# [Solved] intel 875p + SATA

## luminoso

Hi...

I discovered that my gentoo box is having a degraded performance.

The problem is that:

Gentoo:

 *Quote:*   

> /dev/sda:
> 
>  Timing cached reads:   2122 MB in  2.00 seconds = 1061.66 MB/sec
> 
>  Timing buffered disk reads:  168 MB in  3.02 seconds =  55.60 MB/sec

 

Ubuntu 6.06 LTS Live CD:

 *Quote:*   

> /dev/sda:
> 
>  Timing cached reads:  4470 MB in  2.00 seconds = 2235.66 MB/sec
> 
>  Timing buffered disk reads:  168 MB in  3.02 seconds =  55.60 MB/sec

 

My Actual gentoo system is:

 *Quote:*   

> uname -a
> 
> Linux khona4 2.6.20 #5 SMP PREEMPT Mon Feb 12 01:56:44 WET 2007 i686 Intel(R) Pentium(R) 4 CPU 2.80GHz GenuineIntel GNU/Linux

  (vanilla)

And some kernel configs:

 *Quote:*   

> 
> 
> ATA/ATAPI/MFM/RLL support (IDE) [Y/n/m/?] y
> 
>   Max IDE interfaces (IDE_MAX_HWIFS) [4] 4
> ...

 

 *Quote:*   

> 
> 
> *
> 
> * SCSI device support
> ...

 

 *Quote:*   

> 
> 
> *
> 
> * Serial ATA (prod) and Parallel ATA (experimental) drivers
> ...

 

My problem is why ubuntu have the DOUBLE of the Timing cached reads results.

But after all, by gkrellm2 if i do "cat /dev/sda > /dev/null" i got ~55MB/sec   :Confused: 

At dmesg i got this strange thing at boot:

 *Quote:*   

> SCSI device sda: write cache: enabled, read cache: enabled, doesn't support DPO or FUA

 

Thanks for all.

SOLVED: HDPARM BUGLast edited by luminoso on Fri May 18, 2007 1:15 am; edited 2 times in total

----------

## d2_racing

Remove the ATAPI SECTION and use the new PATA-SATA  section.

----------

## luminoso

 *d2_racing wrote:*   

> Remove the ATAPI SECTION and use the new PATA-SATA  section.

 

you mean:

Intel PIIXn chipsets support (BLK_DEV_PIIX) [Y/n/m/?] y to NO ?

I tried that. No effect on sda hdparm and i can't set DMA on the rest of the devices.

----------

## ksp7498

Same issue here on Intel's ICH7 on vanilla-sources-2.6.20

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

/dev/sda:

 Timing cached reads:   1602 MB in  2.00 seconds = 800.58 MB/sec

 Timing buffered disk reads:  206 MB in  3.02 seconds =  68.19 MB/sec

```

The cached reads should be much higher than that.

----------

## luminoso

Please. Anyone else with this problem?

anyone with ICHx without this problem?

----------

## d2_racing

No I mean :

 *Quote:*   

> 
> 
> # 
> 
> # ATA/ATAPI/MFM/RLL support 
> ...

 

----------

## luminoso

Ok. I did just like you said.

hdb disk become sda

sda become sdb

sdb become sdc

Ok. booted.

No DMA for hdb (now sda) device.

hdparm -tT /dev/sdc continues to report low speeds.

@ ksp7498 : please can you also test this?

----------

## ksp7498

okay I configured my kernel as d2_racing recommended.  Just like you mentioned all of my drives became shifted by one letter (since hda became sda), however I'm not really seeing much of a difference performance-wise.

```
descartes keith # hdparm -tT /dev/sdb

/dev/sdb:

 Timing cached reads:   1754 MB in  2.00 seconds = 876.33 MB/sec

 Timing buffered disk reads:  202 MB in  3.02 seconds =  66.90 MB/sec

```

the cached reads are a bit faster but still nowhere near the ~2000 MB/sec they should be at.

I'm considering going back to a 2.6.16 kernel, the last kernel under which my disk subsystem actually worked properly.

----------

## luminoso

 *ksp7498 wrote:*   

> 
> 
> I'm considering going back to a 2.6.16 kernel, the last kernel under which my disk subsystem actually worked properly.

 

why? i didn't notice any performance leak. Here is just numbers.

 *luminoso wrote:*   

> But after all, by gkrellm2 if i do "cat /dev/sda > /dev/null" i got ~55MB/sec

 

----------

## luminoso

had someone tested this with last -mm kernel?

----------

## jayson

It works for me fine with kernel 2.6.20 (vanilla and gentoo-sources).

I get:

 *Quote:*   

> 
> 
> jaylab jay # hdparm -tT /dev/sda
> 
> /dev/sda:
> ...

 

You may check out my .config here.

However I have a problem with my DVD Drive. Here I have already posted to the mailinglist without any useful results. I have uploaded the output of lspci -vv (http://www.web-upload.com/download_45807.html?her=dateimanager&order=uploaddatum&dir=DESC&von=0&where=)

If you got a similar (ICH7 and SATA) configuration and your DVD Drive works well it would be very nice if you could send me your .config or post it bellow.

My e-mail is: jakob dot buchgraber at gmail dot com

Cheers,

Jay

----------

## luminoso

hummm i used your config and still having issuses. smells like kernel bug?

Also, i think about your dvd wirter you dont have any ATAm support, this means thatyou cant set any DMA+32bit performace at all in hdparm, right?

Did someone tested mm patch??

----------

## luminoso

i'm using 2.6.21-gentoo and stills the same.

I don't know what way to go from now on to solve this...

----------

## Desintegr

The hdparm used in Dapper (version 6.3) was bugged.

You can read this in hdparm changelog :

 *Quote:*   

> hdparm-6.9 :
> 
> 	- fix X2 over-reporting of -T results

 

I think there is no problem with your Gentoo installation. You should try with a newer Ubuntu LiveCD and verify your "cached read" performances.

----------

## luminoso

thanks!!  :Smile: 

----------

