Host Memory Buffer (HMB)based SSD SystemForum J-31: PCIe/NVMe Storage

Jeroen Dorgelo

Mike Chaowei Chen

Agenda

• Market Trends in Client SSD

• Introducing DRAMless architecture for SATA & PCIe

• Host Memory Buffer(HMB) scales up DRAMless PCIe SSD

• HMB DRAMless vs. DRAM-based SSD

• Ecosystem development

13-Aug-15Flash Memory Summit 2015 2

Market Trends

• Main drivers for SSD adoption have been:

– Performance

• PC Mark8 score from HDD to SSD: 1,200 to 4,800 points (SATA)

• Latest PCIe Gen3x4 NVMe drives score over 5,100 points

– Form Factor:

• Ultrabooks require space to fit in battery

• SSD can shrink to module size (M.2)

• BUT all came with a Premium to pay

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170 167 165

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256GB 128GB HDD

• Now: cost parity of 128GB SSD and 500GB Mobile HDD

Market Trends

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145139

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9582

76

103 102 99 9787

7565

5950 46 41 3843 41 40 40 40 40 39 39 39 38 38 38

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Time

Developing DRAMless architecture

DDR3

4GB

CPU

Southbridge

128GB SSD Mainstream Entry Level

NAND CH 4 2

NAND speed 333MT/s 400MT/s

Capacity 64Gb MLC

16dies

128Gb TLC 8dies

Memory 16bit DRAM I/F DRAMless

• 2015 SSD Architecture: Mainstream vs Entry-level

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Mainstream SSD

SATA

DDR3

PC

NANDNAND

NANDNAND

NANDNAND

NANDNAND

NANDNAND

NANDNAND

NANDNAND

NANDNAND

SSD SOC

CPUs

4CH NAND I/F

DRAM I/FSATA I/F

Memory 16bit DRAM I/F DRAMless

Entry-level SSD

NAND

SSD SOC

CPUs

2CH NAND I/F

NANDNAND

NAND

SATA I/F

NANDNAND

NANDNAND

SATA

What I can get from a $30ish SSD?

• 20X HDD performance in full testing range

• Or 100X HDD IOPS in small 4GB or 8GB range

• And 1/20 space with M.2 2230 or even smaller with BGA

– 1/10 in XY

– 1/2 in Z-height– 1/2 in Z-height

• And <2mW in Devslp mode

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Enabling Host Memory Buffer

• PCIe Gen3x1 NVMe SSD requests Host to allocate

Memory space

– In this case study: 128MB for the Look-up-Table

– But it can claim any custom size of Host DRAM (partial LUT)

• Same BOM cost as Entry Level SATA drive!

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– But it can claim any custom size of Host DRAM (partial LUT)

PCIe

Gen3x1

PC

DDR3

4GB

CPU

drawing not to scale

Southbridge

128GB SSD

NAND

SSD SOC

CPUs

2CH NAND I/F

NANDNAND

NAND

PCIe I/F

NANDNAND

NANDNAND

HMB

Performance benchmark 128GB TLC SSD

PCIe Gen3x1 NVMe (2CH DRAMless)

PCIe Gen3x1 NVMe HMB (2CH DRAMless)

SATA (4CH DRAM based)

Sequential Read 512KB

+28%

0 100 200 300 400 500 600 700

eMMC 5.1 (1CH DRAMless)

UFS (1CH DRAMless)

SATA (2CH DRAMless)

PCIe Gen3x1 NVMe (2CH DRAMless)

MB/s

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+188%

+28%

Test configuration: Chipset(Z97), Windows 8.1, Intel NVMe driver, CrystalDiskMark

Host Memory Buffer reduces latencies

eMMC 5.1

UFS

SATA (DRAMless)

PCIe Gen3x1 NVMe (DRAMless)

PCIe Gen3x1 NVMe HMB (DRAMless)

SATA (DRAM based)

Application to SSD IO Read Latency (QD=1, 4KB)

• Host Memory Buffer significantly reduces latencies:

– Boosts IOPS with 50% over SATA and 100% over eMMC

0 50 100 150 200 250 300

eMMC 5.1

Latency (us) lower is better

LUT access NAND Read NAND transfer Controller

Link Xfer Platform+adapter Host SW

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Performance benchmark 128GB TLC SSD

PCIe Gen3x1 NVMe (2CH DRAMless)

PCIe Gen3x1 NVMe HMB (2CH DRAMless)

SATA (4CH DRAM based)

Random Read 4KB / QD1

+10%

0 2 4 6 8

eMMC 5.1 (1CH DRAMless)

UFS (1CH DRAMless)

SATA (2CH DRAMless)

PCIe Gen3x1 NVMe (2CH DRAMless)

IOPS

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+100%

+50%

Test configuration: Chipset(Z97), Windows 8.1, Intel NVMe driver, CrystalDiskMark

Performance benchmark 128GB TLC SSD

PCIe Gen3x1 NVMe (2CH DRAMless)

PCIe Gen3x1 NVMe HMB (2CH DRAMless)

SATA (4CH DRAM based)

Random Read 4KB / QD32

-50%

0 20 40 60 80 100

eMMC 5.1 (1CH DRAMless)

UFS (1CH DRAMless)

SATA (2CH DRAMless)

PCIe Gen3x1 NVMe (2CH DRAMless)

IOPS

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+736%

+100%

Test configuration: Chipset(Z97), Windows 8.1, Intel NVMe driver, CrystalDiskMark

Client Workloads are light weight

• Review sites have developed trace based benchmarks

– Capturing user behavior on Windows machine

– Feeding commands to the SSD

• Example of queue depth distribution:

– QD1-4 cover >90% of all cases

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HMB Ecosystem development

• Operating system inbox driver & Bios support

– Windows, Linux, Android, etc

• Chipset to support PCIe as storage interface

– Coming in this year!

• Leading-edge SSD controller to support HMB• Leading-edge SSD controller to support HMB

– Marvell 88NV1140

• Deployment to PC OEMs

– Configuration, integration and qualification

• Marvell is working in all areas to drive HMB

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Summary

• A DRAMless SSD delivers good-enough performance and

capacity for an entry-level client PC system

• Moving from SATA to PCIe Gen3 NVMe increases

sequential read speeds and reduces latencies

• Enabling Host Memory Buffer boosts IOPS performance • Enabling Host Memory Buffer boosts IOPS performance

significantly

– 50-100% compared to other DRAMless solutions

• Marvell’s 88NV1140 enables this without adding BOM cost

• We are working with PC OEM to launch HMB soon

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The Opportunity...

• ...is bigger than you’d expect:

– Tablets/Convertables become productivity devices

– eMMC performance doesn’t scale

– PCIe Gen3x1 is a strong alternative

– Advanced Marvell NVMe SSD

controllers under development!

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BGA SSD M.2230 SSD$0.25 size

• The Future of NVMe is NOW!

– Marvell 88NV1140

– PCIe Gen3x1 NVMe 1.2 with Host Memory Buffer support

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