Comparison of Raspberry Pi vs Beaglebone Black vs Banana Pi

Update (2015-2): I'll update the below when I get more info on the new BCM2836 chip used in the Raspberry Pi Generation 2 model B. It CPU performance should jump up by about six, the RAM has doubled, but the GPU is the same as is everything else. RAM performance will be the same, no clocking improvement, just size. The quad core CPU (ARMv7) does now have NEON support so SIMD, should improve data processing ability. But the real bottleneck to the RPi is getting data into and out of the CPU from the real world, it is like a giant head sitting on a straw.

CPU

From each of the /proc/cpuinfo files shown below, in theory if an application is single threaded the Banana Pi should win, and if it is multithreaded the Banana Pi should still win. I have not run any direct benchmark, just looking at the BogoMIPS and the Features supported by each ARM chip.

Raspberry Pi (Model A,B,B+,A+ all have the same ARM1176JZF-S)
------------
Processor       : ARMv6-compatible processor rev 7 (v6l)
BogoMIPS        : 697.95
Features        : swp half thumb fastmult vfp edsp java tls
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x0
CPU part        : 0xb76
CPU revision    : 7

Hardware        : BCM2708
Revision        : 000f

BeagleBone Black
----------------
processor    : 0
model name    : ARMv7 Processor rev 2 (v7l)
BogoMIPS    : 990.68
Features    : swp half thumb fastmult vfp edsp thumbee neon vfpv3 tls
CPU implementer    : 0x41
CPU architecture: 7
CPU variant    : 0x3
CPU part    : 0xc08
CPU revision    : 2

Hardware    : Generic AM33XX (Flattened Device Tree)
Revision    : 0000
Serial        : 0000000000000000


Banana Pi (The Banana Pro has the same Allwinner A20)
---------
Processor       : ARMv7 Processor rev 4 (v7l)
processor       : 0
BogoMIPS        : 2004.17

processor       : 1
BogoMIPS        : 2011.05

Features        : swp half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x0
CPU part        : 0xc07
CPU revision    : 4

Hardware        : sun7i
Revision        : 0000

Video/GPU

Raspberry Pi:  Broadcom VideoCore IV (Graphics and compute) 24 GFLOPS
Beaglebone Black: PowerVR SGX530 (200 MHz) (Graphics, video encoding, decoding only) 1.6 GFLOPS
 Banana Pi: ARM Mali400MP2 dual GPU core (Grahpics, video encoding, decoding only) 6.3 GFLOPS 

RAM

Raspberry Pi ( A, A+, B rev 1): 256MiB DDR
Raspberry Pi (B rev 2, B+): 512MiB DDR
BeagleBone Black: 512MiB DDR3L
Banana Pi: 1024MiB DDR3

[DDR3 is 1.35 volt and DDR3L 1.25 volt (lower power = less heat = longer life)]

 

USB

Raspberry Pi A: 1 x Standard A host port (direct).
Raspberry Pi B: 2 x Standard A host port (via hub with Ethernet).
Raspberry Pi A+: 1 x Standard A host port (direct).
Raspberry Pi B+: 4 x Standard A host port (via hub with Ethernet).
Beaglebone Black: 1 x Standard A host port (direct) 1x mini B device port (direct)
Banana Pi: 2 x Standard A host port (direct) 1x mini AB OTG port (direct)
 

Ethernet

Raspberry Pi (B, B+): 10/100Mbps (shared USB)
Beaglebone Black: 10/100Mbps
Banana Pi: 10/100/1000Mbps

Storage

SD/microSD

Raspberry Pi A,B: SD card
Raspberry Pi A+, B+:  microSD card
Beaglebone Black:  microSD card
Banana Pi:  SD card

8-bit eMMC 

Raspberry Pi: None
Beaglebone Black ((Rev B): 2 GB Ångström pre-installed
Beaglebone Black ((Rev C): 4 GB Debian pre-installed
Banana Pi: None

SATA

Raspberry Pi: None
Beaglebone Black: None
Banana Pi: SATA 2.0

Me personally I hate devices with inbuilt flash, 3000-5000 writes per block and the device ready for the bin.

GPIO/Low-level peripherals

Raspberry Pi A, B rev 1: UART, SPI, 2x I²C,MIPI CSI-2, (not yet enabled DSI, CEC)
                                       8-17GPIO pins
Raspberry Pi B rev 2: UART, SPI, 2x I²C,MIPI CSI-2, (not yet enabled DSI, CEC)
                                  12-21GPIO pins

Raspberry Pi A+, B+: UART, SPI, 2x I²C,MIPI CSI-2, (not yet enabled DSI, CEC)
                                   EEPROM ID feature for auto-configuration with add-on "HAT" boards
                                   21-30GPIO pins

Beaglebone Black: 4xUART(1xTX only), 8x PWM, LCD, GPMC, MMC1, 2x SPI, 2x I²C, 7xADC(1.8v), 2x CAN bus, 4 Timers, 25xPRU
                                  65 GPIO pins
Banana Pi:  UART, SPI, I²C, CAN, ADC, PWM
                  CSI (or 21 additional GPIO pins), LCD display LVDS (or 36 additional GPIO pins)
                  7-17 GPIO pins (or 7-74 GPIO pins if CSI and LCD are re-purposed)
                  IR receiver
                  On board microphone

Overall I'd probably pick the Beaglebone Black as having the best GPIO/Low-level peripherals support (and very easy access to the pins).

