Next Mobile Storage Solution - Evolution from eMMC to UFS -
Mobile Memory Forum CES 2012
Hangu Sohn
Samsung Electronics Co. LTD
Unit : M Set
Smartphones overtake PCs in 2011
Source: Samsung Marketing, 3Q11
2X
● We’re going ‘Mobile!’
• From ‘11, Smart-phones overtake PC Shipments and Tablets will add to the gap significantly
● What is Driving High Performance in Mobile…
• High Computing Power(DC/QC* CPU) & High Storage Capacity (>64GB)
• Low Latency and High IOPS (Random) & Bandwidth (Sequential)
Video editing/ 3D Games
Fluid Responsiveness
Seamless Web Surfing/Social Networking
DC/QC: Dual Core, Quad Core
● What is UFS (Universal Flash Storage)?
• Low Power of eMMC + High Performance of SCSI SSD
• Two form factors: 1) Embedded SSD 2) SD card form factor
SCSI
SSD
e-MMC
UFS
● UFS: Less pins by/in Serial and Multiple Lanes
• Two types of speed modes and a ‘Minute Power’ state for low power
eMMC: Limitation of Parallel Interface
Parallel data pins
Pe
rfo
rman
ce
•More parallels higher power
•More pins Cost Up
•Signal Skewing •Crosstalk
Optional expansion
UFS: MIPI M-PHY for higher speed
M-TX
M-RX
M-TX
M-RX
M-RX
M-TX
M-RX
M-TX
UFS: Two types of Speed modes and Multiple Gears UFS: Power State Diagram
● UFS: Utilizes and extends eMMC functionality
UFS e-MMC 4.5
Security Trim/Discard Yes
Sanitize Yes
RPMB Yes
Data Integrity Write Protect Yes
Partitioning Yes
Performance
enhancement
Cached opt Yes
Data-Tag Yes
Context-ID Yes
Packed CMD CMD queuing
Flash
Management
Background opt Yes
Real time Clock Yes
Partition types Yes
Protocol
enhancement
Synch Asynch
State transition Stateless
● UFS: Optimized for Multi-threaded Applications • Full utilization of multiple NAND operations
- UFS: Heterogeneous commands can be executed in parallel vs. SATA: Parallel execution, but limited by SATA protocol
<Key Assumptions: Write takes 3x longer than read. Write-through mode. No storage cache available>
Time
Thread A
Thread B
Thread D
Thread C
Wo
rk L
oa
d
Time
UFS
SATA
W
W
R R R R
W
R
R R
#1
#2
#3
#4
NAND
R W
W
W
R
R
W
W
R R R R R
R R R
W
W
W #1
#2
#3
#4
NAND
W
W
R
R R R R R
R R
R
R
R
R
R
Tx
Rx
Tx
Rx
R
Host I/F
Host I/F
Waiting for completion of write
Long idle (Write delayed)
Simultaneous Tx/Rx possible
Barrier
Normalized Throughput UFS vs .SSD
QuadRant_IO x1.79
RL_Bench x1.94
Web Browsing
x2.49
● UFS: Time-critical Applications • Worst UX: Request delay due to Storage Write Busy • Better User Experience: High Priority LU for time-critical application
Time
Suspended Suspended Suspended
UFS
SATA
Partition 0 (High Priority LU)
Partition 1
Single Partition
App Download App Install
App Download
App Download
App Install
Video Playing
Video Playing
App Install
Delayed Start Delayed Completion Failed to meet deadline
Camera Shooting Events Video Playing
Camera Shooting
Camera Shooting
Video Playing
Video Playing
App Install
Code execution
Code execution
Code execution
eMMC4.5 (HPI)
Long write
Media data read request
Media data read Pending over 100ms
Write Issue Write Completion
● UFS: High Bandwidth & High IOPS
• Sequential Performance: Separate R/W channel + Scalability by/through Multiple Lanes (x1/x2/x4) and Gears (3.0Gbps, 6.0Gbps)
• Random Performance: Asynchronous Protocol (Command Queuing)
2010 2011 2012 2013 2014
eMMC
SATA
2015
SD
HSIC (USB2)
Th
rou
gh
put M
bit/s
ec
Dual Lane
Single Lane
2010 2011 2012 2013 2014
SD
eMMC
SATA
2015 HSIC (USB2)
Read IO
PS
UFSA Estimates
UFSA : UFS Assoiaction
Sequential Performance
Random Performance
M-PHY : Mobile PHY has been defined by MIPI (Mobile Industry Processor Interface)
Re
lative
Id
le P
ow
er
● UFS: Optimizes Power to target Mobile applications
• UFS provides Lower Standby Power by adopting M-PHY
• Key point for ‘Always-On’
UFSA Estimates
SD eMMC UFS HSIC SATA
SATA Slumber
SATA DEVSLP
2011 2012
UFS 1.0 Editorial
MIPI M-PHY1.0
MIPI Unipro 1.4
HCI 1.0
Device
Chipset
● Industry moving to UFS…
• SPEC completed in ’11, not only for Devices but also HCI
• Coming up: Device & Host Chipset in ‘12
HCI: Host Controller Interface
Application
I/O Manager
File System
Storage Class Driver
UFS Device Driver
UFS HCI
Host Controller UFS Device
Compliant with e-MMC4.5 feature
Working on adoption
Compliant with SCSI & e-MMC
Compliant with SCSI
New Software driver
but Standard HCI &Device drivers S/W
H/W
● UFS provides easy Software adoption by e-MMC 4.5 features and SCSI compliance…
• UFS Device Driver & UFS HCI by Standard HCI & Device drivers
JC 64.5 UFSA ATC
Test procedure
& spec
UFS compliance
specification
Certification
● JEDEC has moved for setting up UFS Test Infra …
• JC64.5 for UFS test procedure & test spec
• Compliance/Certification will be available from UFSA soon
● UFS is Ready…Successfully demonstrated and converging with Portable Computing Devices
UFS Demo based on FPGA Level (by Samsung 4Q’11)
THANK YOU