New Enterprise SSD Controllers From Silicon Motion Phison FADU

In the past month, three SSD controller designers have announced new enterprise NVMe SSD controllers, bringing a wave of new competition to the high-end enterprise/datacenter SSD market. FADU is a relative newcomer to the market, having only released one previous SSD controller. Silicon Motion and Phison are both very familiar competitors, but they have been most successful with their client/consu

mer SSD controllers; they have been stepping up their enterprise controller efforts in recent years, but gaining ground in that market has been a slow process.

All three companies are now touting a new generation of enterprise NVMe SSD controllers that are more modern and mature. The three companies are poised to compete not just against each other, but against companies like Microchip/Microsemi and Marvell, who have a much longer track record of success in the enterprise SSD controller market.

Most of the major NAND flash memory manufacturers now use in-house controller designs for their enterprise and datacenter SSDs. Independent SSD controller designers sell to second-tier SSD brands, and also commonly sell directly to hyperscale cloud providers that are cutting out the middle-man. The business models in this market are quite flexible: customers may take just the controller ASIC and develop their own firmware, use turnkey or custom firmware developed by the controller vendor, or start from a reference design for the entire SSD and customize as needed. For the quickest time to market, some controller vendors will even arrange contract manufacturing of SSDs on behalf of their customers.

Silicon Motion SM8266 Controller

Silicon Motions new enterprise NVMe controller is the SM8266, a 16-channel design with a PCIe 4 x4 host interface.

Silicon Motions first enterprise NVMe controller was the SM2270. That had a bit of an odd design: it essentially combined two 8-channel controllers onto one chip behind a shared PCIe front-end supporting PCIe 3 x8. This allowed Silicon Motion to re-use a lot of the design of their very successful 8-channel client/consumer NVMe controllers while easily scaling up to a 16-channel solution. Silicon Motion hasnt shared a block diagram for the new SM8266, but we suspect theyre still using a similar split design since the SM8266 spec sheet mentions dual 32-bit DRAM interfaces.

The SM8266 uses the same 21mmx21mm package as the SM2270 but drops support for an x8 host interfacePCIe 4 x4 is plenty fast. The NAND interface now supports speeds up to 1200MT/s, the same as their recently-released SM2267 mainstream consumer NVMe controller, but a step behind the 1600MT/s supported by their upcoming SM2264 high-end consumer NVMe controller (both 8-channel designs). The DRAM interface on the SM8266 supports DDR4 and LPDDR3 at faster speeds than the SM2270, but again is lagging behind their latest consumer NVMe controllers that support LPDDR4(X).

The SM8266 supports up to 128 IO queues and optional NVMe features like Controller Memory Buffer (CMB) and up to 32 namespaces. Additionally, Silicon Motion can provide firmware implementing an Open Channel SSD interface or Key-Value SSD interface. Open Channel support was a major highlight of the SM2270, which was developed primarily for Alibabas use. However, most industry interest in Open Channel SSDs has moved on to the newer NVMe Zoned Namespaces standard.

The Silicon Motion SM8266 is available as a turnkey solution of the controller and firmware with SSD hardware reference designs. Silicon Motions subsidiary Shannon Systems is using the SM8266 in drives for hyperscale customers, expected to go into production in 2021.

        Silicon Motion Enterprise/Datacenter NVMe SSD Controllers
	
	
		
        SM8266
        SM2270
	
	
        DRAM Support
        2x 32bit DDR4-2400, LPDDR3-2133
        2x 32bit DDR4-2133, LPDDR3-1600
	
	
        Host Interface
        PCIe 4 x4
        PCIe 3 x8
	
	
        NAND Channels, Interface Speed
        16ch,
        1200 MT/s
        16ch
	
	
        CEs per Channel
        8
        8
	
	
        Sequential Read
        6550 MB/s
        3200 MB/s
	
	
        Sequential Write
        3100 MB/s
        2800 MB/s
	
	
        4KB Random Read IOPS
        950k
        800k
	
	
        4KB Random Write IOPS
        220k
        200k

Phison FX Series SSDs

The new Phison FX is a bit different from their previous enterprise/datacenter solutions, which have been -DC variants of their client/consumer SSD controllers. The Phison FX Series is a family of SSD reference designs, using a new controller that has not been separately named. The FX Series SSDs are U.2 15mm drives using 96L 3D TLC, with firmware that can be customized to suit the features required by each customer. The FXs controller is a 12-channel designthe widest Phison has ever put outbut the host interface is still just PCIe 3 x4. Despite the older PCIe gen3 host interface, the Phison FX uses their fourth-generation LDPC engine, the same as used in their E16 PCIe gen4 consumer SSD controller. Overall, its a clear step up from their 8-channel E12DC controller solution, but this is definitely the most conservative of the three new controller designs. However, that also means it is quick to market: Phison has already started shipping these drives.

        Phison Enterprise/Datacenter NVMe SSD Solutions
	
	
		
        FX Series
        E12DC
	
	
        Host Interface
        PCIe 3 x4
        PCIe 3 x4
	
	
        NAND Channels
        12
        8
	
	
        Sequential Read
        3400 MB/s
        3200 MB/s
	
	
        Sequential Write
        2500 MB/s
        1000 MB/s
	
	
        4KB Random Read IOPS
        560k
        460k
	
	
        4KB Random Write IOPS
        90k
        70k
	
	
        Performance based on 3.84TB 1 DWPD models

FADU Delta SSDs with FC4121 Controller

FADU is a fairly new SSD controller design firm, having been founded in 2015 and launched their first controller ASIC (FC3081) in 2018. This year, they are launching their second controller, the FC4121. The new controller moves to PCIe 4.0, widens the flash interface from 8 to 12 channels and increases the supported speeds from 800MT/s to 1200MT/swhich means the FC4121 can use almost all the extra bandwidth offered by the faster PCIe host interface.

        FADU Enterprise/Datacenter NVMe SSD Controllers
	
	
		
        FC4121
        FC3081
        Annapurna
	
	
        DRAM Support
        32bit DDR4, LPDDR4(X)
        32bit DDR4, LPDDR4
	
	
        Host Interface
        PCIe 4 x4
        PCIe 3 x4
	
	
        NAND Channels, Interface Speed
        12ch,
        1200MT/s
        8ch,
        800MT/s
	
	
        CEs per Channel
        16
        8
	
	
        Sequential Read
        7.1 GB/s
        3.5 GB/s
	
	
        Sequential Write
        5.1 GB/s
        2.65 GB/s
	
	
        4KB Random Read IOPS
        1675k
        820k
	
	
        4KB Random Write IOPS
        450k
        230k
	
	
        Performance based on 28% OP 3 DWPD using SK hynix 128L TLC

FADUs SSD controller architecture was the first to use RISC-V processor cores, with their previous FC3081 Annapurna controller featuring SiFives S51 cores. The controller architecture also features a variety of special-purpose hardware offloads to improve power efficiency and QoS. FADUs firmware can support a wide range of the more advanced optional NVMe features, including Controller Memory Buffer (CMB), Persistent Memory Region (PMR), SR-IOV virtualization, IO Determinism and Zoned Namespaces.

FADU provides their DELTA reference SSD designs based around the FC4121 controller, with both U.2 and EDSFF E1.S designs and firmware customization available. These designs are available either for customers to manufacture themselves, or customers can provide the NAND and FADU will arrange contract manufacturing of the private label SSDs.

Author: Billy Tallis

Date: 2020-11-25

URL: https://www.anandtech.com/show/16275/new-enterprise-ssd-controllers-from-silicon-motion-phison-fadu

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