Power

Raspberry Pi A: 500mA-1000mA
Raspberry Pi B: 700-1000mA
Raspberry Pi A+:  500mA-2000mA
Raspberry Pi B+: 600-2000mA
Beaglebone Black: 300–500 mA @5 V
Banana Pi: 200mA*-2000mA (*requires 700-800mA during boot)

Weight

Raspberry Pi A:  45 g (1.6 oz)
Raspberry Pi B:  45 g (1.6 oz)
Raspberry Pi A+:   23 g (0.81 oz)
Raspberry Pi B+:  45 g (1.6 oz)
Beaglebone Black: 39.68 g (1.400 oz)
Banana Pi:  48 g (1.7 oz)



My conclusion would be if it is light weight I needed, then I'd go with a Pro Trinket (2.6g/0.09oz), unless I needed a 1920x1080HD camera as well then it would be the Raspberry Pi A+ (23g/0.81oz) with a camera module (3g/0.11oz). If it was easily accessible GPIO that I needed, with loads of inputs and outputs I'd pick the Beaglebone Black (It is a great piece of open hardware) 7ADC is nice. And finally if it was shoving large amounts of data about fast, or processing that data, I'd pick the Banana Pi (With SATA 2.0, Gigabit Ethernet and 1GiB of RAM it is an impressive piece of kit) or it's newer incarnation of hardware the Banana Pro (with builtin WiFi).

There are larger communities built up around the Raspberry Pi and Beaglebone Black, than there is around the Banana Pi/Pro hardware.  So if you have a problem, sometimes you may have to solve it yourself rather than looking for a quick fix from someone else in the community  who had the same problem already.

Part two: Raspberry Pi WiFi throughput test

Update (2015-02): There will be little to no change in throughput performance from the new Raspberry Pi Generation 2 Model B (900MHz quad-core ARM Cortex-A7 BCM2836) over the older Raspberry Pi Model B+ (700MHz ARM11 BCM2835), since the USB performance bottleneck is still the LAN9514 USB/Ethernet controller and will not be improved by additional CPU or RAM.

Update (2014-07): There is a new RPi model B+ with 4 USB ports (well 5 in fact when you include ethernet using a LAN9514 chip instead of 3 ports using the LAN9512 in the model B). Just to be clear the tests below were done on the model B. If and when I repeat the the tests with a model B+ I do not expect to see better performance.



When I looked at the performance of 802.11n I only looked at the highest possible throughput setting that I could setup (In my case a 150Mbps on a TP-LINK WN725N which is software compatible with 8188eu USB Wifi dongle). But not everyone has a 802.11n WiFi adapter, so I decided to run the tests again but this time to force the Wifi to lower performance modes, to see the different throughput rates. This is wireless so my results will differ than anyone else's but they should give a idea of what kind of real world (non-marketing) throughput to expect.

But one thing to remember is that these are maximum throughput rates, since all WiFi data received is being thrown away. If the data was written to an SD card then four other things would need to be factored in: The make and model of the SD card, the read performance of the card; the write performance of the card and most importantly the age of the card. The more writes you do to a SD card the slower it's overall performance becomes, anyhow the initial performance of most SD cards can be found here

The setup is exactly the same as last time. A midrange Linux PC running a nginx webserver serving a 100MiB file from a 256MiB RAM disk. The data flows through a 1Gigabit/sec full duplex NIC to a home cable modem from there it is sent via WiFi to my USB Raspberry Pi WiFi NIC and finally sent to /dev/null to eliminate any SD/harddisk access times. I set the speed on the broadband router to three different settings:
54Mbit/sec = disable 802.11n.

