# SATA II - Increasing speed?! [SOLVED]

## Mehlano

Hi all!

..is that right?

```
gentie linux # hdparm -tT /dev/sda

/dev/sda:

 Timing cached reads:   1976 MB in  2.00 seconds = 987.61 MB/sec

 Timing buffered disk reads:  220 MB in  3.01 seconds =  73.11 MB/sec

```

```
gentie linux # hdparm -tT /dev/sdb

/dev/sdb:

 Timing cached reads:   1974 MB in  2.00 seconds = 987.29 MB/sec

 Timing buffered disk reads:  220 MB in  3.01 seconds =  73.17 MB/sec

```

/dev/sda is a real (really!!) SATA II HD. My motherboard/chipset supports 300 Gbit/s (Edit: Gbit/s instead of Mb/s  :Smile:  ) SATA (2)  HDs, too. 

/dev/sdb is a SATA I HD. So it's okay.. but... why is sda so "slow"? 

```
gentie linux # lspci

00:00.0 Host bridge: Intel Corporation 945G/GZ/P/PL Express Memory Controller Hub (rev 02)

00:01.0 PCI bridge: Intel Corporation 945G/GZ/P/PL Express PCI Express Root Port (rev 02)

00:1c.0 PCI bridge: Intel Corporation 82801G (ICH7 Family) PCI Express Port 1 (rev 01)

00:1c.3 PCI bridge: Intel Corporation 82801G (ICH7 Family) PCI Express Port 4 (rev 01)

00:1d.0 USB Controller: Intel Corporation 82801G (ICH7 Family) USB UHCI #1 (rev 01)

00:1d.1 USB Controller: Intel Corporation 82801G (ICH7 Family) USB UHCI #2 (rev 01)

00:1d.2 USB Controller: Intel Corporation 82801G (ICH7 Family) USB UHCI #3 (rev 01)

00:1d.3 USB Controller: Intel Corporation 82801G (ICH7 Family) USB UHCI #4 (rev 01)

00:1d.7 USB Controller: Intel Corporation 82801G (ICH7 Family) USB2 EHCI Controller (rev 01)

00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev e1)

00:1f.0 ISA bridge: Intel Corporation 82801GB/GR (ICH7 Family) LPC Interface Bridge (rev 01)

00:1f.1 IDE interface: Intel Corporation 82801G (ICH7 Family) IDE Controller (rev 01)

00:1f.2 IDE interface: Intel Corporation 82801GB/GR/GH (ICH7 Family) Serial ATA Storage Controller IDE (rev 01)

00:1f.3 SMBus: Intel Corporation 82801G (ICH7 Family) SMBus Controller (rev 01)

01:01.0 Multimedia audio controller: VIA Technologies Inc. VT1720/24 [Envy24PT/HT] PCI Multi-Channel Audio Controller (rev 01)

01:02.0 Ethernet controller: 3Com Corporation 3c905C-TX/TX-M [Tornado] (rev 78)

02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. Unknown device 8168 (rev 01)

04:00.0 VGA compatible controller: nVidia Corporation NV43 [GeForce 6600] (rev a2
```

```
gentie linux # cat /proc/scsi/scsi

Attached devices:

Host: scsi0 Channel: 00 Id: 00 Lun: 00

  Vendor: AOPEN    Model: DVD1648/AAP PRO  Rev: 1.04

  Type:   CD-ROM                           ANSI SCSI revision: ffffffff

Host: scsi1 Channel: 00 Id: 00 Lun: 00

  Vendor: ATA      Model: ST3320620AS      Rev: 3.AA

  Type:   Direct-Access                    ANSI SCSI revision: 05

Host: scsi2 Channel: 00 Id: 00 Lun: 00

  Vendor: ATA      Model: ST3808110AS      Rev: 3.AA

  Type:   Direct-Access                    ANSI SCSI revision: 05

Host: scsi2 Channel: 00 Id: 01 Lun: 00

  Vendor: TSSTcorp Model: CD/DVDW SH-W163A Rev: TS01

  Type:   CD-ROM                           ANSI SCSI revision: 05
```

Is there any chance to use sdparm or hdparm to increase and use the full abilities of my SATA II drive ?

