[SSD] Comparison of NVMe, SATA(1, 2, 3, express), PCIe

SSD主流介面：

1、标准SATA接口：对应的主流产品是2.5inch SSD，其外围尺寸一般为100mm（L）*70mm（W）*7mm（H）

2、mSATA接口：mSATA接口是SSD小型化的重要过程，对应的产品是mSATA SSD ，JEDEC尺寸规范为50.80±0.15mm（L）； 29.85±0.15mm（W）； 3.75±0.1mm（H）。

3、M.2接口：最初叫NGFF，全名是Next Generation Form Factor，尺寸比mSATA小巧，产品形态较mSATA也更为丰富，对应的产品有M.2 2230/M.2 2242/M.2 2260/M.2 2280/M.2 22110，在逐步取代mSATA。单面厚度是2.75mm，双面厚度为3.85mm。

4、 U.2接口：最初的名称是SFF-8639，在2015年的台北电脑展上改名为U.2，产品形态为2.5inch，支持PCIex4，所以PCIe Gen3x4速度可达4GB/S。U.2目前还是新兴产品，主要适用于工作站和服务器领域的企业级市场。

SATA版本	頻寬	理論速度
SATA Express	16Gb/s	1600MB/s
SATA 3.0	6Gb/s	600MB/s
SATA 2.0	3Gb/s	300MB/s
SATA 1.0	1.5Gb/s	150MB/s

HDD vs SATA vs. NVMe

The table below shows a comparison of HDD, SATA SSD and NVMe SSD. NVMe, as a protocol designed specifically for PCIe SSDs, delivers better performance than PCIe and SATA SSDs using the AHCI protocol.

Table 1. Comparison of NVMe and SATA 6 Gb/s.

Interface	PCIe		SATA 6 Gb/s
Protocol	NVMe Protocol (Optimized for flash SSDs)	AHCI Protocol (Optimized for mechanical HDDs)
Bandwidth	PCIe x2 or x4 lane	PCIe x2 or x4 lane	SATA 6 Gb/s
Form Factor	M.2/PCIe Expansion Card/U.2	M.2/PCIe Expansion Card	M.2/2.5" SSD
Max. Read Performance	>3000MB/s	>2000MB/s	>500MB/s
Max. Write Performance	>2000MB/s	>1500MB/s	>500MB/s

The following table compares bandwidths by generation. ATP's M.2 NVMe SSD is designed for a PCIe 3.0 interface and fits in a x4 lane, delivering up to 7.9 Gb/s transfer rate and up to 3.9 GB/s throughput.

Table 2. Bandwidth Comparison of PCIe and SATA.

PCIe				SATA
Generation	Transfer Rate	Throughput per Lane		Generation	Transfer Rate	Throughput
Gen1	2.5 Gb/s	x1: 250 MB/s	x4: 1 GB/s	Gen1	1.5 Gb/s	150 MB/s
Gen2	4.9 Gb/s	x1: 500 MB/s	x4: 2 GB/s	Gen2	3 Gb/s	300 MB/s
Gen3	7.9 Gb/s	x1: 984.6 MB/s	x4: 3.9 GB/s	Gen3	6 Gb/s	600 MB/s
Gen4	15.8 Gb/s	x1: 1,969 MB/s	x4: 7.8 GB/s

ref:

http://www.chinaflashmarket.com/Instructor/151736

https://zh.wikipedia.org/wiki/SATA

http://www.atpinc.com/Memory-insider/nvme-vs-sata-ssd-pcie-interface