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Replace Fusion Drive with SSD on iMac 27" Late 2012?

M

Macintosh1984

macrumors 6502
Original poster
Dec 15, 2012
339
47
Hi!

I have an iMac 27" Late 2012 i7, 8GB RAM, Fusion Drive and NVIDIA 680MX, I'm quite satisfied, but I want to understand what margins there are to upgrade.

Do you think that replacing the Fusion Drive with only an SSD I can greatly improve the performance by counting the fact of SSD technology more up-to-date than in 2012?

Would you do even more, like 16GB RAM?

Thanks!
 
Are you able to do the work yourself to save labor costs? If so, a fast SSD and increase in memory should give you a big boost in speed and performance. You can check the procedure by going to www.ifixit.com and check out their instructions.
 
No, in the past I worked on assembled PCs, but with Macs of this type, I wanted to get experts to work.

Do you say that the performance is better because you did the same thing yourself or did you see others in my situation?

Or at the end do you advise me to buy an external Thunderbolt SSD? Would I get the same performance as an internal SSD by installing the operating system there above, or not? My Mac is Thunderbolt 1, unfortunately.

Or I can buy an external Thunderbolt SSD, free up Fusion Dive only for system and use Thunderbolt SSD for apps to increase performance, do you think?
 
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Id certainly upgrade the ram to at least 16gb. I have 40Gb of Ram in my 2019 27 inch iMac.

I have a 2Tb fusion drive as well in my 2019 iMac and the performance is very good(it comes with a 128Gb SSD). If you upgrade your Fusion drive to an all SSD drive then you will see speed improvement but is it worth the hassle? From what I heard, you can connect an EXTERNAL SSD drive to the iMac and install the Mojave operation system on that external SSD and basically use that external SSD drive as the main boot drive to avoid ever opening the iMac at all to replace the fusion drive. The Samsung T5 external SSD seems to be the most recommended external SSD drive.
 
I have a similar machine; a late '12 27 iMac i7 with 680MX graphics. I've been considering the same upgrade.

It sounds like there are a few options with SSD. One would be to replace the HD part of the Fusion drive with an SSD on the SATA bus. I'm not sure if it is possible to replace the SSD part of the Fusion drive with one larger drive on that bus though (PCIe?)

For now, I have a Samsung T5 SSD connected to it via USB 3. I have a startup volume on it I made with CCC. I haven't tested it, but it does seem very very fast, likely by a good margin over the old Fusion drive. You could get a little more speed using a Samsung X5 connected via Thunderbolt 1, but I'm not sure if the gain in speed would be cost effective over what the T5/USB bus has to offer.

Anybody know if you can upgrade the SSD in these machines using the original SSD bus? That sounds like it would be the ultimate upgrade.
 
I think I want to go to an external HD.

Can I ask you a small favor, to test your Samsung T5 SSD with Blackmagic Disk Speed Test? It's very easy and fast. Remember to target the Samsung T5 otherwise it will test your Fusion Drive!

Unfortunately, Samsung X5 is Thunderbolt 3.
 
"I think I want to go to an external HD."

Don't worry about what OTHERS get using BlackMagic.

An external USB3 drive should give you read speeds around 420-430mbps and writes in the 325-375mbps range (what you get depends on the drive make, model and size).

Samsung t5 or Sandisk Extreme would be a good choice.
Just plug it in and use it.
 
OK, I think I go for Samsung T5 or SanDisk Extreme SSD, anyway USB.

Samsung T5 with USB 3.1 Gen 1 get top performance, or better when connected to USB 3.1 Gen 2?

Last question, what about the situation about Thunderbolt 1 and double channel about simultaneous Read/Write data?
 
Macintosh1984 said:
OK, I think I go for Samsung T5 or SanDisk Extreme SSD, anyway USB.

Samsung T5 with USB 3.1 Gen 1 get top performance, or better when connected to USB 3.1 Gen 2?

Last question, what about the situation about Thunderbolt 1 and double channel about simultaneous Read/Write data?
Click to expand...

Since you’re connecting it to a 2012 iMac, your performance question is moot. Either the T5 or the Sandisk will be fast enough, but you are still limited to 5Gbps by the USB 3.0 ports on your iMac .

Thunderbolt SSDs are also moot at this point as there are no Thunderbolt 1/2 enclosures that I am aware of that can accommodate an m.2 blade, and it would be way more expensive than simply using a USB 3 drive as @Fishrrman suggested. Especially in light of the fact that Thunderbolt 1/2 hardware is being phased out over the next few years. The gain in performance with a TB1/2 enclosure and a SATA3 drive is definitely not worth the extra expense at this point, IMHO.

Good luck!
 
Macintosh1984 said:
Hi!

I have an iMac 27" Late 2012 i7, 8GB RAM, Fusion Drive and NVIDIA 680MX, I'm quite satisfied, but I want to understand what margins there are to upgrade.

Do you think that replacing the Fusion Drive with only an SSD I can greatly improve the performance by counting the fact of SSD technology more up-to-date than in 2012?

Would you do even more, like 16GB RAM?

Thanks!
Click to expand...

I was wondering what problem you are trying to solve. Where is your bottleneck? What workloads do you run? Otherwise, although most changes will improve the performance, you may not appreciate or notice it.
 
tbloomq said:
I was wondering what problem you are trying to solve. Where is your bottleneck? What workloads do you run? Otherwise, although most changes will improve the performance, you may not appreciate or notice it.
Click to expand...
The question is very simple, I would like to buy an external SSD with the best possible performance considering that I can only connect it with USB 3.1 Gen 1 or Thunderbolt 1.

