard Disk support in Windows OS Implementation Whitepaper ATA Command Set OEMs Contact Hybrid Hard Disk Partners to plan OEM certification process OEMs need to include testing on Hybrid disk functionality at Longhorn Beta Two release Contact MSHybrid @ Microsoft.com with any questions.MSHybrid @ Microsoft.com