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SSD Question

Late 2009 27" imac 2.66 i5. I want to replace my optical drive with an SSD. OWC states: While a 6G SSD does function, it will only do so at SATA Revision 1.0 (1.5Gb/s, 150MB/s) speeds rather that the SATA Revision 2.0 (3.0Gb/s 300MB/s) speed the computer can deliver.

OWC recommends using their 3g model SSD which is more expensive than most 6gb units, in fact its about $45 more than the Samsung M500's that they've got on sale right now.

I also have an early 2009 macbook in which I've installed a Samsung 840 SSD. When I check System Profiler the negotiated link speed of the SSD is reported as 3gb. I don't understand why the Macbook would deliver 3gb but the iMac won't?

Has anyone here replaced the optical in their late 2009 imac with an SSD and what does system profiler report as the negotiated link speed with the 6gb ssd?

Thanks

Only the 21.5 and 27inch Core 2 Duo iMacs of late 2009 had the NVidia Controller that prevented a 6Gbps SSD running at the 3gbps max.

As far as my research has gone the iMacs of late '09 (11,1 which is yours) has an i5/i7 processor and an intel 5 series chipset which should have no problem running a Sandforce 6Gbps SSD in the optical slot.

Any SSD running at 6Gbps should work in your iMac's optical slot (Sandforce or not) and run at the correct 3.0gbps negotiated speed, as it has the intel chipset rather than the crappy NVIDIA one.

If you want to stay away from from sandforce driven SSD's I would probably use a Samsung Pro/Evo.

As for TRIM, in Mavericks I used a Trim-enabler on my OWC SSD and then learnt that they over-provision or something that handles data cleanup so there really was no need for it!

Most SSDs these days will have some form of inbuilt trim or data cleanup method.

It shouldn't matter which SSD is used 

Hope this helps somewhat   and Good Luck!

I don't understand why the Macbook would deliver 3gb but the iMac won't?

I don't have one, but as I understand it's due to how the SATA speed is negotiated, which must be inherent in some special chip on the Logic Board & Bus.

I picture it like this..

SSD reports 6Gb/s available, 2009 imac says no comprende, can you do 1.5 Gb/s, SSD says yes.

SSD reports 6Gb/s available, 2009 macbook says no comprende, can you do 3.0 Gb/s, SSD says yes.

(Vaguely similar thing with PM G5s, Some SATA drives that do 3.0 Gb/s or 3.0 Gb/s & 6.0 GBS won't work unless there's a true 1.5 Gb/s drive in SATA slot 0.)

(If the faster drive isn't in SATA slot 1 but in SATA slot 0, the G5 doesn't know how to negotiate the 3.0/6.0 connection, bit if Slot 0 has a true 1.5 Gb/s drive, then SATA connection doesn't fail & tells the 2nd faster drive it's readsy for SATA 1.5 Gb/s.)

Thanks BD. The imac has an Intel 5 series controller for both the hard drive and the optical, I don't know if they're seperate controllers or not. I'm going to get the controller info for the Macbook and do some searching to see if I can find more info. 3gb drives aren't easy to find and the ones I do are more expensive.

I have bought a ton of stuff from OWC through the years and they are pretty good on information.  Try the chat, they probably will be able to give you details.

I am in the same boat as you (sort of), one of my 2011 MacBook Pros about to go out of warranty and the Data Doubler for the Superdrive is recommended to use the 3G and not 6G drives due to compatibility issues.  It seems 6G in the Data Doubler on the 2011 will act buggy, which is a bummer in terms of what I can use in there.  I do have some older 3G drives so I may swap things around.  (Man, what I paid for the 3G 960 SSD for my tower not too long ago, so the prices look a bit better )

If I find any 3G drives while I am searching, will come back in here and let you know.

Thanks. I did get this from OWC tech support this morning:

Late 2009 iMacs have the NVidia MCP79 SATA controllers for both the HD bay and the optical bays. For this reason all 6G (SATAIII) drives will negotiate to SATAI 1.5 Gbps speeds while a 3G SSD will negotiate at the proper SATAII 3.0Gbps. If you want to run at full 3G capability in your machine you will need to install a 3G speed SSD. This is why the imac SSD/Doubler bundles we sell only come with 3G options.

Your Macbook5,2 should be the same as late-2009 imacs in terms of 6G (sataiii) drives. If you installed a 6G speed SSD it should only negotiate to 1.5Gb/s transfer rates. I do not see how it could operate at 3G given the known hardware conflict with that mac model and all 6G (sataiii) drives.

MAkes sense....EXCEPT....my late 2009 iMac 11,1 doesnt have the NVidia MCP79 controller, it has an Intel 5 series controller. My early 2009 Macbook does indeed have the NVidia MCP79 controller and a pre EVO Samsung 840 6G SSD but the negotiated link speed IS 3gb. Seems to totally contradict what her information is. I sent her screen shots of System Profiler windows from both machines illustrating what I'm saying but I haven't heard back yet.

I'm probably going to give up on this modification as it seems that at every turn there's another obstacle. I got this replay from OWC today:

The restriction is only for the Sandforce drive controller. I am sorry for the confusion. This does not include all drive controllers so the Samsung is not affected. That is why you are not seeing the problem with the Samsung. I hope this clears things up.

