Какова реальная скорость (поток, задержка) USB3 и USB2 по SATA?
Легко найти сравнения скорости потоковой передачи, но труднее найти сравнения задержек в одной и той же настройке.
Ответьте, чтобы подписаться на него немедленно.
На материнской плате ASUS Z87 с Intel i7-4770K с большим объемом памяти и Ubuntu 14.10, грубое сравнение производительности SSD-накопителя Intel 80 ГБ (X25-M) первого поколения с использованием утилиты ioping в файловой системе ext4, приблизительная оценка производительности чтения:
SPEC: 250MB/sec,
SATA: 240MB/sec, 1000 iops, 1ms latency
USB3: 190MB/sec, 750 iops, 1.3ms latency
USB2: 43MB/sec, 200 iops, 6ms latency
Конечно, это будет отличаться для разных настроек. Смысл этой таблицы состоял в том, чтобы добавить некоторую статистику задержки и iops в не теоретическое сравнение. Остальное ниже - это просто подробности вышеизложенного.
Более подробная информация приводится ниже
All Tests Run On An Intel 80GB First-Gen Drive, X25-M.
Direct-Access ATA INTEL SSDSA2M080 02HA PQ: 0 ANSI: 5
Intel Posted X25-M Drive Specs:
Read: 250MB/s
Write: 70MB/s
Latency Read: 65us
Latency Write 85us
IOPS: read=35k. write=300 to 6600
Motherboard: Asus Z87 Gryphon w/ USB 3.0 port.
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on the SATA bus:
# ioping -RL .
--- . (ext4 /dev/sdb1) ioping statistics ---
2.8 k requests completed in 3.0 s, 952 iops, 238.0 MiB/s
min/avg/max/mdev = 999 us / 1.1 ms / 2.1 ms / (85 us)
# ioping -RL .
--- . (ext4 /dev/sdb1) ioping statistics ---
2.8 k requests completed in 3.0 s, 956 iops, 239.2 MiB/s
min/avg/max/mdev = 1.0 ms / 1.0 ms / 7.6 ms / (149 us)
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on the USB 3.0 superspeed bus:
Bus 003 Device 011: ID 152d:2509 JMicron Technology Corp. / JMicron USA Technology Corp. JMS539 SuperSpeed SATA II 3.0G Bridge
# ioping -R .
--- . (ext4 /dev/sdd1) ioping statistics ---
11.3 k requests completed in 3.0 s, 3.8 k iops, 14.8 MiB/s
min/avg/max/mdev = 247 us / 264 us / 4.6 ms / (49 us)
# ioping .
4.0 KiB from . (ext4 /dev/sdd1): request=1 time=1.6 ms
4.0 KiB from . (ext4 /dev/sdd1): request=2 time=333 us
... ^C
--- . (ext4 /dev/sdd1) ioping statistics ---
12 requests completed in 11.5 s, 2.3 k iops, 9.1 MiB/s
min/avg/max/mdev = 290 us / 427 us / 1.6 ms / (344 us)
# ioping -RL .
--- . (ext4 /dev/sdd1) ioping statistics ---
2.2 k requests completed in 3.0 s, 748 iops, 187.0 MiB/s
min/avg/max/mdev = 1.3 ms / 1.3 ms / 3.6 ms / (96 us)
----------------------------------------------------------------
on the USB 2.0 high-speed bus:
# ioping -R .
--- . (ext4 /dev/sdd1) ioping statistics ---
509 requests completed in 3.0 s, 170 iops, 42.6 MiB/s
min/avg/max/mdev = 5.8 ms / 5.9 ms / 6.3 ms / (67 us)
# ioping -RL .
--- . (ext4 /dev/sdd1) ioping statistics ---
510 requests completed in 3.0 s, 170 iops, 42.7 MiB/s
min/avg/max/mdev = 5.8 ms / 5.9 ms / 6.3 ms / (42 us)
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USB3 Bridge Device
Bus 003 Device 011: ID 152d:2509 JMicron Technology Corp. / JMicron USA Technology Corp. JMS539 SuperSpeed SATA II 3.0G Bridge
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.10
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x152d JMicron Technology Corp. / JMicron USA Technology Corp.
idProduct 0x2509 JMS539 SuperSpeed SATA II 3.0G Bridge
bcdDevice 1.00
iManufacturer 1 JMicron
iProduct 11 Usb production
iSerial 3 00A123456A8D
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 32
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 4 USB Mass Storage
bmAttributes 0xc0
Self Powered
MaxPower 2mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 80 Bulk-Only
iInterface 6 MSC Bulk-Only Transfer
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Binary Object Store Descriptor:
bLength 5
bDescriptorType 15
wTotalLength 42
bNumDeviceCaps 3
USB 2.0 Extension Device Capability:
bLength 7
bDescriptorType 16
bDevCapabilityType 2
bmAttributes 0x00000002
Link Power Management (LPM) Supported
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 32 micro seconds
Container ID Device Capability:
bLength 20
bDescriptorType 16
bDevCapabilityType 4
bReserved 0
ContainerID {00010203-0405-0607-0800-000000000000}
Device Status: 0x0001
Self Powered