Link Speed and Negotiated Link Speed in my Mac Mini (Mid 2010)

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Link Speed and Negotiated Link Speed in my Mac Mini (Mid 2010)

I have a question regarding Link Speed and Negotiated Link Speed in my Mac Mini (Mid 2010)

I have a mac mini (Mid 2010), with 8 GB RAM and 320 GB HDD TOSHIBA MK3255GSXF (original Apple supplied) with NVidia MCP89 AHCI SATA-II.

With original Snow Leopard OSX, both the Link Speed as well as negotiated link speed were showing as 3 Gbps. My system would boot up in about 35 seconds, and Black Magic speed test indicated a disk speed of 85 to 103 MBps.

Then last year I upgraded to Mountain Lion. Still it was OK. This year sometime in Mar/Apr I had applied the latest OSX update (probably to 10.8.2 or so) when I started having this problem of reduced transfer speed. Boot up time started taking almost 90+ seconds and Black Magic Disk Speed test indicated that both read and write speeds had come done to 50-60 MBps. Link speed still indicated 3 Gbps but negotiated link speed came down to 1.5 Gbps.

Apparently there was SOMETHING in the upgrade to OSX during Mar/Apr that has cause this to happen. My Mac mini is SATA-II, and so is the HDD (as per Toshiba specs in their website). So why is there this mismatch ? Needless to say, even the overall speed of my Mac Mini has come down !

Subsequent updates to 10.8.3 and to the present 10.8.4 has not improved anything. I have even applied PRAM and SMC resets including a clean install of mountain lion, with no change. Perhaps somebody has an answer to this which I can apply to fix it ? Searches all over the mac forums and discussions have not yielded any positive suggestions.

A screen shot of the System Information is given here.

NVidia MCP89 AHCI:

Vendor: NVidia

Product: MCP89 AHCI

Link Speed: 3 Gigabit

Negotiated Link Speed: 1.5 Gigabit

Description: AHCI Version 1.30 Supported

TOSHIBA MK3255GSXF:

Capacity: 320.07 GB (3,20,07,29,33,376 bytes)

Model: TOSHIBA MK3255GSXF

Revision: FH415B

Serial Number: 60A3C06AT

Native Command Queuing: Yes

Queue Depth: 32

Removable Media: No

Detachable Drive: No

BSD Name: disk0

Rotational Rate: 5400

Medium Type: Rotational

Bay Name: Lower

Partition Map Type: GPT (GUID Partition Table)

S.M.A.R.T. status: Verified

Any help on this matter would be greatly appreciated.

OS X Mountain Lion (10.8.4), wireless Keyboard, Magic mouse, Samsung XL2370 LED monitor

Posted on Aug 11, 2013 3:23 AM

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Answer 1

BDAqua

Level 10

239,045 points

Aug 11, 2013 12:22 PM in response to Vajpai

Hello,

Open Console in Utilities & see if there are any clues or repeating messages.

Open console in Applications>Utilities, check the system log for the date/time of the last problem & the Startup right after that for clues.

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Answer 2

Vajpai Author

Level 1

15 points

Aug 13, 2013 10:37 AM in response to BDAqua

Dear BDAqua

Tried to get some clues as suggested by you, but I must admit, it was like trying to find a needle in a haystack. Failed to get any help from the Console logs. Nothing closely matching any references to link speeds.

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Answer 3

BDAqua

Level 10

239,045 points

Aug 13, 2013 11:45 AM in response to Vajpai

Hmmm, search All Logs for something like nvda right after the last startup.

8/11/13 Aug 11, 2013 9:51:57 AM kernel NVDANV40HAL loaded and registered.

Yours likely won't be the same as the one above.

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Answer 4

Vajpai Author

Level 1

15 points

Aug 15, 2013 4:04 AM in response to BDAqua

These are the last two entries found after the most recent boot.

14/08/13 9:05:46.000 PM kernel[0]: NVDANV50HAL loaded and registered

15/08/13 11:40:20.000 AM kernel[0]: NVDANV50HAL loaded and registered

However, I still cant make any head or tail of it ! Sure would like to know how to decipher this with the link speed issue.

BTW, I am no hardware and/or system programmer.

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Answer 5

BDAqua

Level 10

239,045 points

Aug 15, 2013 12:15 PM in response to Vajpai

Looks like a common problem for that SSD, possible a Firmware update changed it...

http://forum.corsair.com/v3/showthread.php?t=104301

http://apple.stackexchange.com/questions/73399/what-is-an-ssd-drives-negotiated- link-speed

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Answer 6

Vajpai Author

Level 1

15 points

Aug 18, 2013 4:13 AM in response to BDAqua

No luck with any of the links indicated in your reply.

The only viable explanation appears to be that my DVD drive may also be hooked on to the same SATA Cable as the HDD, which may have caused the negotiated link speed to drop to SATA 1 speed of 1.5 Gbps. However, this does not appear to be valid, simply because, earlier my HDD was operating at much higher speeds with a negotiated link speed at 3Gbps. Even then I had the DVD Drive. So what has changed now ? EFI firmware version is also the same as before, which happens to be the latest.

Not that my work is getting unduly hindered, but, I sure would like to know what is going on ?

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Answer 7

BDAqua

Level 10

239,045 points

Aug 18, 2013 11:57 AM in response to Vajpai

I'd like to know too, if you ever get anywhere on it.