72Mbit/sec = 802.11n 20MHz bandwidth,
150Mbit/sec = 802.11n 40MHz bandwidth,

And after setting the channel and speed, I confirmed both had actually changed correctly on the RPi with the iwconfig command. I also download the same 100MiB file 3 times in a row and these are the numbers MiB/second numbers on each row below.

e.g.
wget http://192.168.1.100/ramdisk/speedtest-100MB.bin -O /dev/null ; wget http://192.168.1.100/ramdisk/speedtest-100MB.bin -O /dev/null ; wget http://192.168.1.100/ramdisk/speedtest-100MB.bin -O /dev/null


pi@raspberrypi ~ $ sudo iwconfig wlan0
wlan0     IEEE 802.11bgn  ESSID:"**********"  Nickname:"<WIFI@REALTEK>"
          Mode:Managed  Frequency:2.472 GHz  Access Point: 80:C6:AB:**:**:**
          Bit Rate: 54 Mb/s   Sensitivity:0/0
          Retry:off   RTS thr:off   Fragment thr:off
          Encryption key:****-****-****-****-****-****-****-****   Security mode:open
          Power Management:off
          Link Quality=100/100  Signal level=100/100  Noise level=0/100
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0
pi@raspberrypi ~ $


802.11a
802.11 band: 2.4GHz
Bit Rate: 54Mb/s  (6.44MiB/sec)
Bandwidth 20MHz 
Download rate: 1.51 MiB/sec <-> 3.37 MiB/sec
Download rate: 12.67 Mbit/sec <->  28.27 Mbit/sec
channel  1  Frequency:2.412 GHz  2.10 MB/s 2.14 MB/s 2.12 MB/s
channel  2  Frequency:2.417 GHz  1.83 MB/s 1.88 MB/s 1.87 MB/s
channel  3  Frequency:2.422 GHz  1.51 MB/s 1.57 MB/s 1.55 MB/s
channel  4  Frequency:2.427 GHz  1.61 MB/s 1.64 MB/s 1.65 MB/s
channel  5  Frequency:2.432 GHz  2.30 MB/s 2.29 MB/s 2.28 MB/s
channel  6  Frequency:2.437 GHz  2.48 MB/s 2.45 MB/s 2.44 MB/s
channel  7  Frequency:2.442 GHz  2.92 MB/s 2.91 MB/s 2.93 MB/s
channel  8  Frequency:2.447 GHz  2.96 MB/s 2.98 MB/s 2.97 MB/s
channel  9  Frequency:2.452 GHz  2.72 MB/s 2.74 MB/s 2.69 MB/s
channel 10  Frequency:2.457 GHz  3.00 MB/s 3.06 MB/s 3.05 MB/s
channel 11  Frequency:2.462 GHz  2.98 MB/s 3.01 MB/s 3.05 MB/s
channel 12  Frequency:2.467 GHz  3.22 MB/s 3.21 MB/s 3.23 MB/s
channel 13  Frequency:2.472 GHz  3.36 MB/s 3.37 MB/s 3.34 MB/s



802.11n
802.11 band: 2.4GHz
Bit Rate: 72  Mb/s (8.58MiB/sec)
Bandwidth 20MHz
Download rate: 3.77 MiB/sec <-> 6.15 MiB/sec
Download rate: 31.63 Mbit/sec <->  51.59 Mbit/sec

channel  1  Frequency:2.412 GHz  4.47 MiB/s 4.68 MiB/s 4.74 MiB/s
channel  2  Frequency:2.417 GHz  4.28 MiB/s 4.32 MiB/s 4.10 MiB/s
channel  3  Frequency:2.422 GHz  3.82 MiB/s 3.82 MiB/s 3.77 MiB/s
channel  4  Frequency:2.427 GHz  4.08 MiB/s 4.06 MiB/s 4.22 MiB/s
channel  5  Frequency:2.432 GHz  5.15 MiB/s 4.84 MiB/s 4.97 MiB/s
channel  6  Frequency:2.437 GHz  5.27 MiB/s 5.19 MiB/s 5.31 MiB/s
channel  7  Frequency:2.442 GHz  5.47 MiB/s 5.61 MiB/s 5.76 MiB/s
channel  8  Frequency:2.447 GHz  5.92 MiB/s 6.15 MiB/s 6.04 MiB/s
channel  9  Frequency:2.452 GHz  5.45 MiB/s 5.44 MiB/s 5.41 MiB/s
channel 10  Frequency:2.457 GHz  6.04 MiB/s 6.12 MiB/s 6.02 MiB/s
channel 11  Frequency:2.462 GHz  5.72 MiB/s 5.63 MiB/s 5.67 MiB/s
channel 12  Frequency:2.467 GHz  5.78 MiB/s 5.85 MiB/s 5.74 MiB/s
channel 13  Frequency:2.472 GHz  6.07 MiB/s 6.11 MiB/s 6.08 MiB/s



