There seems to be a huge variation in write speed between brands/models. Without an LED it's guesswork. Might have to stay away from micro-SDs.
Here are some rough & ready stats on read speeeds. As a rule of thumb write speeds are generally
less than half the read speed.
Whilst these do not effect USB/SD live running they impact boot up speed and save time.
sh-4.1# hdparm -t /dev/sdb1 (USB2 STICK - FAT32 PARTITION)
/dev/sdb1:
Timing buffered disk reads: 26 MB in 3.78 seconds = 7036 kB/s
sh-4.1# hdparm -t /dev/sdb2
-------------------------------------------------------------------
/dev/sdb2: (SAME USB2 STICK - EXT4 PARTITION)
Timing buffered disk reads: 63 MB in 3.04 seconds = 21194 kB/s
sh-4.1# hdparm -t /dev/sda1
-------------------------------------------------------------------
/dev/sda1: (NTFS HDD - WD 7200rpm SATA-2)
Timing buffered disk reads: 146 MB in 3.00 seconds = 49717 kB/s
sh-4.1#
-------------------------------------------------------------------
sh-4.1# hdparm -t /dev/sde1 (16MEG FAT32 SmartmediaCard)
/dev/sde1:
Timing buffered disk reads: 13 MB in 3.01 seconds = 4412 kB/s
sh-4.1#
-------------------------------------------------------------------
Given the (not surprising) speed advantage and robustness of EXT4 it actually makes sense to
place both the main sfs & the save file on that 2nd partition but keep initrd and
vmlinuz on the fat32 boot partition. I have been running such a config on one of
my sticks for some time. The boot codes were tricky to get right but are as follows:
Code: Select all
LABEL 5332
MENU LABEL Slacko 5.3.3.2 05/07/12
KERNEL /p5332/vmlinuz
APPEND initrd=/p5332/initrd.gz pmedia=usbflash pupsfs=sdb2:/p5332/puppy_slacko_5.3.3.2.sfs psavemark=2
but booting from SmartMedia......but thats another story!