Difference between revisions of "drive speed tests"
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− | [[Category:Engineering]] | + | [[Category: Engineering]] |
− | [[Category:Drives_and_Filesystems]] | + | [[Category: Drives_and_Filesystems]] |
+ | [[Category: Performance]] | ||
== drive speed test results -- trivial benchmarks == | == drive speed test results -- trivial benchmarks == | ||
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{| border="1" | {| border="1" | ||
|- | |- | ||
− | !write speed in MB/s !! read speed in MB/s !! drive name | + | !write speed in MB/s !! read speed in MB/s !! drive name / model !! USB ID !! Notes |
|- | |- | ||
− | | | + | | 6.36 || 19.88 || Pie Digital, Inc. PieKey 4GB || 22a6:ffff || This was from a Flash drive I worked on -- I set the PID! Pretty decent specs. |
|- | |- | ||
− | | | + | | 9.87 || 17.71 || Pie Digital, Inc. PieKey 1GB early prototype || 04fe:0006 || |
|- | |- | ||
− | | | + | | 38.88 || 81.37 || Corsair Voyager Slider 32GB USB3 Model CMFSL3-32GB || 1b1c:1a06 || |
|- | |- | ||
− | | | + | | 35.99 || 68.42 || Kingston Technology 32GB USB3|| 0951:168e || test-drive-speed V2 |
|- | |- | ||
− | | | + | | 4.34 || 22.63 || SanDisk Cruzer Fit 16GB || 0781:5571 || This USB flash drive is a tiny, little nub, hardly bigger than the USB plug itself. |
|- | |- | ||
− | | | + | | 4.20 || 22.62 || SanDisk Cruzer Facet 8GB || 0781:5576 || |
|- | |- | ||
− | | | + | | 4.01 || 18.10 || SanDisk Cruzer 16GB SDCZ36-016G || 0781:5530 || |
|- | |- | ||
− | | | + | | 4.32 || 18.67 || Lexar Media 4GB || 05dc:a768 || |
|- | |- | ||
− | | | + | | 4.01 || 15.45 || Alcor Micro Corp. 2GB || 058f:6387 || This was from a free Jaguar car keyfob schwag. It was kind of crappy. |
|- | |- | ||
− | | | + | | 3.51 || 23.76 || Transcend Information OCZ Diesel 4GB || 1307:0165 || |
|- | |- | ||
− | | | + | | 5.42 || 23.24 || SanDisk Cruzer Orbit 32GB || 0781:557c || |
|- | |- | ||
− | | | + | | 13.64 || 41.91 || Kingston Technology 128GB || 0951:1697 || Tested USB3 device in a USB2 port. |
|- | |- | ||
− | | | + | | 16.24 || 152.78 || Kingston Technology 128GB || 0951:1697 || Tested in USB3 port. Write speed was bad. At first I thought it I made a mistake, so I tested again against a USB3 drive known to be fast. The Kingston was still very slow. |
|- | |- | ||
− | | | + | | 10.27 || 17.50 || OEM 2GB || 13fe:1f00 || Impressive write speed for a cheap USB2 drive. |
|- | |- | ||
− | | | + | | 6.64 || 15.58 || Cisco Linksys Connect Easy Setup Key 1GB / NK2 || 13b1:002e || |
+ | |- | ||
+ | | 44.83 || 78.78 || Seagate Momentus 7200.3 / ST9160411ASG || || Serial Number: 5TG0K2CB Firmware Revision: DE17 | ||
+ | |- | ||
+ | | 28.14 || 120.80 || Transcend 2.5" SATA-2 SSD / TS64GSSD25S-M || || Serial Number: 002538030036 Firmware Revision: V090216 | ||
+ | |- | ||
+ | | 70.98 || 125.97 || OCZ VERTEX-LE SATA-2 SSD || || Serial Number: f0409001b, Firmware Revision: 1.05 | ||
+ | |- | ||
+ | | 73.17 || 166.16 || apocalypse.dreamhost.com || || Run on a shared hosting service. Drive specs unknown. Quite fast for a shared host. | ||
+ | |- | ||
+ | | 115.82 || 534.99 || Amazon EC2 || || 184.72.242.0 Amazon EC2 West Coast server. Write speeds vary drastically. Average of 18 runs. Look at that read speed! | ||
+ | |- | ||
+ | | 131.15 || 269.65 || Amazon EC2 || || 184.72.18.0 Amazon EC2 West Coast server. Write speeds vary drastically. Average of 9 runs. | ||
+ | |- | ||
+ | | 53.00 || 106.97 || Hitachi HTS545050A7E380 through SimpleTech USB3 || 4971:8013 || Firmware Revision: GG2OA7A0 | ||
