Date: Mon, 14 Aug 2006 07:41:18 +0200 From: Marc van Woerkom <marc.vanwoerkom@FernUni-Hagen.de> To: Mike Tancsa <mike@sentex.net> Cc: freebsd-usb@freebsd.org Subject: Re: [Fwd: SD card speed] Message-ID: <44E00CFE.5090806@fernuni-hagen.de> In-Reply-To: <6.2.3.4.0.20060813170759.12be7730@64.7.153.2> References: <44DF8308.9080700@fernuni-hagen.de> <6.2.3.4.0.20060813170759.12be7730@64.7.153.2>
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I did some more tests.
Using smaller blocksizes (newfs_msdosfs -b 4096) yields even slower write
transfer rates. It looks like there are only 7 transfers per seconds,
thus if
the blocksize is smaller, less data is shoveled over.
tty da2 cpu
tin tout KB/t tps MB/s us ni sy in id
0 65 4.00 7 0.03 14 0 6 2 78
0 181 4.00 7 0.03 11 0 7 2 80
0 89 4.00 7 0.03 13 0 8 4 75
0 69 4.00 7 0.03 9 0 9 2 80
0 76 4.00 6 0.02 16 0 4 4 77
0 71 4.00 7 0.03 12 0 10 3 75
0 132 4.00 7 0.03 6 0 16 3 75
0 76 4.00 7 0.03 34 0 8 4 54
0 78 4.00 7 0.03 8 0 5 2 86
0 152 4.00 7 0.03 14 0 5 1 80
0 87 4.00 6 0.02 12 0 6 1 81
0 80 4.00 7 0.03 9 0 7 3 80
It doesn't seem to matter if it is FAT or FAT32.
However if I format the SD card as UFS2 system, the card is fast:
[root@hokage /]# fdisk /dev/da2
******* Working on device /dev/da2 *******
parameters extracted from in-core disklabel are:
cylinders=472 heads=64 sectors/track=32 (2048 blks/cyl)
parameters to be used for BIOS calculations are:
cylinders=472 heads=64 sectors/track=32 (2048 blks/cyl)
Media sector size is 512
Warning: BIOS sector numbering starts with sector 1
Information from DOS bootblock is:
The data for partition 1 is:
sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD)
start 32, size 966624 (471 Meg), flag 80 (active)
beg: cyl 0/ head 1/ sector 1;
end: cyl 471/ head 63/ sector 32
The data for partition 2 is:
<UNUSED>
The data for partition 3 is:
<UNUSED>
The data for partition 4 is:
<UNUSED>
tty da2 cpu
tin tout KB/t tps MB/s us ni sy in id
27 55 1.45 1 0.00 12 0 7 2 79
0 162 128.00 20 2.50 8 0 9 4 80
0 70 128.00 23 2.87 5 0 9 3 83
0 66 128.00 21 2.62 12 0 7 1 80
0 44 128.00 24 3.00 9 0 8 1 83
0 72 128.00 22 2.75 7 0 5 1 87
0 127 128.00 23 2.87 12 0 13 3 71
0 66 128.00 23 2.87 5 0 7 4 84
0 81 128.00 23 2.87 17 0 8 4 71
0 66 128.00 23 2.87 7 0 9 4 80
0 70 128.00 22 2.75 12 0 11 3 74
0 90 128.00 23 2.87 10 0 8 2 80
136 81 128.00 20 2.50 9 0 9 2 80
Thus the slowdown seems to be related to using a FAT filesystem on
that SD card.
Last thing I have to test is what happens, if I partition/format that
SD card under Windows.
Regards,
Marc
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