Negotiated Link Speed only 1.5Gbps for 256GB SSD on 15" mid-2009 MBP?

Hi Daniel,

Actually is working, always is working at 3Gbps, but I connected to the sata2 (DVD sata) and i disconnect the DVD for ever.

I had that problem when i connected the ssd to the sata1, the negotiated link speed was 1.5Gbps.

Best,

Alvaro

AlvaroW wrote:

Hi Daniel,

Actually is working, always is working at 3Gbps, but I connected to the sata2 (DVD sata) and i disconnect the DVD for ever.

I had that problem when i connected the ssd to the sata1, the negotiated link speed was 1.5Gbps.

Sata1 (also known as Sata) has a max speed of 1.5GB/s, so if that is the connection you used the speed is correct.

my problem was that my intel 520 ssd is expected to run on sata2 (on macbook pro 2010 with MCP89 sata controller) but it is stuck on negotiated speed of 1.5G

so i was wondering if switching the ports between HD sata and DVD sata will solve this, and AlvaroW confirmed that it worked for him

i guess i'll give it a try

Do you have 2 hard drives fitted?

no. i have the SSD that i recently installed, and a DVD in the secondary sata

currently the SSD has negotiated speed of only sata1, instead of sata2

according to AlvaroW's advice, i thought i will try to switch the DVD and the SSD sata connections, hopefully that will enable sata2 speed on the hard drive

why do you ask?

The DVD bay may be sata only, the HDD bay (on 2009 models) is sata2.

But as you are usng the HDD bay you should get sata2 (3GB/s)

What is the transfer rate of the drive itself?

this is a mid 2010 macbook model with the same nVidia controller MCP89, negotiation speed should be sata2 but it is only sata1. this is a known issue with this specific sata controller

the drive itself is intel 520, which can reach sata3 (in this case it only sata2 due to macbook model limitation)

No idea why yours doesn't work, I get Sata2 on Macs from 2009 with no issue.

But it won't make a difference, the maximum transfer rate of your drive is 550Mb/s. The bus speed is 1500Mb/s

Your drive will work at the same speed on any sata bus, it is much slower than any variant of sata.

I have the same controller and its working. (i didnt install any driver). You can see that the ssd is installed in the dvd bay.

Csound1 you really are creating confusion on this issue.

SATA1 = 1.5Gigabits/s bus (capable of up to 187.5MegaBytes per second)

SATA2 = 3Gigabits/s bus (capable of up to 375MegaBytes per second)

SATA3 = 6Gigabits/s bus (capable of up to 750MegaBytes per second)

SSDs publish their speeds in MegaBytes/sec (not megabits)

So for many SATA3 (6G) SSDs publishing their max speed of 550MegaBytes per second will often be as fast as SATA3 can go in the real world.

and much faster than SATA2 or SATA1.

Yes, you're right, I erred, but .......

Show me a currently available SSD that can exceed 550MB/s, many don't even reach 375MB/s

As the speed increases the Sata bus will be inadequate, that's why Apple is switching (in many cases has already switched) to PCIe buses.

The fastest I have been able to find (outside of theoretical performance) is this.

Which would saturate a Sata or Sata2 bus under specific conditions, a Sata3 bus would not be saturated (not even close)

I have replaced Hitachi 250GB HDD of my Macbook Pro Late 2008 with Samsung 840 EVO SSD.

My computer is using Nvidia MCP79 chipset for SATA. With Hitachi 250GB HDD, the negotiated

link speed was 1.5Gbps. After replacing with Samsung 840 EVO, the negotiated link speed changed

to 3.0Gbps.

And I checked the specification of Hitachi 250GB HDD is compatible with SATA which only supports

1.5Gbps.

I think the negotiated link speed can be changed by the device connected.

I was able to have the link speed negotiate to 3.0 Gbps after turning on the laptop without any RAM installed. It will beep at you and won't boot, but turning on the computer without RAM also resets the firmware. After it beeps a few times, turn it off, re-install the RAM, and see what happens.

This worked for my Late 2008 MBP after I upgraded to a Kingston NOW SSD. Good luck.

After a bit of frustration trying to find a fix, one thing did end up working well for me. I read a claim somewhere that many of the mid 2009 models have faulty sata cables. Don't know if that's true and i'm not an expert. I swapped it out with http://www.amazon.com/Hard-Drive-Cable-MacBook-Unibody/dp/B00456S0IO/ref=cm_rdp_ product and now i'm runnning at 3gbps, with no problems so far. Might be worth a shot for anyone who hasn't tried that yet.

You can get 3 gb/s speed. Read my experience here: http://deepinsightsdotnet.blogspot.com/2015/10/late-2008-macbook-only-giving-15- gbs.html

You just have to get the right SSD.