Brief note about Samsung SSD T7 on Raspberry Pi 4 which provided a nice boost to my personal GitLab instance at home. The performance is strongly limited due to Raspberry Pi device constraints, but it is still much better than regular HDD.
Operating system.
$ lsb_release -a
No LSB modules are available. Distributor ID: Debian Description: Debian GNU/Linux 11 (bullseye) Release: 11 Codename: bullseye
Kernel version.
$ uname -a
Linux raspberrypi 5.15.32-v8+ #1538 SMP PREEMPT Thu Mar 31 19:40:39 BST 2022 aarch64 GNU/Linux
Connect device.
$ dmesg
[...] [ 67.500588] usb 2-2: new SuperSpeed USB device number 2 using xhci_hcd [ 67.520740] usb 2-2: New USB device found, idVendor=04e8, idProduct=4001, bcdDevice= 1.00 [ 67.520772] usb 2-2: New USB device strings: Mfr=2, Product=3, SerialNumber=1 [ 67.520789] usb 2-2: Product: PSSD T7 [ 67.520804] usb 2-2: Manufacturer: Samsung [ 67.520817] usb 2-2: SerialNumber: S5TGNS0RC03342H [ 67.547875] scsi host0: uas [ 67.549446] scsi 0:0:0:0: Direct-Access Samsung PSSD T7 0 PQ: 0 ANSI: 6 [ 67.551863] sd 0:0:0:0: [sda] 976773168 512-byte logical blocks: (500 GB/466 GiB) [ 67.552053] sd 0:0:0:0: [sda] Write Protect is off [ 67.552071] sd 0:0:0:0: [sda] Mode Sense: 43 00 00 00 [ 67.552372] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA [ 67.553082] sd 0:0:0:0: [sda] Optimal transfer size 33553920 bytes [ 67.588033] sd 0:0:0:0: [sda] Attached SCSI disk [ 67.648863] sd 0:0:0:0: Attached scsi generic sg0 type 0 [...]
List connected devices.
$ lsusb
Bus 002 Device 002: ID 04e8:4001 Samsung Electronics Co., Ltd PSSD T7 Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 001 Device 002: ID 2109:3431 VIA Labs, Inc. Hub Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
List USB device details.
$ sudo lsusb -v -s 002:002
Bus 002 Device 002: ID 04e8:4001 Samsung Electronics Co., Ltd PSSD T7
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 3.20
bDeviceClass 0
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 9
idVendor 0x04e8 Samsung Electronics Co., Ltd
idProduct 0x4001
bcdDevice 1.00
iManufacturer 2 Samsung
iProduct 3 PSSD T7
iSerial 1 S5TGNS0RC03342H
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 0x0079
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0x80
(Bus Powered)
MaxPower 896mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 80 Bulk-Only
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0400 1x 1024 bytes
bInterval 0
bMaxBurst 15
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0400 1x 1024 bytes
bInterval 0
bMaxBurst 15
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 1
bNumEndpoints 4
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 98
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0400 1x 1024 bytes
bInterval 0
bMaxBurst 15
MaxStreams 32
Data-in pipe (0x03)
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0400 1x 1024 bytes
bInterval 0
bMaxBurst 15
MaxStreams 32
Data-out pipe (0x04)
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0400 1x 1024 bytes
bInterval 0
bMaxBurst 15
MaxStreams 32
Status pipe (0x02)
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x04 EP 4 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0400 1x 1024 bytes
bInterval 0
bMaxBurst 0
Command pipe (0x01)
Binary Object Store Descriptor:
bLength 5
bDescriptorType 15
wTotalLength 0x002a
bNumDeviceCaps 3
USB 2.0 Extension Device Capability:
bLength 7
bDescriptorType 16
bDevCapabilityType 2
bmAttributes 0x0000f41e
BESL Link Power Management (LPM) Supported
BESL value 1024 us
Deep BESL value 61440 us
SuperSpeed USB Device Capability:
bLength 10
bDescriptorType 16
bDevCapabilityType 3
bmAttributes 0x00
wSpeedsSupported 0x000e
Device can operate at Full Speed (12Mbps)
Device can operate at High Speed (480Mbps)
Device can operate at SuperSpeed (5Gbps)
bFunctionalitySupport 1
Lowest fully-functional device speed is Full Speed (12Mbps)
bU1DevExitLat 10 micro seconds
bU2DevExitLat 2047 micro seconds
SuperSpeedPlus USB Device Capability:
bLength 20
bDescriptorType 16
bDevCapabilityType 10
bmAttributes 0x00000001
Sublink Speed Attribute count 1
Sublink Speed ID count 0
wFunctionalitySupport 0x1100
bmSublinkSpeedAttr[0] 0x000a4030
Speed Attribute ID: 0 10Gb/s Symmetric RX SuperSpeedPlus
bmSublinkSpeedAttr[1] 0x000a40b0
Speed Attribute ID: 0 10Gb/s Symmetric TX SuperSpeedPlus
can't get debug descriptor: Resource temporarily unavailable
Device Status: 0x000c
(Bus Powered)
U1 Enabled
U2 Enabled
Perform cached/buffered read on Raspberry Pi 4.
$ sudo hdparm -t -T /dev/sda
/dev/sda: Timing cached reads: 2038 MB in 2.00 seconds = 1020.29 MB/sec Timing buffered disk reads: 874 MB in 3.00 seconds = 291.21 MB/sec
Perform cached/buffered read on desktop PC.
$ sudo hdparm -t -T /dev/sda
/dev/sda: Timing cached reads: 35130 MB in 2.00 seconds = 17596.74 MB/sec Timing buffered disk reads: 2620 MB in 3.02 seconds = 866.55 MB/sec
Perform direct read on Raspberry Pi 4.
$ sudo hdparm -t --direct /dev/sda
/dev/sda: Timing O_DIRECT disk reads: 948 MB in 3.00 seconds = 315.85 MB/sec
Perform direct read on desktop PC.
$ sudo hdparm -t --direct /dev/sda
/dev/sda: Timing O_DIRECT disk reads: 2036 MB in 3.00 seconds = 678.17 MB/sec
Perform write test using dd on Raspberry Pi 4.
$ sudo dd if=/dev/zero of=/dev/sda bs=256M count=16 oflag=dsync
16+0 records in 16+0 records out 4294967296 bytes (4.3 GB, 4.0 GiB) copied, 23.6042 s, 182 MB/s
Perform write test using dd on desktop PC.
$ sudo dd if=/dev/zero of=/dev/sda bs=256M count=16 oflag=dsync
16+0 records in 16+0 records out 4294967296 bytes (4.3 GB, 4.0 GiB) copied, 7.83263 s, 548 MB/s
Perform read test using dd on Raspberry Pi 4.
$ sudo dd if=/dev/sda of=/dev/null bs=256M count=16
16+0 records in 16+0 records out 4294967296 bytes (4.3 GB, 4.0 GiB) copied, 13.8206 s, 311 MB/s
Perform read test using dd on desktop PC.
$ sudo dd if=/dev/sda of=/dev/null bs=256M count=16
16+0 records in 16+0 records out 4294967296 bytes (4.3 GB, 4.0 GiB) copied, 5.20054 s, 826 MB/s
This is a gnome-disks benchmark on Ubuntu 22.04 which was used as the above-mentioned desktop PC.
