Best COMPATIBLE ssd for NVidia MCP79 chipset?

The 2009 firmware update for the iMac9,1 pertains to the video card. Furthermore, I already had it installed (yes, I checked just now).

iMac EFI Firmware Update 1.4

I then performed an SMC and PRAM resets just now, as per this:

iMac SMC and PRAM reset

Upon rebooting my iMac9,1 and running the Black Magic Disk Speed Test, I found that I am still getting slow SATA-I speeds.

Again, this is so strange. The MBP5,5 has the same NVidia chipset, yet the iMac9,1 gets SATA-I while the MBP5,5 gets SATA-II, both with the same exact SSD and same disk contents!!

the funny thing is that apple will not give you an explanation about this so I have no idea about this all I know is that anyone with the nvidia chipset would get a hit or miss with getting SATA 2 on it, some has report SATA2 and some had the bad luck of SATA 1

All I could say is for those with SATA 1 to do a raid 0 and maybe they could get speeds of Sata 2 but I would not recommend doing any raid with the nvidia chipset.

I am curious about TRIM. As mentioned earlier in this discussion, later versions of Yosemite and all versions to date of El Capitan make it easy to enable TRIM on 3rd party SSDs via a simple Terminal command. But that command is OS dependent. Meaning, if I boot from an external drive (which could have Yosemite or and even older OS), I would assume that TRIM would then become DISABLED for attached 3rd party SSDs?

Also, if we keep updating El Capitan, over time will our TRIM setting ever become disabled?

Making sure TRIM is ALWAYS enabled is an important point of consideration. Any thoughts on this?

Thanks.

thats a very good question, it all depends if you backward restore to yosemite, and check if trim is still enable...

The reason I ask is because in this thread we are talking about 2009 Macs. My late 2009 iMac11,1 originally came with Snow Leopard (10.6). I still have a 1TB external FW800 drive running that OS, and I occasionally boot into it if my son wants to run some old games that don't work on newer OS's. But in that case, what would happen to the SSD? Clearly, TRIM is not support on OS 10.6, so assuming the SSD even mounts fine, then writing to it and deleting files from it may be problematic in a way that you would never notice. Since TRIM deals with deleted files, if you booted into your 10.6 external HDD and then deleted some files from your SSD, there would be no TRIM enabled at the OS level, so what happens? Those delete bytes are not taken care of by TRIM, so are they considered "irrecoverably lost forever"? Think about what happens to an SSD over time if TRIM is never enabled.

But this would apply to any SSD with any OS. Let's say you have an SSD but did not enable TRIM. You use it for 1 year, and then you read that TRIM is good to enable, so you enabled it via the Terminal. Over that past year, no doubt you deleted many files. Does enabling TRIM magically fix all the garbage collection of the past? Or does it only apply to files you newly delete AFTER TRIM has been enabled?

http://www.tomshardware.co.uk/forum/279412-32-trim-garbage-collection-beating-de ad-horse#12258914

If you haven't seen this particular page scroll about half way down to the post by Kent Smith, very informative.

Mike, as always, thank you for your helpful input. I found points (9) & (12) in that Dec. 2013 talk by Kent Smith (Director of Marketing for Sandforce) to be of interest. (Note though that links to his blog and PDF are now dead.) Specifically, he says Garbage Collection (GC) exists even without TRIM enabled but invalid data would be tossed to and fro on the SSD in that case; however TRIM, once enabled, should be able to identify and take care of that invalid data. That implies that if I boot into an external HDD with Snow Leopard on my older Mac, an OS that doesn't support TRIM, and if I delete files on my internal SSD, GC will move around the deleted "invalid" data, and when I reboot into ElCap from off the internal SSD, TRIM (if enabled) will clear those "invalid" (deleted) blocks and allow them to become usable (writeable) free space once again.

By the way, that Kent Smith talk says RAID is typically not supported by TRIM, but it is in fact supported on all RAID levels when using SOFTRAID, even the Lite version:

http://www.softraid.com/pages/features/softraid_application.html

I wrote SOFTRAID and asked if their $49 Lite version would be adequate to RAID 2 internal SSDs inside and older 2009 iMac and they said "yes."

if you want to save money just setup the raid with the yosemite disk utility like I did... You have to make a bootable pen drive, I did mine with disk maker x and boot up holding the ALT or what is known for mac the option button and once booted into it I used disk utility and setup the raid there then install yosemite and then upgraded to el capitan. Also with Raid you will have to save that pen drive because in raid config your SSD will not save a partition for recovery mode boot up only in a pen drive so keep that pen drive in a safe place always.....

when you boot to in recovery mode you choose the pen drive not the hard disk. I forgot to mention that.

There are other caveats to RAID as well:

OS X: "Some features of Mac OS X are not supported for the disk (volume name)" appears during installation - Apple Suppo…

So if you install a single SSD in the HDD slot of a 2009 iMac11,1 you would only get SATA-II 3G speed but you can use FileVault and the Recovery partition.

Correct you would get Sata 2 only and you would be able to use FileVault and it will have a partition for you to do boot recovery......

now when you do a striped raid and put the highest Kilobyte block for max speed you would get Sata 3 speed.

Fwtiw...

Just went through the same path: install a 500GB 850 Evo in my old 9,1 iMac, followed by a fresh install of El Capitan and guess what: negotiated speed is 1.5Gbps 😟

JDW1, can you confirm yours is in the 'main' HD tray?

Because mine is in the optical bay, so that might be an issue...

I have a WD Blue in the main tray, and sometime it negotiates at 1.5Gbps, sometime at 3Gbps. When it is at 3, it is faster than the SSD which is very frustrating.

Amedee, I put my Samsung EVO 850 500GB SSD into the main HDD slot of my iMac9,1. I did not use the optical drive slot.

So your experience and mine are PROOF that reports of the Samsung EVO working at 3G speeds in the iMac9,1 (early 2009) are ALL LIES AND DECEPTION.

But I also confirmed, along with one other person in this thread, that the same Samsung EVO SSD installed in the HDD slot of a 2009 MacBook Pro 5,5 works perfectly at 3G speeds. Since the MBP5,5 and iMac9,1 use the same exact NVidia controller chip, it make zero sense to me why the iMac9,1 cannot achieve 3G speeds. It makes no sense at all. And and it's a crying shame!

Well, I really don't know anymore...

I had to open it anyway, as it was stupid to leave an expensive SSD in it while the cheap WD Blue HDD was obviously faster as it was going full speed.

Since I had taken the HDD out as well to set set a jumper to force the 3Gbps, I decided to give the SSD a last chance and booted the system with the SSD in the HDD tray...

... and hooray, I have now a full 3Gbps on the SSD.

I rebooted - power off /on 10 times to be sure it was not a one time event, but it came up consistently at 3Gps.

I have no explanation, besides the fact that the optical drive bat has a special connector which is spitted in the tray, so maybe this connector type does not carry well SATA II or the tray degrades the signal.

I spent some time to 3D print a tray to hold the SSD in the HDD bay and rebuilt the machine.

I have now a 'fast' disk, but only 500GB storage 😕 . Maybe I'll put a 3'5 HDD in the optical bay to get some more.

So maybe they are not all liars... 😉

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