+ | |- | ||
+ | | 82.52 || 185.64 || SanDisk Corp. Extreme CZ80 USB 3.0 32GB || 0781:5580 || ''Update: SanDisk has a slightly faster drive now, the Extreme CZ80 USB 3.0 32GB.'' So this USB3 flash drive is faster than any of my main system disks in any of my laptops -- hard disk or SSD. This thing is faster than any SSD I have tested (granted, I haven't tested anything designed specifically for speed). But still, this is just a USB3 flash drive. I tested the speed on a few different machines. It seems real. Maybe I'll throw away my main SSD and just boot off this thing -- Note, that I actually suggested this as a design option for an embedded system for a company I once worked for. They all laughed at me, but it totally made sense. Speed was not a concern for us. It was all about cost. We could have reduced our BOM cost for storage by using commodity, cheap USB flash drives instead of the rather niche market, obscure micro-IDE interface at over 4 times the cost of a '''good''' USB flash drive of similar size. Plus we would have eliminated yet another costly connector on our PCB (and the board real estate it took) in exchange for another USB plug. Furthermore, this USB plug was linked to an existing USB with two ports to spare, so it didn't require any additional support hardware. Finally, those obscure micro-IDE connectors and drives were a pain in the ass. The connectors were fragile and the drives had quirky behavior. Come on, nobody bought these things, so they had no market at all and thus very little field testing and feedback from customers. I mean, I gave feedback to complain about the stupid things and the manufacturer was like, "Yeah... well, I'm sorry to hear that. That's too bad, but what are you gonna do? Performance ain't great, but they're the best in this market. Actually, you know, we might drop the entire product line next year. Do you want to buy the remaining stock?"... Meanwhile, in the development period of our product USB Flash drive prices had dropped by half and speeds and density were better than our IDE SSD -- and that was over USB2 through a shared HUB (yeah, those IDE SSDs really sucked). Next time something like this comes up I have to approach the problem differently and present it in a way my audience can understand. | ||
+ | |- | ||
+ | | 98.11 || 189.85 || SanDisk Extreme CZ80 USB 3.0 32GB || 0781:5580 || Super fast! This was a second test of the Extreme CZ80. I used my updated '''test-drive-speed V2''' script and a new Extreme CZ80. This thing is fast. You don't need a benchmark to tell you. You can feel the difference. Serial Number: 03e9a18ef Firmware Revision: ER.24.00 Transport: Serial, ATA8-AST, SATA Rev 2.6, SATA Rev 3.0 | ||
+ | |- | ||
+ | | WRITE || READ || NAME || USBID || COMMENTS | ||
|} | |} | ||
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# | # | ||
# This performs a very simple drive speed test. It measures sustained | # This performs a very simple drive speed test. It measures sustained | ||
− | # write and read speed to a | + | # write and read speed to a 256 MB file. |
# | # | ||
# AUTHOR | # AUTHOR | ||
Line 99: | Line 120: | ||
# http://opensource.org/licenses/isc-license.txt | # http://opensource.org/licenses/isc-license.txt | ||
# | # | ||
− | # Copyright (c) | + | # Copyright (c) 2013, Noah Spurrier <noah@noah.org> |
# | # | ||
# Permission to use, copy, modify, and/or distribute this software for any | # Permission to use, copy, modify, and/or distribute this software for any | ||
Line 115: | Line 136: | ||
