Difference between revisions of "Rock3/hardware/emmc"

Revision as of 10:51, 21 January 2022

    ROCK 3 >  Hardware >  eMMC Module

Introduction

ROCK 3 doesn't come with on board storag. It uses the eMMC module instead. The benefits of eMMC module is that the user can choose the storage as they need, it reduces the main board SKU for us. Also, pluggable eMMC module makes switching OS possible.

eMMC module

Note: the green PCB and black PCB are the same, just color difference.

The eMMC socket on ROCK 3 uses two B2B connector to mount the eMMC module, the connector model is GB042 Series, one connector(34pin) for eMMC signal, the other(30pin) is for mount purpose only. This pinout of the 34pin is compatible with Odroid(Thanks Odroid for sharing their pinout).

• on ROCK 3: GB042-34P-H10 (plug-34pin) + GB042-30P-H10 (plug-30pin)
• on eMMC module: GB042-34S-H10 (socket-34pin) + GB042-30S-H10 (socket-30pin)

The eMMC chip we use is branded as Foresee, by Longsys, a Shenzhen embedded storage company, who acquired Lexar Brand in 2017.

• Download Foresee eMMC chip test report

Benchmarks

Below is the test we did on different brand eMMC chips.

dd

dd if=/dev/zero of=/dev/mmcblk1 bs=1G count=1 oflag=direct 
dd if=/dev/mmcblk1 of=/dev/null bs=1G count=1

result:

|      | brand    | read    | write    |
| ---- | -------- | ------- | -------- |
| 8G   | Sandisk  | 270MB/s | 39.4MB/s |
| 16G  | Sandisk  | 230MB/s | 79.6MB/s |
| 16G  | Kingston | 160MB/s | 50.1MB/s |
| 16G  | Foresee  | 189MB/s | 74.4MB/s |
| 16G  | Foresee  | 241MB/s | 79.5MB/s |
| 32G  | Sandisk  | 263MB/s | 139MB/s  |
| 32G  | Samsung  | 263MB/s | 78.3MB/s |
| 32G  | Kingston | 152MB/s | 87.2MB/s |
| 64G  | Sandisk  | 207MB/s | 100MB/s  |
| 64G  | Foresee  | 215MB/s | 148MB/s  |
| 64G  | Foresee  | 194MB/s | 148MB/s  |
| 128G | Toshiba  | 217MB/s | 143MB/s  |
| 64G | Sandisk | 295MB/s | 240MB/s |
| 32G | SiliconGo | 250MB/s | 135MB/s |

fio

1M Seq

fio --name=write --ioengine=libaio --iodepth=4 --rw=write --bs=1M --direct=1 --size=2G --numjobs=30 --runtime=60 --group_reporting --filename=/dev/mmcblk1
   
fio --name=read --ioengine=libaio --iodepth=4 --rw=read --bs=1M --direct=1 --size=2G --numjobs=30 --runtime=60 --group_reporting --filename=/dev/mmcblk1

4K random

fio --name=randwrite --ioengine=libaio --iodepth=4 --rw=randwrite --bs=4K --direct=1 --size=2G --numjobs=30 --runtime=60 --group_reporting --filename=/dev/mmcblk1
   
fio --name=randread --ioengine=libaio --iodepth=4 --rw=randread --bs=4K --direct=1 --size=2G --numjobs=30 --runtime=60 --group_reporting --filename=/dev/mmcblk1

result:

• Check full result at Github.

Dimension

• Download 2D .dxf file for eMMC module

eMMC2sd adapter

With eMMC2sd adapter board, the user can write the image from PC with uSD card reader. Adapter is not detected by some Lenovo/Dell internal UHS SD card readers. Read/write speeds with this adapter are significantly lower than on rock3.

USB3 eMMC Reader

• Check USB3 eMMC reader page