802.11n
802.11 band: 2.4GHz
Bit Rate: 150  Mb/s (17.88MiB/sec)
Bandwidth 40MHz
Download rate: 4.03 MiB/sec <-> 9.67 MiB/sec
Download rate: 33.81 Mbit/sec <-> 81.11 Mbit/sec

channel  1L Frequency:2.412 GHz  8.92 MiB/s 9.24 MiB/s 7.66 MiB/s
channel  2L Frequency:2.417 GHz  8.46 MiB/s 8.99 MiB/s 5.70 MiB/s
channel  3L Frequency:2.422 GHz  9.16 MiB/s 8.41 MiB/s 9.32 MiB/s
channel  4L Frequency:2.427 GHz  5.19 MiB/s 8.62 MiB/s 8.31 MiB/s
channel  5L Frequency:2.432 GHz  4.23 MiB/s 4.37 MiB/s 4.74 MiB/s
channel  6L Frequency:2.437 GHz  4.03 MiB/s 7.91 MiB/s 9.38 MiB/s
channel  7L Frequency:2.442 GHz  8.22 MiB/s 8.01 MiB/s 8.03 MiB/s
channel  8L Frequency:2.447 GHz  9.58 MiB/s 8.12 MiB/s 9.67 MiB/s
channel  9L Frequency:2.452 GHz  5.47 MiB/s 5.26 MiB/s 5.35 MiB/s

channel  5U Frequency:2.432 GHz  7.91 MiB/s 7.92 MiB/s 9.48 MiB/s
channel  6U Frequency:2.437 GHz  7.58 MiB/s 9.05 MiB/s 7.58 MiB/s
channel  7U Frequency:2.442 GHz  7.10 MiB/s 9.48 MiB/s 9.41 MiB/s
channel  8U Frequency:2.447 GHz  9.52 MiB/s 9.38 MiB/s 9.15 MiB/s
channel  9U Frequency:2.452 GHz  9.42 MiB/s 9.22 MiB/s 9.07 MiB/s
channel 10U Frequency:2.457 GHz  8.77 MiB/s 9.46 MiB/s 8.10 MiB/s
channel 11U Frequency:2.462 GHz  8.65 MiB/s 9.30 MiB/s 9.41 MiB/s
channel 12U Frequency:2.467 GHz  8.64 MiB/s 9.01 MiB/s 9.34 MiB/s
channel 13U Frequency:2.472 GHz  9.02 MiB/s 9.55 MiB/s 8.45 MiB/s

My Wifi router supports four 20MHz channels in the 5GHz band (36, 40, 44, 48 [5.180GHz 5.200GHz 5.220GHz 5.240GHz]) but unfortunately my TP-LINK nano USB WN725N only supports the 2.4GHz band (2.4 ~ 2.4835GHz), so I can't test the throughputs in the 5GHz band. Which is a pity, because higher RF frequency means lower penetration depth into objects, so I would expect less interference at higher frequencies.

Raspberry Pi USB disk throughput test

Update (2015-02): There will be little to no change in throughput performance from the new Raspberry Pi Generation 2 Model B (900MHz quad-core ARM Cortex-A7 BCM2836) over the older Raspberry Pi Model B+ (700MHz ARM11 BCM2835), since the USB performance bottleneck is still the LAN9514 USB/Ethernet controller and will not be improved by additional CPU or RAM.

Update (2014-07): There is a new RPi model B+ with 4 USB ports (well 5 in fact when you include ethernet using a LAN9514 chip instead of 3 ports using the LAN9512 in the model B). Just to be clear the tests below were done on the model B. If and when I repeat the the tests with a model B+ I do not expect to see better performance.

Hardware Configuration:

Raspberry Pi model B - 512MB model, 128MB of RAM allocated to GPU, no overclocking
Inbuilt 10/100 NIC is connected.
Top USB port is a 2TB USB hard disk drive.
Bottom USB port is empty.

So no keyboard, no mouse. In an ideal world we would have the inbuilt USB NIC disabled (after setting the date and time) as well, but it appears that the RPi has the network module compiled directly into the kernel.
pi@raspberrypi ~ $ zgrep -i smsc95xx /proc/config.gz
CONFIG_USB_NET_SMSC95XX=y
pi@raspberrypi ~ $ sudo modprobe -r smsc95xx
FATAL: Module smsc95xx is builtin.

So to just have a hard disk  and RPi (and internal 3 port USB hub) would require me to recompile the kernel, which would make the results slightly off standard

The HDD that I'm using has an Internal write rate of about 100MiB/sec, so USB throughput should be the cause of any performance bottleneck.

