Discussion

Sata vs Usb hard disk

24 23184
The speed can refer to http://sunxi.org/SATA

suberg  
Post Last Edited by suberg at 2014-7-8 02:37

I did a dd test on my BPI, here is the result:

root@lemaker:/media/新加卷# dd if=/dev/zero of=tt bs=1M count=4096
4096+0 records in
4096+0 records out
4294967296 bytes (4.3 GB) copied, 712.975 s, 6.0 MB/s
what's the problem?

Reply 12# suberg


   of=tt  ??? What is tt??

suberg  
Post Last Edited by suberg at 2014-7-8 19:04

tt is the output filename , current dir is /media/新加卷(the mount point of the sata disk,NTFS type )I also do a similar test via samba, the speed of copying a 256M file from BPI to win7 is about 11MB/s,  bottleneck seem to be the 100Mb/s network; however  the speed of copying a 256M file from win7 to BPI is about 4.1MB/s; posible bottlenecks are BPI's filesystem(ntfs-3g), BPI's samba server,or the board itself。
hdparm test gives a satisfactory result:

root@lemaker:/media# hdparm -tT /dev/sda
/dev/sda:
Timing cached reads:   540 MB in  2.00 seconds = 270.09 MB/sec
Timing buffered disk reads: 202 MB in  3.02 seconds =  66.89 MB/sec

so,what's the problem? thanks!

dd if=/dev/zero of=tt bs=1M count=4096, to test the speed, we need of=/media/sdX, sdX represent your hard drive., not of =tt file.

suberg  
Reply 15# tony_zhang
is there data loss risk for doing this ?

Reply 16# suberg

Yes. You'd better backup your sata data into PC.

some test here

--

SATA + SSD + Ext4 :

$ sudo hdparm -Tt /dev/sda

/dev/sda:
Timing cached reads:   544 MB in  2.00 seconds = 271.55 MB/sec
Timing buffered disk reads: 258 MB in  3.01 seconds =  85.60 MB/sec

--

USB + HDD + Ext4

$ sudo hdparm -Tt /dev/sdb

/dev/sdb:
Timing cached reads:   550 MB in  2.01 seconds = 274.27 MB/sec
Timing buffered disk reads:  62 MB in  3.07 seconds =  20.16 MB/sec

ddurdle  
what do you have hooked up to the sata power on the second photo?

Reply 18# moremusic

on my device with hdparm i get:

     Timing cached reads:   664 MB in  2.00 seconds = 331.48 MB/sec
Timing buffered disk reads:  72 MB in  3.00 seconds =  23.99 MB/sec

but with ftp or samba the speed is only 8MB/sec. What is the reason for the loss of 16MB/sec? Where can i find them?

You have to log in before you can reply Login | Sign Up

Points Rules