# VERSION | # VERSION | ||
# | # | ||
− | # Version | + | # Version 2 |
# | # | ||
− | echo " | + | # For a 128 MB file use BLOCK_COUNT=16 and BLOCK_SIZE=8388608. |
+ | # For a 256 MB file use BLOCK_COUNT=32 and BLOCK_SIZE=8388608. | ||
+ | BLOCK_COUNT=32 | ||
+ | BLOCK_SIZE=8388608 | ||
+ | OUTPUT_FILE="junk.bin" | ||
+ | |||
+ | if [ -d /dev/shm ]; then | ||
+ | echo "= Create source data file in /dev/shm/random.bin =" | ||
+ | SOURCE_DATA=/dev/shm/random.bin | ||
+ | rm -f ${SOURCE_DATA} | ||
+ | dd if=/dev/urandom of=${SOURCE_DATA} bs=${BLOCK_SIZE} count=${BLOCK_COUNT} | ||
+ | else | ||
+ | echo "= WARNING: Using /dev/zero for data. Results may skewed fast. =" | ||
+ | SOURCE_DATA=/dev/zero | ||
+ | fi | ||
+ | |||
+ | sync | ||
+ | echo "uptime: $(uptime)" | ||
PWD=$(pwd) | PWD=$(pwd) | ||
− | echo " | + | echo "current directory: ${PWD}" |
CURRENT_DEV=$(df -hT $(pwd) \ | CURRENT_DEV=$(df -hT $(pwd) \ | ||
− | + | | sed -n -e 's/^\(\/dev\/[^[:space:]]\+\).*/\1/p') | |
+ | |||
if [ "${CURRENT_DEV}" = "" ]; then | if [ "${CURRENT_DEV}" = "" ]; then | ||
− | + | echo "WARNING: Did not find device associated with current directory." | |
else | else | ||
− | + | echo "mount device: ${CURRENT_DEV}" | |
− | + | echo "drive mount options: $(grep ${CURRENT_DEV} /etc/mtab)" | |
− | + | if grep ${CURRENT_DEV} /etc/mtab | grep -iq sync; then | |
− | + | echo " WARNING: sync option will effect write speed tests." | |
− | + | fi | |
− | + | if echo ${CURRENT_DEV} | grep -q /dev/md; then | |
− | + | echo " This device is a sofware RAID configured as follows:" | |
− | + | echo -en " " | |
− | + | egrep 'md[0-9]+' /proc/mdstat | |
− | + | CURRENT_DEV=$(egrep 'md[0-9]+' /proc/mdstat \ | |
− | + | |sed -n -e 's/.*[[:space:]]\([a-z]*[0-9]*\)\[.\]$/\1/p') | |
− | + | CURRENT_DEV="/dev/${CURRENT_DEV}" | |
− | + | echo " Drive info will be taken from last device in the array." | |
+ | fi | ||
+ | # Try `hdparm` otherwise try `lsusb`. | ||
+ | if ! DRIVE_INFO=$(hdparm -I ${CURRENT_DEV} | sed -n -e '/^$/d' \ | ||
+ | -e '0,/Standards:/p' | sed -n -e '$!p'); then | ||
+ | DRIVE_INFO=$(lsusb) | ||
+ | fi | ||
+ | DRIVE_INFO=$(echo ${DRIVE_INFO}) | ||
+ | echo "drive info: ${DRIVE_INFO}" | ||
fi | fi | ||
+ | |||
+ | echo | ||
echo "Running test three times..." | echo "Running test three times..." | ||
+ | |||
for n in 1 2 3; do | for n in 1 2 3; do | ||
− | + | echo -n "test ${n}: " | |
− | + | sync | |
− | + | dd if=${SOURCE_DATA} of=${OUTPUT_FILE} oflag=dsync conv=fdatasync \ | |
− | + | bs=${BLOCK_SIZE} count=${BLOCK_COUNT} 2>&1|grep "copied"|cut -f1,6 -d" " \ | |
− | + | |awk '{printf("write: %7.2f MB/s, ",$1/$2/(1024*1024))}' | |
− | + | sync | |
− | + | if [ ! -e /dev/zero ]; then | |
− | + | rm ${SOURCE_DATA} | |
− | + | fi | |
+ | dd if=${OUTPUT_FILE} iflag=direct conv=fdatasync of=${SOURCE_DATA} \ | ||
+ | bs=${BLOCK_SIZE} count=${BLOCK_COUNT} 2>&1|grep "copied"|cut -f1,6 -d" " \ | ||
+ | |awk '{printf("read: %7.2f MB/s\n",$1/$2/(1024*1024))}' | ||
+ | rm junk.bin | ||
done | done | ||
− | # vim:set sr et ts=4 sw=4 | + | |
+ | if [ -e /dev/shm/random.bin ]; then | ||
+ | rm ${SOURCE_DATA} | ||
+ | fi | ||
+ | |||
+ | # vim:set ft=sh sr et ts=4 sw=4: // See Vim, :help 'modeline' | ||
</pre> | </pre> | ||
Latest revision as of 15:08, 19 August 2015
Contents
drive speed test results -- trivial benchmarks
Raw read and write speed may not the best benchmark, but it's a start. For USB Flash drives this is usually the benchmark that I care about the most since I usually use USB Flash drives for moving large files around.