 

Prerequisites:

sudo apt-get install at expect expect-dev

ext2, ext3, ext4, vfat file system write tests 

I split a 2 TB disk into four equal sized partitions.

pi@raspberrypi ~ $ lsusb -t
/:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=dwc_otg/1p, 480M
    |__ Port 1: Dev 2, If 0, Class=hub, Driver=hub/3p, 480M
        |__ Port 1: Dev 3, If 0, Class=vend., Driver=smsc95xx, 480M
        |__ Port 2: Dev 4, If 0, Class=stor., Driver=usb-storage, 480M

pi@raspberrypi ~ $ sudo fdisk -l /dev/sda

Disk /dev/sda: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x1ba9000c

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1            2048   976758827   488378390   83  Linux
/dev/sda2       976758828  1953515607   488378390   83  Linux
/dev/sda3      1953515608  2930272387   488378390   83  Linux
/dev/sda4      2930272388  3907029167   488378390    c  W95 FAT32 (LBA)

pi@raspberrypi ~ $ sudo mkfs.ext2 -L ext2 /dev/sda1
pi@raspberrypi ~ $ sudo mkfs.ext3 -L ext3 /dev/sda2
pi@raspberrypi ~ $ sudo mkfs.ext4 -L ext4 /dev/sda3
pi@raspberrypi ~ $ sudo mkfs.vfat -n vfat /dev/sda4
pi@raspberrypi ~ $ cd /media 
pi@raspberrypi /media $ sudo mkdir ext2 ext3 ext4 vfat




pi@raspberrypi ~ $ at midnight
warning: commands will be executed using /bin/sh
at> /home/pi/write-throughputtest.exp 2>&1 >/home/pi/at.output 
at> ^D




pi@raspberrypi ~ $

 

pi@raspberrypi ~ $ cat write-throughputtest.exp
#!/usr/bin/expect -f
#
# This Expect script was generated by autoexpect on Sun Mar 30 16:43:25 2014
set force_conservative 0  ;# set to 1 to force conservative mode even if
                          ;# script wasn't run conservatively originally
if {$force_conservative} {
        set send_slow {1 .1}
        proc send {ignore arg} {
                sleep .1
                exp_send -s -- $arg
        }
}



set timeout -1
spawn $env(SHELL)
match_max 100000
expect "$"
send -- "/bin/bash"
expect "pi@raspberrypi"
send -- "sudo /bin//bash\r"
expect "root@raspberrypi"
send -- "script /home/pi/output-root.txt\r"
expect "Script started, file is /home/pi/output-root.txt\r"
send -- "mount /dev/sda1 /media/ext2\r"
expect "root@raspberrypi"
send -- "mount /dev/sda2 /media/ext3\r"
expect "root@raspberrypi"
send -- "mount /dev/sda3 /media/ext4\r"
expect "root@raspberrypi"
send -- "mount /dev/sda4 /media/vfat\r"
expect "root@raspberrypi"
send -- "/home/pi/write-throughputtest.sh /media/ext2\r"
expect "root@raspberrypi"
send -- "/home/pi/write-throughputtest.sh /media/ext3\r"
expect "root@raspberrypi"
send -- "/home/pi/write-throughputtest.sh /media/ext4\r"
expect "root@raspberrypi"
send -- "/home/pi/write-throughputtest.sh /media/vfat\r"
expect "root@raspberrypi"
send -- "exit\r"
expect "Script done, file is /home/pi/output-root.txt\r"
send -- "exit\r"
expect "pi@raspberrypi"
send -- "exit\r"
expect "$"
send -- "exit\r"
expect eof 

pi@raspberrypi ~ $ cat write-throughputtest.sh
#!/bin/sh
DEST=$1

# 18 x 1GiB = 18GiB
# assuming maximum write 40MiB/sec this should take 8 minutes
# assuming poor write speed of 5 MiB/sec this should take 2 hours
# either way one pass should happen within 12 hours
echo touch $DEST/testbegin-write-starttime
touch $DEST/testbegin-write-starttime
date
echo sync
sync
date

for BS in 8 16 32 64 128 256 \
        512 1024 2048 4096 8192 16384 \
        32768 65536 131072 262144 524288 1048576

do
 COUNT=`expr 1073741824 / $BS`
echo touch $DEST/${BS}b-write-starttime
 touch $DEST/${BS}b-write-starttime
date
echo dd if=/dev/zero of=$DEST/${BS}b-data bs=${BS} count=${COUNT}
 dd if=/dev/zero of=$DEST/${BS}b-data bs=${BS} count=${COUNT}
date
echo touch $DEST/${BS}b-write-endtime
 touch $DEST/${BS}b-write-endtime
date
echo sync
 sync
date
# any delay caused by sync will show up on next starttime
done

echo touch $DEST/testover-write-endtime
touch $DEST/testover-write-endtime
date

pi@raspberrypi ~ $ cat read-throughputtest.sh
#!/bin/sh
SRCE=$1

# 18 x 1GiB = 18GiB
# assuming maximum read 40MiB/sec this should take 8 minutes
# assuming poor read speed of 5 MiB/sec this should take 2 hours
# This script assumes that write-throughputtest.sh was run
# previously to generate the data files.

date
echo sync
sync
date

for BS in 8 16 32 64 128 256 \
        512 1024 2048 4096 8192 16384 \
        32768 65536 131072 262144 524288 1048576

do
 COUNT=`expr 1073741824 / $BS`
date
echo dd of=/dev/null if=$SRCE/${BS}b-data bs=${BS} count=${COUNT}
 dd of=/dev/null if=$SRCE/${BS}b-data bs=${BS} count=${COUNT}
date
echo sync
 sync
date
done

date

pi@raspberrypi ~ $

 Results

USB disk performance check Raspberry Pi normal USB (internal 3 port hub)

