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eronde n00b
Joined: 25 Dec 2004 Posts: 73 Location: The Netherlands
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Posted: Fri Feb 22, 2013 7:53 pm Post subject: usb2 storage: Speed issue |
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Hello,
I've a problem with correct writing on an usb device and I've really no idea how to solve it.
Problem:
When I write files to an usb2 device the first 2.2gigs goes with an average speed of 60mb/s, but after that it slows down to a speed of 5mb/s. I've already to format the drive to ntfs/ext4/xfs, but with the same result.
I've also tried to build the xhci_hcd module as Module and as buildin kernel module.
Adding pci=routeirq doesn't works also.
What can I do:
Kernel: gentoo-source-3.7.7
Code: |
lsmod
Module Size Used by
fuse 56670 2
nfsd 67759 11
lockd 52874 1 nfsd
sunrpc 144124 19 nfsd,lockd
hwmon_vid 1957 0
ipt_REJECT 2034 0
xt_limit 1671 0
xt_tcpudp 2240 0
xt_conntrack 2746 0
ipv6 225886 52
iptable_filter 1305 0
iptable_mangle 1401 0
iptable_nat 2391 0
nf_conntrack_ipv4 10872 1
nf_defrag_ipv4 1172 1 nf_conntrack_ipv4
nf_nat_ipv4 3065 1 iptable_nat
nf_nat 11261 2 nf_nat_ipv4,iptable_nat
nf_conntrack 52352 5 nf_nat,nf_nat_ipv4,xt_conntrack,iptable_nat,nf_conntrack_ipv4
ip_tables 13587 3 iptable_filter,iptable_mangle,iptable_nat
x_tables 14193 7 ip_tables,xt_tcpudp,xt_limit,xt_conntrack,iptable_filter,ipt_REJECT,iptable_mangle
usbhid 22721 0
acpi_cpufreq 6303 1
mperf 1068 1 acpi_cpufreq
pata_acpi 3060 0
usb_storage 51396 1
snd_hda_codec_realtek 50390 1
ohci_hcd 24917 0
freq_table 2147 1 acpi_cpufreq
radeon 716809 2
i2c_algo_bit 4472 1 radeon
drm_kms_helper 21207 1 radeon
snd_hda_intel 21861 5
kvm 209721 0
ttm 52609 1 radeon
snd_hda_codec 65046 2 snd_hda_codec_realtek,snd_hda_intel
snd_hwdep 5127 1 snd_hda_codec
r8169 46293 0
drm 187885 4 ttm,drm_kms_helper,radeon
asus_atk0110 7078 0
snd_pcm 58115 3 snd_hda_codec,snd_hda_intel
mii 3412 1 r8169
pata_via 8285 0
snd_page_alloc 6155 2 snd_pcm,snd_hda_intel
backlight 3761 1 radeon
snd_timer 15472 2 snd_pcm
i2c_piix4 7520 0
snd 47811 14 snd_hda_codec_realtek,snd_hwdep,snd_timer,snd_pcm,snd_hda_codec,snd_hda_intel
processor 25996 1 acpi_cpufreq
pata_atiixp 4420 0
ehci_hcd 44378 0
i2c_core 16325 5 drm,i2c_piix4,drm_kms_helper,i2c_algo_bit,radeon
k10temp 2675 0
thermal_sys 12945 1 processor
button 4438 0
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NeddySeagoon Administrator
Joined: 05 Jul 2003 Posts: 54216 Location: 56N 3W
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Posted: Fri Feb 22, 2013 8:08 pm Post subject: |
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eronde,
You cannot write at 60Mb/sec over USB2. The bus cannot carry useful data even close to that speed.
The 60Mb sec for 2.2G comes from filling your RAM with 'dirty' buffers being queued for writing.
The 5Mb/sec is what the device is really capable of and is what you see once there is no more space in RAM for buffers.
You don't say what the device is but it sounds like a flash memory stick. _________________ Regards,
NeddySeagoon
Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail. |
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eronde n00b
Joined: 25 Dec 2004 Posts: 73 Location: The Netherlands
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Posted: Sat Feb 23, 2013 2:04 pm Post subject: |
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Thnx for the replay.
It's a verbatim 64gig.
I also dit a dd:
Code: |
dd count=1k bs=1M if=/dev/zero of=/mnt/cdrom/test.img
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 6.8789 s, 156 MB/s
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With dd it writes with 3.8mb/s.
I did the same test with pv and the result are almost the same.
Is this a correct speed to write on a flash drive? |
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NeddySeagoon Administrator
Joined: 05 Jul 2003 Posts: 54216 Location: 56N 3W
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Posted: Sat Feb 23, 2013 3:30 pm Post subject: |
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eronde,
Speed comes at a price. ... Actually two prices.
High speed flash memory cots more
High speed flash memory needs more power.
A USB device is limited by the power the USB bus can supply to 2.5w (500mA at 5v)
My new SSD, needs 10w. The difference between a USB flash stick and a SSD is the power available and how much you want to pay for speed.
5Mb/sec continuous write speed is OK for a USB2 stick. _________________ Regards,
NeddySeagoon
Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail. |
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eronde n00b
Joined: 25 Dec 2004 Posts: 73 Location: The Netherlands
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Posted: Sat Feb 23, 2013 3:38 pm Post subject: |
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NeddySeagoon,
Thnx for the info, have a nice day. |
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