write speed in MB/s | read speed in MB/s | drive name / model | USB ID | Notes |
---|---|---|---|---|
6.36 | 19.88 | Pie Digital, Inc. PieKey 4GB | 22a6:ffff | This was from a Flash drive I worked on -- I set the PID! Pretty decent specs. |
9.87 | 17.71 | Pie Digital, Inc. PieKey 1GB early prototype | 04fe:0006 | |
38.88 | 81.37 | Corsair Voyager Slider 32GB USB3 Model CMFSL3-32GB | 1b1c:1a06 | |
35.99 | 68.42 | Kingston Technology 32GB USB3 | 0951:168e | test-drive-speed V2 |
4.34 | 22.63 | SanDisk Cruzer Fit 16GB | 0781:5571 | This USB flash drive is a tiny, little nub, hardly bigger than the USB plug itself. |
4.20 | 22.62 | SanDisk Cruzer Facet 8GB | 0781:5576 | |
4.01 | 18.10 | SanDisk Cruzer 16GB SDCZ36-016G | 0781:5530 | |
4.32 | 18.67 | Lexar Media 4GB | 05dc:a768 | |
4.01 | 15.45 | Alcor Micro Corp. 2GB | 058f:6387 | This was from a free Jaguar car keyfob schwag. It was kind of crappy. |
3.51 | 23.76 | Transcend Information OCZ Diesel 4GB | 1307:0165 | |
5.42 | 23.24 | SanDisk Cruzer Orbit 32GB | 0781:557c | |
13.64 | 41.91 | Kingston Technology 128GB | 0951:1697 | Tested USB3 device in a USB2 port. |
16.24 | 152.78 | Kingston Technology 128GB | 0951:1697 | Tested in USB3 port. Write speed was bad. At first I thought it I made a mistake, so I tested again against a USB3 drive known to be fast. The Kingston was still very slow. |
10.27 | 17.50 | OEM 2GB | 13fe:1f00 | Impressive write speed for a cheap USB2 drive. |
6.64 | 15.58 | Cisco Linksys Connect Easy Setup Key 1GB / NK2 | 13b1:002e | |
44.83 | 78.78 | Seagate Momentus 7200.3 / ST9160411ASG | Serial Number: 5TG0K2CB Firmware Revision: DE17 | |
28.14 | 120.80 | Transcend 2.5" SATA-2 SSD / TS64GSSD25S-M | Serial Number: 002538030036 Firmware Revision: V090216 | |
70.98 | 125.97 | OCZ VERTEX-LE SATA-2 SSD | Serial Number: f0409001b, Firmware Revision: 1.05 | |
73.17 | 166.16 | apocalypse.dreamhost.com | Run on a shared hosting service. Drive specs unknown. Quite fast for a shared host. | |
115.82 | 534.99 | Amazon EC2 | 184.72.242.0 Amazon EC2 West Coast server. Write speeds vary drastically. Average of 18 runs. Look at that read speed! | |
131.15 | 269.65 | Amazon EC2 | 184.72.18.0 Amazon EC2 West Coast server. Write speeds vary drastically. Average of 9 runs. | |
53.00 | 106.97 | Hitachi HTS545050A7E380 through SimpleTech USB3 | 4971:8013 | Firmware Revision: GG2OA7A0 |
82.52 | 185.64 | SanDisk Corp. Extreme CZ80 USB 3.0 32GB | 0781:5580 | Update: SanDisk has a slightly faster drive now, the Extreme CZ80 USB 3.0 32GB. So this USB3 flash drive is faster than any of my main system disks in any of my laptops -- hard disk or SSD. This thing is faster than any SSD I have tested (granted, I haven't tested anything designed specifically for speed). But still, this is just a USB3 flash drive. I tested the speed on a few different machines. It seems real. Maybe I'll throw away my main SSD and just boot off this thing -- Note, that I actually suggested this as a design option for an embedded system for a company I once worked for. They all laughed at me, but it totally made sense. Speed was not a concern for us. It was all about cost. We could have reduced our BOM cost for storage by using commodity, cheap USB flash drives instead of the rather niche market, obscure micro-IDE interface at over 4 