Raspberry Pi Model B USB disk write results
-----------------------------------------------------------
block             filesystem type
size   -------------------------------------------            
(bytes)ext2       ext3       ext4       vfat
8       0.2 MiB/s  0.3 MiB/s  0.3 MiB/s  0.8 MiB/s
16      0.4 MiB/s  0.5 MiB/s  0.6 MiB/s  1.5 MiB/s
32      0.9 MiB/s  1.0 MiB/s  1.1 MiB/s  2.9 MiB/s
64      2.5 MiB/s  1.8 MiB/s  1.9 MiB/s  4.4 MiB/s
128     4.7 MiB/s  3.2 MiB/s  3.5 MiB/s  6.3 MiB/s
256     7.4 MiB/s  5.5 MiB/s  6.1 MiB/s  9.4 MiB/s
512    10.6 MiB/s  8.5 MiB/s  9.5 MiB/s 12.2 MiB/s
1k     14.9 MiB/s 11.3 MiB/s 13.8 MiB/s 13.1 MiB/s
2k     18.4 MiB/s 14.2 MiB/s 18.6 MiB/s 15.1 MiB/s
4k     20.8 MiB/s 17.7 MiB/s 22.5 MiB/s 17.0 MiB/s
8k     21.3 MiB/s 18.6 MiB/s 22.8 MiB/s 16.7 MiB/s
16k    21.3 MiB/s 19.0 MiB/s 22.4 MiB/s 17.0 MiB/s
32k    21.3 MiB/s 19.0 MiB/s 22.5 MiB/s 16.9 MiB/s
64k    20.7 MiB/s 18.7 MiB/s 22.9 MiB/s 16.9 MiB/s
128k   21.3 MiB/s 18.1 MiB/s 22.7 MiB/s 16.4 MiB/s
256k   21.3 MiB/s 18.4 MiB/s 22.4 MiB/s 16.5 MiB/s
512k   21.6 MiB/s 18.9 MiB/s 22.3 MiB/s 16.8 MiB/s
1M     20.9 MiB/s 19.2 MiB/s 22.4 MiB/s 16.9 MiB/s

For the small block sizes there is almost no disk activity, long pauses with no blinking RED LED's.
I'm begining to wonder if some options in Raspbian have been enabled to extend the life of the RPi SSD.

Raspberry Pi Model B USB disk read results
-----------------------------------------------------------
block             filesystem type
size   -------------------------------------------           
(bytes)ext2       ext3       ext4       vfat
8       1.6 MiB/s  2.0 MiB/s  1.7 MiB/s  1.9 MiB/s
16      3.9 MiB/s  3.5 MiB/s  3.6 MiB/s  3.8 MiB/s
32      6.9 MiB/s  6.7 MiB/s  7.2 MiB/s  6.8 MiB/s
64     10.5 MiB/s 10.4 MiB/s 10.2 MiB/s 10.4 MiB/s
128    18.0 MiB/s 16.5 MiB/s 15.2 MiB/s 17.0 MiB/s
256    23.3 MiB/s 22.6 MiB/s 22.1 MiB/s 22.2 MiB/s
512    23.2 MiB/s 23.2 MiB/s 23.4 MiB/s 21.7 MiB/s
1k     23.6 MiB/s 23.2 MiB/s 23.6 MiB/s 22.0 MiB/s
2k     23.7 MiB/s 23.2 MiB/s 23.6 MiB/s 22.3 MiB/s
4k     23.6 MiB/s 22.9 MiB/s 23.6 MiB/s 23.3 MiB/s
8k     22.6 MiB/s 22.3 MiB/s 23.7 MiB/s 23.7 MiB/s
16k    23.6 MiB/s 23.6 MiB/s 23.7 MiB/s 23.7 MiB/s
32k    22.4 MiB/s 23.6 MiB/s 22.6 MiB/s 23.7 MiB/s
64k    22.5 MiB/s 23.6 MiB/s 22.7 MiB/s 23.7 MiB/s
128k   23.7 MiB/s 22.4 MiB/s 22.8 MiB/s 23.7 MiB/s
256k   23.7 MiB/s 22.5 MiB/s 23.8 MiB/s 23.7 MiB/s
512k   23.7 MiB/s 22.6 MiB/s 23.7 MiB/s 23.7 MiB/s
1M     23.7 MiB/s 22.4 MiB/s 23.7 MiB/s 23.7 MiB/s