----------

## NaiL

Can you try that connecting *only* the Sata2 HD?

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## drescherjm

I am confused as both buffered disk reads are good. The other benchmark measures more cpu / memory performance than disk/controller. 

What do you mean slow? 

Were you expecting SATA2 to be better than SATA1? If so you have to understand that no one makes a single drive that can saturate the SATA1 bus (150MB/s) so SATA2 is not going to give you that much. It has an improved protocol and will improve in cache transfers from the hard drives cache to memory but since the hard drive's cache is only 16 MB you will never be able to benchmark this increased transfer rate.

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## Mehlano

Hm..

..okay, u ask me why I'm wondering?

It's simple:

```

SATA 1.5Gb/s                                                

1500MHz embedded clock                           

x    1 bit per clock                                    

x    80% for 8b10b encoding                   

/     8 bits per byte                              

=    150 Mbytes/sec                                 

 

SATA 3Gb/s  

3000MHz embedded clock

x         1 bit per clock

x          80% for 8b10b encoding

/          8 bits per byte                         

=         300 Mbytes/sec

```

..that's why I'm wondering - my 150 HD has the same speed as my 300 HD.

It's clear, that I'll never come up to 300 Mbytes/sec effective speed with that HD. But more as the 150' HD isn't only a dream, or isn't it so ?  :Question: 

Edit: that SATA II drive has 16 MB of cache on board   :Rolling Eyes: 

----------

## lagalopex

 *drescherjm wrote:*   

> Were you expecting SATA2 to be better than SATA1? If so you have to understand that no one makes a single drive that can saturate the SATA1 bus (150MB/s) so SATA2 is not going to give you that much. It has an improved protocol and will improve in cache transfers from the hard drives cache to memory but since the hard drive's cache is only 16 MB you will never be able to benchmark this increased transfer rate.

 

Yes, the drives are actually not able to read faster. sata itself could be much faster but the drives are to slow... but you can take a hd with 10k rpm or even more.

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## Mehlano

Okay, that's the answer I wanted to solve.

Answer: SATA2 is -able- to run faster... but my drive and other 7200 rpm drives aren't able to be that fast as the controller can be/handle!

Fine..

..thank u for enlighting me!  :Smile:   :Idea: 

----------

## drescherjm

 *Quote:*   

> but my drive and other 7200 rpm drives aren't able to be that fast as the controller can be/handle! 

 

The fastest drives are 15k scsi drives and they have a transfer rate around the 90 to 100 MB/s mark. 

Its going to be a few years until even sata1 is saturated. This will come with increasing the density of the platters and not increasing the spindle speed of the drive. The idea is if you pack 2 times the bits in the same area on the disk the electronics can be designed to have 2 times the transfer rate. So we need to wait for something like 512 GB platters and drive sizes of 512G, 1TB, 1.5TB and 2TB.

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## pknet

Mehlano, 

Have a try with a WD Raptor. It really changes your machine. Just the old version SATA I is enough. It is a sata drive with a typical scsi architecture (you can also understand from their typical sizes: 36GB, 74GB and so on... )  @10000rpm.  I think it is still the only 10000rpm SATA on the market. If performance is a must for you and you don't need huge space this is your choice. 

It's wonderful.

bye

..... I think I'd have to ask WD a commission on their raptor sales   :Laughing: 

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## drescherjm

 *Quote:*   

> Have a try with a WD Raptor. It really changes your machine. 

 

If you do make sure it is a current model and not one from 2 years ago as it will be slower (transfer rate but better seeks) than the current 7200 drives which have STRs of around 75MB/s and seeks around 10ms.

----------