times the cost of a good USB flash drive of similar size. Plus we would have eliminated yet another costly connector on our PCB (and the board real estate it took) in exchange for another USB plug. Furthermore, this USB plug was linked to an existing USB with two ports to spare, so it didn't require any additional support hardware. Finally, those obscure micro-IDE connectors and drives were a pain in the ass. The connectors were fragile and the drives had quirky behavior. Come on, nobody bought these things, so they had no market at all and thus very little field testing and feedback from customers. I mean, I gave feedback to complain about the stupid things and the manufacturer was like, "Yeah... well, I'm sorry to hear that. That's too bad, but what are you gonna do? Performance ain't great, but they're the best in this market. Actually, you know, we might drop the entire product line next year. Do you want to buy the remaining stock?"... Meanwhile, in the development period of our product USB Flash drive prices had dropped by half and speeds and density were better than our IDE SSD -- and that was over USB2 through a shared HUB (yeah, those IDE SSDs really sucked). Next time something like this comes up I have to approach the problem differently and present it in a way my audience can understand. |
98.11 | 189.85 | SanDisk Extreme CZ80 USB 3.0 32GB | 0781:5580 | Super fast! This was a second test of the Extreme CZ80. I used my updated test-drive-speed V2 script and a new Extreme CZ80. This thing is fast. You don't need a benchmark to tell you. You can feel the difference. Serial Number: 03e9a18ef Firmware Revision: ER.24.00 Transport: Serial, ATA8-AST, SATA Rev 2.6, SATA Rev 3.0 |
WRITE | READ | NAME | USBID | COMMENTS |
Do not mount with sync option
The first test run shows that write performance is over 12 times slower when the drive is mounted with the sync option versus the second test without the sync option. The other options have little effect. These tests were run on a USB flash drive.
first test
/dev/sdb1 on /media/usb0 type vfat (rw,noexec,nodev,sync,noatime,nodiratime) Running test three times... test 1: write: 0.34 MB/s, read: 18.67 MB/s test 2: write: 0.34 MB/s, read: 18.61 MB/s test 3: write: 0.34 MB/s, read: 18.29 MB/s
second test
/dev/sdb1 on /media/usb0 type vfat (rw) Running test three times... test 1: write: 4.32 MB/s, read: 18.51 MB/s test 2: write: 4.32 MB/s, read: 18.51 MB/s test 3: write: 4.31 MB/s, read: 18.46 MB/s
trivial benchmark tool
You can use `dd` to measure sustained drive throughput if you do it right. You want to bypass any cache and buffering in the I/O path. This is not hard, but it is uncommon enough that it can be difficult to find documentation on the correct options to use.
It is unclear if this will also bypass RAID controller cache. It almost certainly will not bypass the cache on the drive itself. You would need to activate additional option via `hdparm` if your drive offers them. I considered this a little too invasive and I wasn't sure if the options would be the same for every drive. Plus I figured that the drive controller cache is not really an optional component of the drive, so there is no reason to take it out of the equation; although, it does make it more difficult to interpret read-speed tests.