Great I think. I'll search Crucial M500 drives to see if they have Sandforce controllers. A quick check of Crucial's site doesn't really clear this up unfortunately. But then I find this https://www.larryjordan.biz/caution-ssd-drives-and-yosemite/ stating that because of changes in Yosemite's kext signing feature third party sad's won't work with Trim enabler. Well everything I've read suggests that it's foolish to run without Trim enabled.

I guess if I want to continue to do this I'm locked into OWC's 3G drive as they say that it doesn't need trim...thats great because it cost a third more than a Crucial M500. I'm not willing to experiment because I don't want to open my iMac more than is absolutely necessary...it doesn't look that easy.

So for now I'm going to leave this discussion open, maybe something will change.

Only the 21.5 and 27inch Core 2 Duo iMacs of late 2009 had the NVidia Controller that prevented a 6Gbps SSD running at the 3gbps max.

As far as my research has gone the iMacs of late '09 (11,1 which is yours) has an i5/i7 processor and an intel 5 series chipset which should have no problem running a Sandforce 6Gbps SSD in the optical slot.

Any SSD running at 6Gbps should work in your iMac's optical slot (Sandforce or not) and run at the correct 3.0gbps negotiated speed, as it has the intel chipset rather than the crappy NVIDIA one.

If you want to stay away from from sandforce driven SSD's I would probably use a Samsung Pro/Evo.

As for TRIM, in Mavericks I used a Trim-enabler on my OWC SSD and then learnt that they over-provision or something that handles data cleanup so there really was no need for it!

Most SSDs these days will have some form of inbuilt trim or data cleanup method.

It shouldn't matter which SSD is used 

Hope this helps somewhat   and Good Luck!

Thanks. That's pretty much what I've found doing a little more research myself. Trim on Yosemite, while it can be done, poses a security risk due to having to disable kext signing. Cindori, the developer of Trim Enabler, stated that they hoped that would change in the near future, so that leaves me with two choices wait and see what develops with Trim Enabler or buy an OWC SSD.

https://www.cindori.org

Hi

Did you get to fit an SSD?

Did the Intel series 5 controller work at 3.0 Gb/s?

I'm consideration the same upgrade

Thanks

Paul

Yes and yes! I used a Mercury 3G drive from OWC and their Data Doubler adapter to fit it in the optical drive bay. It works at full 3G speed, boots from startup chime to login screen in 13 seconds and applications fly open. Great upgrade, took me about 45 minutes start to finish.

I was really trying to confirm what Muufungman had said

"As far as my research has gone the iMacs of late '09 (11,1 which is yours) has an i5/i7 processor and an intel 5 series chipset which should have no problem running a Sandforce 6Gbps SSD in the optical slot."

Main reason is the OWC 3G SSD's are about twice the price of other SSDs capable of twice the speed.

OWC say it won't work and push their 3G brand. Muufungman do you know of someone how as actual experience of a 6GB/s SSD in a late 2009 iMac

Thanks, Paul

There is no reported conflict between the Intel 5 series controller and Sandforce drives. A SATA III drive will run at SATA II speed when connected. There is no conflict between either the Nvidia or Intel controllers using a non Sandforce drive. The conflict exists between the Nvidia MCP79 controller and Sandforce. I have an OWC SATA II drive, which uses Sandforce, in my iMac which is capable of 3GB and it runs at that speed, I also have a Samsung SATA III SSD, not Sandforce, in my Macbook which is capable of 3GB AND has the Nvidia MCP79 controller and it runs at full 3GB capable

I cannot offer proof because I chose OWC for a one atop shop and tech support if I needed it, but with this information I believe it,s safe to assume that a

SATA III drive will run at SATA II speed in a late 2009 iMac with the Intel controller.

Confused yet?

pgleesonuk wrote:

 

Main reason is the OWC 3G SSD's are about twice the price of other SSDs capable of twice the speed.

 

Capable of twice the speed in a different computer, not the late 2009 iMac. Regardless of how fast the SSD is capable of being it will only run at SATA II 3GB/s when connected to our model iMac. The Intel 5 series is a 3GB controller. A SATA III drive will never run at it's full capacity when connected to a SATA II controller.

These are the emails I got from OWC

I asked about the intel series 5 controller, if that has a problem with running at only 1.5 with a 6.0 SSD

"Yes it happens with both models, both controllers. This issue exists in many 2009 mac models not just the imac line so it is not limited to a specific controller.

It does not matter which OS version you use. The connections in that model are only 3G speed to begin with and have a known hardware (not software) conflict with all 6G (sataiii) drive"

I understand the limit in the 2009 iMac will always be 3.0 gb/s. But a 960GB OWC SSD is twice the price of a 1TG Samsung Evo 850.

So if I know it would work, I could get an SSD running at 3.0Gb/s at half the price OWC charge.

Maybe I just take the risk, and order an 6.0Gb/s SSD. If it defaults to 1.5 Gb/s, I will still see a good improvement is normal operations, since I does use big files like Photo / Video very often.

What model year is your Macbook

Thanks, Paul

As I said, the issue exists with SSDs that use Sandforce, Samsung does not use Sandforce. Again I have a 6Gb Samsung 840 in my early 2009 Macbook equipped with an Nvidia MCP79 controller and the negotited link speed is 3.0Gb/s

OWC sells drives that use Sandforce therefore the conflict exists in their drives. Of course they're going to steer us to their line with warnings about conflicts, only when pressed will they admit that drives without Sandforce work fine.

最后更新：2017-09-07 21:12:10

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