USB disk performance check (midrange desktop PC) - dedicated USB port

For comparison with the above Raspberry Pi results , here are desktop PC results:

midrange desktop PC disk write results (dedicated HS USB 2.0 port)
------------------------------------------------------------------
block             filesystem type
size   -------------------------------------------             
(bytes)ext2       ext3       ext4       vfat
8       6.3 MiB/s  3.8 MiB/s  3.9 MiB/s  5.4 MiB/s
16     12.9 MiB/s  7.6 MiB/s  7.8 MiB/s 11.1 MiB/s
32     26.1 MiB/s 15.0 MiB/s 15.9 MiB/s 19.4 MiB/s
64     34.9 MiB/s 21.1 MiB/s 31.7 MiB/s 23.3 MiB/s
128    34.9 MiB/s 21.8 MiB/s 37.7 MiB/s 24.0 MiB/s
256    34.2 MiB/s 22.2 MiB/s 37.5 MiB/s 23.4 MiB/s
512    34.1 MiB/s 22.7 MiB/s 37.3 MiB/s 23.5 MiB/s
1k     34.1 MiB/s 22.8 MiB/s 37.1 MiB/s 24.7 MiB/s
2k     33.8 MiB/s 22.7 MiB/s 37.5 MiB/s 24.5 MiB/s
4k     34.0 MiB/s 22.3 MiB/s 37.2 MiB/s 24.4 MiB/s
8k     34.1 MiB/s 22.7 MiB/s 37.4 MiB/s 24.9 MiB/s
16k    35.1 MiB/s 22.9 MiB/s 37.5 MiB/s 23.7 MiB/s
32k    36.0 MiB/s 22.7 MiB/s 37.5 MiB/s 25.4 MiB/s
64k    35.4 MiB/s 23.5 MiB/s 37.6 MiB/s 24.8 MiB/s
128k   35.3 MiB/s 23.1 MiB/s 37.2 MiB/s 24.4 MiB/s
256k   35.6 MiB/s 23.0 MiB/s 37.6 MiB/s 25.5 MiB/s
512k   35.9 MiB/s 23.3 MiB/s 37.6 MiB/s 25.2 MiB/s
1M     35.9 MiB/s 22.7 MiB/s 37.6 MiB/s 25.2 MiB/s

For High Speed USB 2.0 the maximum data rate is about 40MB/sec (38.1MiB/sec) None of the tested filesystems hit this but ext4 did come closest, but not on the Raspberry Pi unfortunately.

('lsusb -t' does shows 480M, which in theory would correspond to 57.2MiB/sec, but there protocol overheads within USB. The maximum should be 53.248 MB/s, but this appears to be deliberately limited to around 30-42MB/sec to maintain interoperability with USB stacks in OS'es over throughput speed).

midrange desktop PC disk read results (dedicated HS USB 2.0 port)
-----------------------------------------------------------------
block             filesystem type
size   -------------------------------------------            
(bytes)ext2       ext3       ext4       vfat
8      18.4 MiB/s 16.8 MiB/s 18.4 MiB/s 18.6 MiB/s
16     32.5 MiB/s 29.3 MiB/s 36.6 MiB/s 35.0 MiB/s
32     32.5 MiB/s 29.0 MiB/s 35.9 MiB/s 34.5 MiB/s
64     33.6 MiB/s 30.4 MiB/s 36.2 MiB/s 35.6 MiB/s
128    33.3 MiB/s 29.9 MiB/s 36.0 MiB/s 35.0 MiB/s
256    32.7 MiB/s 30.3 MiB/s 36.1 MiB/s 34.8 MiB/s
512    33.4 MiB/s 29.9 MiB/s 36.0 MiB/s 35.0 MiB/s
1k     33.5 MiB/s 30.2 MiB/s 36.2 MiB/s 35.9 MiB/s
2k     33.7 MiB/s 30.7 MiB/s 36.4 MiB/s 34.7 MiB/s
4k     34.0 MiB/s 30.5 MiB/s 36.1 MiB/s 35.9 MiB/s
8k     34.0 MiB/s 30.8 MiB/s 36.4 MiB/s 35.4 MiB/s
16k    34.0 MiB/s 30.9 MiB/s 36.4 MiB/s 35.5 MiB/s
32k    34.0 MiB/s 30.7 MiB/s 36.5 MiB/s 35.2 MiB/s
64k    33.7 MiB/s 30.4 MiB/s 36.4 MiB/s 35.2 MiB/s
128k   33.5 MiB/s 30.7 MiB/s 36.4 MiB/s 36.0 MiB/s
256k   33.4 MiB/s 30.5 MiB/s 36.4 MiB/s 34.8 MiB/s
512k   33.5 MiB/s 30.5 MiB/s 36.1 MiB/s 35.8 MiB/s
1M     33.2 MiB/s 30.5 MiB/s 36.5 MiB/s 35.7 MiB/s


I really wonder what the USB performance is for a Model A, which does not have an internal 3 port USB hub inside with a USB NIC connected to one of the ports. For all of the tests above there was basically no network traffic to/from the RPi, and even with that the performance of the USB  is not all that great. But even so it does appear that USB is the fastest way to get data into and out of the Raspberry Pi.