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Answer 8

Nov 23, 2013 8:52 AM in response to Vajpai

Did you ever get this issue resolved? I'm having the exact same one with my Macbook Mid 2010. I installed an Intel 240gb SSD to up the speed and for whatever reason my negotiated link speed is stuck at 1.5gbs when the hard drive is a SATA III (6gbs) and the Nvidia SATA controller is supposed to run at 3gbs. Now obviously, even though my hard drive is a SATA III, Nvidia only supports up to II, but for some reason the hard drive is only performing up to I. Here's a screenshot of my setup:

I've been scouring the internet for this and it's gotten me almost nowhere. This SSD wasn't cheap and I expected to at least run twice as quickly as I was before.

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Answer 9

Vajpai Author

Level 1

15 points

Nov 24, 2013 2:21 AM in response to JossMcBoss

Dear Joss

Unfortunately I am still stuck with this probelm and no one appears to able to solve it for me. Least of all Apple themselves. Meanwhile I have tried twice to get rid of it by a fresh install but to no avail. Still waiting for some solution from someone, and, that is why I have yet to go the SSD way. No point in wasting hard earned money if it is not going to produce the desired result.

Somehow, I have this feeling that Mac Mini Mid 2010 was a defective design to which Apple is not acknowledging as it is an end of line model. I had already brought to their notice that my system has already had 4 trips to their repair center (one yet to report - the last trip for a defective DVD Drive) and on two occasions the mainboard itself was changed. And now, even my Applecare support has come to an end ! So next time it becomes faulty, I will be forced to simply dump it ! A pretty heavy price to pay for a product that is going to last only 3 years !

Till then, I will keep trying to research on how to overcome this problem. It has now become more of an academic interest than anything else. Will keep this post updated as and when I get a solution. There is no other suggestion from the entire Apple community or Apple Inc for this unique problem.

Please do let me know in case you are able to resolve this problem.

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Answer 10

Nov 24, 2013 10:25 AM in response to Vajpai

Wow sounds like your little guy is just a gauntlet of issues. I'm definitely going to keep talking to people and researching the problem and toying around with this computer. While having a ssd at all definitely makes the computer a good bit faster (the shutdown and startup time is like lightning), I paid for a SATA III ssd expecting to get a 3gb link speed to the drive and that's what I expect.

I'm going to talk to Applecare again today (the dude just had me run disk permissions/disk scans and repairs so far, not sure what that's going to do (not to mention the scans took an extremely long time for whatever reason), but I'm sort of at a dead end so I can't complain.

But I'll definitely keep you updated on any steps I take to clear up the issues.

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Answer 11

Nov 29, 2013 2:06 PM in response to Vajpai

Hello!! I have the same problem with you..

when i upgrade my mac mini mid 2010 with 8gb ram and ssd corsair force gs 128gb

i realized that was going slow, after i was search,

I made some experiments on mac mini and i find that,when i open the mac and reset NVRAM / PRAM,

the system recognizes 3Gb/s then i restart it and it still recognizes 3Gb/s.

when i shut it down and open it again recognize 1,5Gb/s.

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Answer 12

Vajpai Author

Level 1

15 points

Nov 30, 2013 3:21 AM in response to stellbouz

You are facing this problem because the SATA controller in your Mac Mini is from NVIDIA, and you are now getting a negotiated link speed of 1.5 Gbps instead of 3 Gbps. Your upgrade to an SSD will not improve speed untill the negotiated speed is also matched to the Link Speed.

Kindly keep following this discussion and am sure somebody will work out a solution. So far I have not been able to resolve this issue. I am still on it and trying to find a solution.

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Answer 13

Feb 23, 2014 10:51 PM in response to Vajpai

Hi,

Was this issue ever solved??

I have the same problem with a MacBook pro mid 2010, Nvidia MCP89 controller and a intel 520 SSD.

like speed is only 1.5Gbps and not 3Gbps (SATA2)

cannot seem to increase link speed, tried everything..:\

Thanks,

Daniel.

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Answer 14

keg55

Level 6

11,743 points

Feb 24, 2014 6:07 AM in response to danielpo123

danielpo123 wrote:

Hi,

I have the same problem with a MacBook pro mid 2010, Nvidia MCP89 controller and a intel 520 SSD.

like speed is only 1.5Gbps and not 3Gbps (SATA2)

I had similar issues with a late-2008 Macbook Pro when I swapped the HDD with an Intel 520 SSD. Similar nVidia controller. The drive could be seen and OS X could be installed, but it would never boot from the SSD. With the Option/Alt key pressed at startup the Macintosh HD and Recovery HD would show momentarily then disappear (poof cloud animation). Booted from an external drive with OS X, the Intel 520 SSD showed a Linked speed of 3Gbps and Negotiated of 1.5Gbps.

I switched out the Intel 520 with a Crucial M500 SSD and both the Linked and Negotiated speeds showed 3Gbps (SATA II). The Crucial SSD works fine even though the controller is SATA 2 not 3.

So, I've concluded that the Intel 520 Series SSDs "don't play nicely" with nVidia SATA controllers. They DO, however, work fine without issue in a Mac with the Intel SATA controller.

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Answer 15

Vajpai Author

Level 1

15 points

Feb 24, 2014 6:57 AM in response to danielpo123

Dear Daniel

So far I have not been able to resolve this issue. Not that my work suffers but still waiting for some lead from somewhere. It may be an issue related to mismatch of modern devices with older controllers which have now become obsolete. This is what I infer from Keg55's response.

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