Date: Mon, 14 Aug 2006 12:43:26 +0200 From: Marc van Woerkom <marc.vanwoerkom@FernUni-Hagen.de> To: Intron <mag@intron.ac> Cc: freebsd-usb@freebsd.org Subject: Re: SD card speed Message-ID: <44E053CE.4090304@fernuni-hagen.de> In-Reply-To: <courier.44E01EDB.00000942@intron.ac> References: <44DF8308.9080700@fernuni-hagen.de> <6.2.3.4.0.20060813170759.12be7730@64.7.153.2> <44E00CFE.5090806@fernuni-hagen.de> <courier.44E01EDB.00000942@intron.ac>
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Intron wrote: > Have you tested your card reader on Microsoft Windows? > FreeBSD's FAT module probably isn't optimized enough. > No, but what I just tried again,after I formatted the SD card under Windows. Guess what happened: tty da2 cpu tin tout KB/t tps MB/s us ni sy in id 0 64 4.00 483 1.89 10 0 17 13 60 0 161 4.00 486 1.90 16 0 13 12 59 0 43 4.00 477 1.86 9 0 14 8 70 0 65 4.00 422 1.65 8 0 15 9 69 0 78 4.00 486 1.90 5 0 11 13 71 0 43 4.00 485 1.89 4 0 5 8 83 0 121 4.00 474 1.85 10 0 14 9 67 0 43 4.00 486 1.90 8 0 16 11 65 0 43 4.00 483 1.89 16 0 6 9 69 0 43 4.00 396 1.55 7 0 16 9 69 0 65 4.00 484 1.89 9 0 14 10 67 0 43 4.00 482 1.88 7 0 16 13 63 0 43 4.00 485 1.89 5 0 14 12 69 0 43 4.00 318 1.24 6 0 9 13 71 136 43 4.00 482 1.88 9 0 16 6 69 Thus the crucial factor is the formatting! What the heck is the difference between a formatting done with sysinstall's fdisk and Windows XP's format? fdisk reports [root@hokage /mnt]# 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 11 (0x0b),(DOS or Windows 95 with 32 bit FAT) 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> Is there really a difference? In the old times, I am talking Apple ][ 140kb floppies, the so called interleave of the sectors made a difference, thus how the logical sector numbers were assigned to the physical sector numbers. A different interleave factor made it that once a sector was read the next logical sector was beneath the read head, so it was quicker. Maybe there is some sorting order important as well in this case? Any idea how I can solve this puzzle? I am bit frustrated, if I have to format under Windows to get a decent speed. Regards, Marc
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