SATA negotiated speed

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SATA negotiated speed

O.P.

Hi.

Trying to establish if the optical SATA connection on an early 2009 iMac will achieve SATA 2 speed of 3GB with a crucial MX200 500GB SSD. Have already tried a Sandisk ultra 2 with Marvell controller and only achieved a negotiated speed of SATA 1 which is 1.5Gbits.

Speculation on the Internet is the optical connector is limited to SATA 1 but when I go into system report it shows the port is capable is SATA2 but negotiated at SATA1. Don't want to tear this iMac down again until I'm sure it will work at SATA 2 speed.

Thank You

iMac, OS X El Capitan (10.11.2), Early 2009 iMac...9,1

Posted on Jan 3, 2016 1:12 PM

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Answer 1

SeaPapp

Level 7

26,492 points

Jan 3, 2016 2:43 PM in response to daveeyt

The SATA connection in the optical bay is SATA 3.0 Gb/s. It's likely your iMac has an Nvidia MCP79 SATA controller which will limit speeds of some 6Gb/s SSD's to SATA 1 speed. The conflict relates to the Sandforce tecnology and apparently the Marvell controller uses Sandforce. Your's is the second instance of the problem with a Marvell controller that I've responded to in the past week. Return the SSD for a refund and get a Samsung or go to OWC and get one of their 3Gb SSD's http://eshop.macsales.com/

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Answer 2

daveeyt Author

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Jan 3, 2016 2:52 PM in response to SeaPapp

HI Mike. Thank you very much for the reply. And yes it is the MCP79. I Was not aware the Marvell uses sandforce. I Have already arranged an RMA but ordered a crucial Mx200 that is due to be delivered next week. Do you know if the crucial will work, or do I need to cancel and order the Samsung...assume it's the EVO 850....

please advise on the 2 questions if you have time.

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Answer 3

SeaPapp

Level 7

26,492 points

Jan 3, 2016 2:57 PM in response to daveeyt

I wasn't aware that Marvell used Sandforce either but the conflict is certainly the same. I don't know about the Crucilal drives, your best bet would be to call them and ask, pr hopefully someone here will chime in with their experience. I have a Samsung 840 (pre evo) in my early 2009 macbook with the Nvidia controller and I have an OWC 3G drive in the optical bay of my 2009 iMac.

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Answer 4

SeaPapp

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26,492 points

Jan 3, 2016 3:01 PM in response to daveeyt

Crucial lists the BX200 as compatible with your iMac http://www.crucial.com/usa/en/compatible-upgrade-for/Apple/imac-%28early-2009%29 -imac9%2C1

Edit: Sorry I clicked "more upgrades" and the Mx200 is also listed

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Answer 5

daveeyt Author

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Jan 3, 2016 3:10 PM in response to SeaPapp

Hi Mike. I Did also buy a 120 gig Sandisk ultra II at the same time and fitted this to my late 2008 macbook unibody IN THE HDD SLOT. This has the same MCP79 but runs consistently at SATA 2. But do know the 120 gig drive has a different Marvell controller. I will call crucial tomorrow. maybe there is some truth in the rumours that the ODD connector is handicapped in the 9,1 iMac

THANK YOU

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Answer 6

SeaPapp

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26,492 points

Jan 8, 2016 9:55 AM in response to daveeyt

There is NO truth to that rumor. I have an SSD running at 3Gb speed in the optical bay of my 2009 iMac. Since Crucial shows the Mx200 as compatible I believe it will work but calling them will confirm. If you had a 3Gb drive it would work, the conflict is with some 6Gb drives and the Nvidia controller.

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Answer 7

daveeyt Author

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Jan 3, 2016 3:24 PM in response to SeaPapp

Thanks again Mike. will let u know

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Answer 8

daveeyt Author

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Jan 5, 2016 2:57 PM in response to daveeyt

Spoke to crucial advanced technical team. They are certain the MX200 drive is compatible and will negotiate correct SATA speed. The crucial Drive arrived today, will swap out the Sandisk in next few days And fit the crucial in the optical bay.

Does anyone foresee a problem to swap the 3.5 western digital blue for a 1TB western digital black, don't want to invite any heat related problems.

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Answer 9

SeaPapp

Level 7

26,492 points

Jan 5, 2016 3:41 PM in response to daveeyt

Apple started using OEM drives that had the temp sensors built in as opposed to an external temp sensor in 2009. That may be the only problem I forsee, and it's not a big problem as OWC offers an adapter cable that provides an inline external sensor http://eshop.macsales.com/item/OWC/DIDIMACHDD09/ The cable allows your system to read the drive temp and properly control the fans without software hacks.

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Answer 10

daveeyt Author

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Jan 5, 2016 4:03 PM in response to SeaPapp

HI mike. Thanks. I checked and the early 2009 has the heat sensor simply stuck to the drive not embedded. wasn't sure if the operating temp of a WD black would cause any issues versus the stock drive temp in theimac . THEY'RE BOTH 7200 drives so I am inclined to think will be ok. My plan is to create a 1.5TB FUSION DRIVE.

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Answer 11

daveeyt Author

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Jan 8, 2016 9:55 AM in response to SeaPapp

installed the crucial 500GB MX200 in the optical tray and immediately negotiated 3Gbits SATA2 speed. Going for a straight install (non fusion) for now until I figure out if the risk of data loss and overhead of a fusion is really needed.

Thank you Mike for your support. It's appreciated.

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Answer 12

daveeyt Author

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Jan 13, 2016 3:24 PM in response to daveeyt

UPDATE

the crucial mx200 consistently runs at SATA 2 in the iMac early 2009 with MCP79 controller, the Sandisk ultra2 480Gb consistently runs at SATA 1 in same computer same slot.

both the 120Gb Sandisk and the 480Gb Sandisk run consistently at SATA2 in macbook early2008 with MCP79 controller

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Answer 13

SeaPapp

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26,492 points

Jan 13, 2016 4:08 PM in response to daveeyt

There's obviously a conflict with the Marvell controller on the Sandisk drives and the Nvidia MCP79 controller in the Mac.

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