sata link speed on amd hudson

sata link speed on amd hudson

[Gottfried Haider]

Dear linux-ide,

i was setting up a linux install on a brand new Lenovo x120e laptop,
which is based on AMD's E-350 "Zacate" platform, when i realized that
the sata link speed was only reported as being 3.0 Gbps. While as far
as i know the particular machine has not been advertised as supporting
6 Gbps sata, i had expected the chipset to make use of it [1].

The controller device is a 1002:4391. I am using it with kernel
2.6.39-rc1 on an Intel SSD that supports 6 Gbps link speeds (as
confirmed by hdparm). In sysfs, I read sata_spd as "3.0 Gbps" and both
"sata_spd_limit" and "hw_sata_spd_limit" as "<unknown>".

On boot, the device comes up as:
ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
ata1.00: ATA-8: INTEL SSDSC2MH120A2, PPG2, max UDMA/133
ata1.00: configured for UDMA/133

Any suggestions?

thanks,
gohai


[1] http://ixbtlabs.com/articles3/mainboard/chipset-hudson-m1.html

Re: sata link speed on amd hudson

[Borislav Petkov]

+ Shane

On Sun, Apr 03, 2011 at 07:04:17AM +0200, Gottfried Haider wrote:
> Dear linux-ide,
> 
> i was setting up a linux install on a brand new Lenovo x120e laptop,
> which is based on AMD's E-350 "Zacate" platform, when i realized that
> the sata link speed was only reported as being 3.0 Gbps. While as far
> as i know the particular machine has not been advertised as supporting
> 6 Gbps sata, i had expected the chipset to make use of it [1].
> 
> The controller device is a 1002:4391. I am using it with kernel
> 2.6.39-rc1 on an Intel SSD that supports 6 Gbps link speeds (as
> confirmed by hdparm). In sysfs, I read sata_spd as "3.0 Gbps" and both
> "sata_spd_limit" and "hw_sata_spd_limit" as "<unknown>".
> 
> On boot, the device comes up as:
> ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
> ata1.00: ATA-8: INTEL SSDSC2MH120A2, PPG2, max UDMA/133
> ata1.00: configured for UDMA/133
> 
> Any suggestions?

Hmm, interesting. We had a similar issue already, see
http://marc.info/?t=128975810200005&r=1&w=2 and it could be that BIOS
is downgrading the sata link to save power, as Shane pointed out then.
Although in that case, it should detect a 6Gbps drive on the link and at
operate at least that link at full speed. Hmmm...

Gottfried, can you send full dmesg along with 'lspci -vvxxxx' as root
please?

Thanks.

-- 
Regards/Gruss,
    Boris.

Re: sata link speed on amd hudson

[Gottfried Haider]

Hi Borislav,

> Hmm, interesting. We had a similar issue already, see
> http://marc.info/?t=128975810200005&r=1&w=2 and it could be that BIOS
> is downgrading the sata link to save power, as Shane pointed out then.
> Although in that case, it should detect a 6Gbps drive on the link and at
> operate at least that link at full speed. Hmmm...
>
> Gottfried, can you send full dmesg along with 'lspci -vvxxxx' as root
> please?

I uploaded the files to http://sukzessiv.net/x120e - please let me
know if you need any additional info or testing.

greetings,
gohai

RE: sata link speed on amd hudson

[Huang, Shane]

Hi Gottfried,

> I uploaded the files to http://sukzessiv.net/x120e - please
> let me know if you need any additional info or testing.

> ahci 0000:00:11.0: AHCI 0001.0200 32 slots 1 ports 3 Gbps

http://marc.info/?l=linux-ide&m=128990190301535&w=2
http://marc.info/?l=linux-ide&m=128996215115401&w=2

Most likely your issue is same as the one above.

To limit max SATA speed to 3 Gbps is decided by platform vendor
like Lenovo, though our south bridge silicon can support 6 Gbps.

BTW, do you find any BIOS option which can enable 6Gbps? suppose
the answer is "no"...


Thanks,
Shane

Re: sata link speed on amd hudson

[Gottfried Haider]

Hi Shane,


>> ahci 0000:00:11.0: AHCI 0001.0200 32 slots 1 ports 3 Gbps
>
> http://marc.info/?l=linux-ide&m=128990190301535&w=2
> http://marc.info/?l=linux-ide&m=128996215115401&w=2
>
> Most likely your issue is same as the one above.
>
> To limit max SATA speed to 3 Gbps is decided by platform vendor
> like Lenovo, though our south bridge silicon can support 6 Gbps.

Can this bit be ignored/overwritten by the driver in theory?
How would you go on contacting the BIOS people working for Lenovo?

> BTW, do you find any BIOS option which can enable 6Gbps? suppose
> the answer is "no"...

nope, there is none.

thanks,
Gottfried

RE: sata link speed on amd hudson

[Huang, Shane]

Hi Gottfried,

> Can this bit be ignored/overwritten by the driver in theory?

I'm not quite sure, but anyway driver should not ignore/overwrite
it to modify the platform's policy, which was decided by OEM and
verified. We don't know any regression issue either.


> How would you go on contacting the BIOS people working for Lenovo?

Sorry, I don't have the contact window to Lenovo BIOS...


Thanks,
Shane

Re: sata link speed on amd hudson

[Gottfried Haider]

Hi Shane,


>> Can this bit be ignored/overwritten by the driver in theory?
> I'm not quite sure, but anyway driver should not ignore/overwrite
> it to modify the platform's policy, which was decided by OEM and
> verified. We don't know any regression issue either.

I understand the reasoning, just want to make clear that the disk
performance I am seeing is way below what I had expected. Now I don't
know if there is SATA 3 Gbps to blame or not - but since both the
chipset and the drive claim to support it _and_ the drive's specs
would warrant 6 Gbps (afaics), I'd really want to give that a try.

running hdparm -t /dev/sda on a new Intel SSD 510 (120GB) gives here:
Timing buffered disk reads: 360 MB in 3.01 seconds = 119.66 MB/sec

The drive has an advertised sequential read performance of "up to 400
MB/s (6Gbps)" and a real-world test (on Anandtech) shows at least
232.1 MB/s of that..

Any suggestions?