Internal disk performance check (midrange desktop PC)

I reconnected the same 2TB disk to a dedicated 1.5Gbit/sec eSATA port on the back of the desktop PC just to confirm that USB was in fact the bottleneck for data transfers. And to verify that there were no problems with the hard disk that I used.

midrange desktop PC disk write results (1.5 Gbit/sec eSATA port)
------------------------------------------------------------------
block             filesystem type
size   -------------------------------------------            
(bytes)ext2       ext3       ext4       vfat
8       7.2 MiB/s  4.2 MiB/s  4.2 MiB/s  6.4 MiB/s
16     14.6 MiB/s  8.4 MiB/s  8.6 MiB/s 12.3 MiB/s
32     28.5 MiB/s 16.2 MiB/s 16.9 MiB/s 22.0 MiB/s
64     55.9 MiB/s 29.2 MiB/s 34.3 MiB/s 35.5 MiB/s
128    72.1 MiB/s 53.7 MiB/s 61.8 MiB/s 47.8 MiB/s
256    69.4 MiB/s 64.6 MiB/s 59.4 MiB/s 52.4 MiB/s
512    68.3 MiB/s 63.2 MiB/s 58.7 MiB/s 52.7 MiB/s
1k     66.9 MiB/s 62.1 MiB/s 58.4 MiB/s 54.1 MiB/s
2k     66.2 MiB/s 61.4 MiB/s 58.7 MiB/s 54.1 MiB/s
4k     64.8 MiB/s 60.7 MiB/s 58.1 MiB/s 54.1 MiB/s
8k     64.3 MiB/s 60.2 MiB/s 57.3 MiB/s 53.5 MiB/s
16k    64.5 MiB/s 60.6 MiB/s 57.2 MiB/s 52.5 MiB/s
32k    63.2 MiB/s 59.7 MiB/s 56.9 MiB/s 55.4 MiB/s
64k    63.4 MiB/s 60.7 MiB/s 56.8 MiB/s 53.3 MiB/s
128k   62.8 MiB/s 59.2 MiB/s 56.6 MiB/s 53.0 MiB/s
256k   62.6 MiB/s 59.6 MiB/s 56.4 MiB/s 53.1 MiB/s
512k   62.1 MiB/s 58.7 MiB/s 55.3 MiB/s 52.2 MiB/s
1M     61.6 MiB/s 58.3 MiB/s 53.9 MiB/s 52.3 MiB/s



midrange desktop PC disk read results (1.5 Gbit/sec eSATA port)
-----------------------------------------------------------------
block             filesystem type
size   -------------------------------------------           
(bytes)ext2       ext3       ext4       vfat
8      18.7MiB/s  18.6MiB/s  18.5MiB/s  18.5MiB/s
16     36.4MiB/s  36.4MiB/s  36.8MiB/s  36.6MiB/s
32     71.2MiB/s  70.1MiB/s  72.5MiB/s  70.0MiB/s
64    117.3MiB/s 110.6MiB/s  98.2MiB/s  82.3MiB/s
128   116.3MiB/s 111.6MiB/s  98.2MiB/s  82.8MiB/s
256   117.3Mib/s 110.6MiB/s  98.2MiB/s  81.9MiB/s
512   117.3Mib/s 110.6MiB/s  99.2MiB/s  81.3MiB/s
1k    116.3MiB/s 109.7MiB/s  98.2MiB/s  81.3MiB/s
2k    118.3MiB/s 108.7MiB/s  97.3MiB/s  81.3MiB/s
4k    117.3Mib/s 108.7MiB/s  96.3MiB/s  81.3MiB/s
8k    117.3Mib/s 108.7MiB/s  95.2MiB/s  81.3MiB/s
16k   118.3MiB/s 108.7MiB/s  95.4MiB/s  81.3MiB/s
32k   118.3MiB/s 108.7MiB/s  95.4MiB/s  81.3MiB/s
64k   118.3MiB/s 108.7MiB/s  95.3MiB/s  81.3MiB/s
128k  118.3MiB/s 108.7MiB/s  95.3MiB/s  81.0MiB/s
256k  118.3MiB/s 108.7MiB/s  95.2MiB/s  81.4MiB/s
512k  118.3MiB/s 108.7MiB/s  94.7MiB/s  81.3MiB/s
1M    118.3MiB/s 107.8MiB/s  94.2MiB/s  81.3MiB/s


All the results say that the HDD was functioning within expected parameters. So all transfer limits (64+ bytes) were due to USB protocol limitation or the 3 port USB hub internal to the Raspberry Pi.