# SATA Samsung F1 copying performance

## w00ter

I've recently installed a new SATA Samsung HD, the HD753LJ. It runs on my Silicon Image si3114 controller (bios 5.0.64, any other didn't recognize the HD and hanged) inbedded in my motherboard (dfi NFII infinity nforce2). Copying files from one partition to another is really slow, we're talking about 3 to 5 MB a second. Copying a file to /dev/null gives about 85 MB a sec and copying to another disk is limited by the other disks write performance (about 40 MB a sec). The other disk, an older SATA WD, copies files from one partition to another at about 40 MB a second. 

The kernel I am currently using is 2.6.22-gentoo.  sdparm -a /dev/sda /dev/sdb gives exactly the same features turned off and on on both disks. I know that the Samsung has NCQ and is SATAII.

Any ideas on how to speed up copying files on the HD?

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## twam

I've got the HD753LJ twice and had problems with NCQ on a Silicon 3132 and the Intel ICH7 Controller. The disk was hanging up, when transfering lots of data, but speed was ok (~90 MB/s). 

Maybe disabling NCQ is helping you too. Try

```
echo 1 > /sys/block/sda/device/queue_depth
```

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## drescherjm

 *Quote:*   

> Copying files from one partition to another is really slow, we're talking about 3 to 5 MB a second.

 

This is probably due to thrashing. I mean hard drives are very fast for sequential reads / writes but if the data is not sequential (causing the heads to have to move) the speed will be significantly slower.

To lessen this effect you may want to tune your cache and possibly your file system write policy to avoid the file system wanting to write to disk as soon as possible,

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