the most trivial drive benchmark tool
alias test-drive-speed='dd if=/dev/zero of=test_data.bin oflag=dsync conv=fdatasync bs=8388608 count=16 2>&1 | grep "bytes" | cut -f1,6 -d" " | awk '\''{printf ("write-speed: %7.2f MB/s, ", $1 / $2 / (1024*1024))}'\'' && dd if=test_data.bin iflag=direct conv=fdatasync of=/dev/null bs=8388608 count=16 2>&1 | grep "copied" | cut -f1,6 -d" " | awk '\''{printf ("read-speed: %7.2f MB/s\n", $1 / $2 / (1024*1024))}'\'''
slightly less trivial benchmark tool
#!/bin/bash # # test-drive-speed # # DESCRIPTION # # This performs a very simple drive speed test. It measures sustained # write and read speed to a 256 MB file. # # AUTHOR # # Noah Spurrier <noah@noah.org> # # LICENSE # # This license is OSI and FSF approved as GPL-compatible. # This license identical to the ISC License and is registered with and # approved by the Open Source Initiative. For more information vist: # http://opensource.org/licenses/isc-license.txt # # Copyright (c) 2013, Noah Spurrier <noah@noah.org> # # Permission to use, copy, modify, and/or distribute this software for any # purpose with or without fee is hereby granted, provided that the above # copyright notice and this permission notice appear in all copies. # # THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF # OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. # # VERSION # # Version 2 # # For a 128 MB file use BLOCK_COUNT=16 and BLOCK_SIZE=8388608. # For a 256 MB file use BLOCK_COUNT=32 and BLOCK_SIZE=8388608. BLOCK_COUNT=32 BLOCK_SIZE=8388608 OUTPUT_FILE="junk.bin" if [ -d /dev/shm ]; then echo "= Create source data file in /dev/shm/random.bin =" SOURCE_DATA=/dev/shm/random.bin rm -f ${SOURCE_DATA} dd if=/dev/urandom of=${SOURCE_DATA} bs=${BLOCK_SIZE} count=${BLOCK_COUNT} else echo "= WARNING: Using /dev/zero for data. Results may skewed fast. =" SOURCE_DATA=/dev/zero fi sync echo "uptime: $(uptime)" PWD=$(pwd) echo "current directory: ${PWD}" CURRENT_DEV=$(df -hT $(pwd) \ | sed -n -e 's/^\(\/dev\/[^[:space:]]\+\).*/\1/p') if [ "${CURRENT_DEV}" = "" ]; then echo "WARNING: Did not find device associated with current directory." else echo "mount device: ${CURRENT_DEV}" echo "drive mount options: $(grep ${CURRENT_DEV} /etc/mtab)" if grep ${CURRENT_DEV} /etc/mtab | grep -iq sync; then echo " WARNING: sync option will effect write speed tests." fi if echo ${CURRENT_DEV} | grep -q /dev/md; then echo " This device is a sofware RAID configured as follows:" echo -en " " egrep 'md[0-9]+' /proc/mdstat CURRENT_DEV=$(egrep 'md[0-9]+' /proc/mdstat \ |sed -n -e 's/.*[[:space:]]\([a-z]*[0-9]*\)\[.\]$/\1/p') CURRENT_DEV="/dev/${CURRENT_DEV}" echo " Drive info will be taken from last device in the array." fi # Try `hdparm` otherwise try `lsusb`. if ! DRIVE_INFO=$(hdparm -I ${CURRENT_DEV} | sed -n -e '/^$/d' \ -e '0,/Standards:/p' | sed -n -e '$!p'); then DRIVE_INFO=$(lsusb) fi DRIVE_INFO=$(echo ${DRIVE_INFO}) echo "drive info: ${DRIVE_INFO}" fi echo echo "Running test three times..." for n in 1 2 3; do echo -n "test ${n}: " sync dd if=${SOURCE_DATA} of=${OUTPUT_FILE} oflag=dsync conv=fdatasync \ bs=${BLOCK_SIZE} count=${BLOCK_COUNT} 2>&1|grep "copied"|cut -f1,6 -d" " \ |awk '{printf("write: %7.2f MB/s, ",$1/$2/(1024*1024))}' sync if [ ! -e /dev/zero ]; then rm ${SOURCE_DATA} fi dd if=${OUTPUT_FILE} iflag=direct conv=fdatasync of=${SOURCE_DATA} \ bs=${BLOCK_SIZE} count=${BLOCK_COUNT} 2>&1|grep "copied"|cut -f1,6 -d" " \ |awk '{printf("read: %7.2f MB/s\n",$1/$2/(1024*1024))}' rm junk.bin done if [ -e /dev/shm/random.bin ]; then rm ${SOURCE_DATA} fi # vim:set ft=sh sr et ts=4 sw=4: // See Vim, :help 'modeline'