# SSD performance (SOLVED)

## andrewwalker27

I've recently installed a SSD to my motherboard and I'm not sure if it is running at full speed or not. I've tried to find out but I get this ambiguous message,

```

PhenomIIx6 fred # smartctl -a /dev/sda | grep "^SATA"

SATA Version is:  SATA 3.2, 6.0 Gb/s (current: 3.0 Gb/s)

```

The SSD is as folllows,

```

PhenomIIx6 fred # sudo hdparm -I /dev/sda | egrep "Model|speed|Transport"

        Model Number:       SanDisk Ultra II 480GB                  

        Transport:          Serial, ATA8-AST, SATA 1.0a, SATA II Extensions, SATA Rev 2.5, SATA Rev 2.6, SATA Rev 3.0

           *    Gen1 signaling speed (1.5Gb/s)

           *    Gen2 signaling speed (3.0Gb/s)

           *    Gen3 signaling speed (6.0Gb/s)

```

Does anyone know why it says (current: 3.0 Gb/s)? Is it because there is an issue with the cable (I thought they were all pretty much the same)? Are my other SATA devices causing the speed reduction?

Can anyone explain to me what is going on?Last edited by andrewwalker27 on Sat Jan 23, 2016 4:50 pm; edited 1 time in total

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## NeddySeagoon

andrewwalker27,

Please put dmesg on a pastebin.

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## andrewwalker27

Ok, never used pastebin before, hope this works!

[url]

http://pastebin.com/uqF61Bgq

[/url]

Think I've found the problem though,

```

[    5.525754] ata1: limiting SATA link speed to 3.0 Gbps

[    5.525759] ata1.00: exception Emask 0x10 SAct 0x2 SErr 0x280100 action 0x6 frozen

[    5.525761] ata1.00: irq_stat 0x08000000, interface fatal error

[    5.525764] ata1: SError: { UnrecovData 10B8B BadCRC }

[    5.525766] ata1.00: failed command: READ FPDMA QUEUED

[    5.525770] ata1.00: cmd 60/08:08:58:1c:01/00:00:02:00:00/40 tag 1 ncq 4096 in

                        res 40/00:0c:58:1c:01/00:00:02:00:00/40 Emask 0x10 (ATA bus error)                                                                                                                                                                                                    

[    5.525772] ata1.00: status: { DRDY }

[    5.525776] ata1: hard resetting link

[    5.985836] ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 320)

[    5.988382] ata1.00: configured for UDMA/133

[    5.988390] ata1: EH complete

```

I suspect dodgy cables, I'll swap them out and see if it helps.

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## frostschutz

try a different cable and a different port, and finally a different controller...

Running SATA II is not a problem, you won't notice a difference (SSD speed is more about access times rather than throughput), but those SATA errors are not good.

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## NeddySeagoon

andrewwalker27,

dmesg shows that the kernel tried to run the SATA link at 6G and after a number of errors, it gave up 6G and tried 3G. 

```
[    5.294690] ata1: SATA link up 6.0 Gbps (SStatus 133 SControl 300)

[    5.297229] ata1.00: configured for UDMA/133

[    5.297237] ata1: EH complete

[    5.344030] random: nonblocking pool is initialized

[    5.525754] ata1: limiting SATA link speed to 3.0 Gbps
```

frostschutz has already suggested a good set of diagnostics.

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## andrewwalker27

Thanks gents, it looks like some sata cables are more equal than others! Unfortunately none of the cables I have specify the sata version they're rated for, which doesn't help.

Now I've changed them out the results look better and the errors have gone.

```

PhenomIIx6 fred # smartctl -a /dev/sda | grep "^SATA"

SATA Version is:  SATA 3.2, 6.0 Gb/s (current: 6.0 Gb/s)

```

Thanks again, I'll mark this as solved.

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