You don't look for the best, price permitting?

All to avoid opening the iMac and replacing the Fusion Drive with a bigger and faster SSD.

If I had USB 3.1 Gen 2 I probably wouldn't even consider Thunderbolt.

With an external HD I can evaluate using it as a boot disk, or leave the operating system in the Fusion Drive and the Apps, without exceeding the 128GB SSD, and all other data on the external SSD.

So my legitimate doubts, but perhaps value for money better than Samsung T5 or SanDisk Extreme SSD.

I ask you last thing, TRIM question, on USB 3.1 Gen 1 can be activated or not? I know it's a good function, but I don't have clear what it actually entails, it seems to me longer life span and greater speed, or am I wrong?
 
Flag on the play.

I don’t care what you read on Tom’s. A T5 cannot support TRIM on any Mac since it must connect to a Mac via USB. Only an external that connects via Thunderbolt or eSATA can support TRIM. The T5 does not support either protocol. You can run sudo trimforce enable a thousand times but after it reboots and you check it, you’ll see that it was not enabled.

Apparently no one seems to know about the 2012 iMac.

Unlike the 2013 and later, both busses are SATA III even though one is a blade. Just put a big SSD in place of the HDD and that’s as fast as it can run — same as doing so to any earlier iMac. You will need the 2011 Temp sensor from OWC and the tape kit. A 3.5 to 2.5 adapter isn’t critical but recommended.

The blade in the 2012 was unique to that year. You can keep or toss it. If you want to install a second SSD in there, cable adapters exist that plug into the socket and let you stick a second SATA III SSD anywhere you can find room.

There is no need to tie the two back together into a fusion drive. Ok, if you installed a pair of 4TB 860 EVOs, you could make a single 8TB fusion drive, just as you can in a 2010 or 2011 27” iMac. Those are the only three years this is possible.

After you install the SSD, run sudo trimforce enable on the boot SSD to enable TRIM.
 
There are still a few Thunderbolt 1/2 enclosures and docks that let you drop in an SSD. Most run in the $150 range such as these (note that both are empty—you still have to supply the drive).

https://www.amazon.com/HighPoint-Dual-Bay-Thunderbolt-RocketStor-5212/dp/B00DJ3YEH0/ref=sr_1_4?gclid=Cj0KCQjw2v7mBRC1ARIsAAiw348C_tiUVaReAuzE-arvkEme6C7vlC7TRtFHqkdAdQRbu8-FJ06FSZgaAqHwEALw_wcB&hvadid=234000363356&hvdev=t&hvlocphy=9031936&hvnetw=g&hvpos=1t2&hvqmt=e&hvrand=12087265074473656381&hvtargid=kwd-316104483728&hydadcr=18038_9812679&keywords=thunderbolt+2+ssd+enclosure&qid=1558238048&s=gateway&sr=8-4

https://www.amazon.com/High-Point-R...sd+enclosure&qid=1558238310&s=gateway&sr=8-10

Even if you go this route, you still do’t solve the problem that the 2012s have: Heat. Get that spinning heat pump out of there. The 2012 iMac is Mojave compatible. You should be able to get a few more years out of these by replacing the HDD.

While you’re in thee, replace the NV RAM battery. It’s time.
https://forums.macrumors.com/threads/my-mac-has-gone-crazy-help-appreciated.2181619/#post-27372261
[doublepost=1558238950][/doublepost]
chscag said:
Which T5 are you referring to? My Samsung T5 supports Thunderbolt 3/USB-C and in fact I have it attached to my 2017 iMac Thunderbolt 3 Port.
Click to expand...
Don’t mean a thing. USB-C is a port, not a protocol. The Mac OS supports TRIM over PCIe, SATA or Thunderbolt. Period. No exceptions.

The Samsung T5 is USB 3.1 over USB-C and cannot support TRIM on a Mac. The X5 is Thunderbolt 3 over USB-C and does support TRIM.

There are a number of MacBooks with USB-C ports that do not support Thunnderbolt at all while others support TB1 or TB2.

Again, what Tom’s says about TRIM support over 3.1 may apply to Windows or Linux but doesn’t apply here.
[doublepost=1558240281][/doublepost]As you will see in these specs, the T5 does not support Thunderbolt.
https://www.samsung.com/semiconductor/minisite/ssd/product/portable/t5/

The claimed 4.9x speed advantage over an external HDD is real if that HDD is 5400 rpm. It’s only 3.8x faster if the HDD is 7200. I’ve tested this.

What they don’t say is that any SATA III SSD in a $20 external USB 3 dock is just as fast as the T5 when connected to a 2012 iMac since that Mac does not support USB 3.1.
 
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Samsung T5 MU-PA500B/EU is de SSD purchased.

So, no TRIM because USB connection.

I have also MacBook Pro (Retina, 13-inch, Early 2015) with Thunderbolt 2 (up to 20 Gbps). Is USB Type-C like Thunderbolt 2, so with this Mac I can get more speed thanks to the connection?

Do you recommend to format it in HFS+ or APFS?

Do you recommend to de-fuse the Fusion Drive to have the best control between 120 GB SSD and 1TB mechanic drive?
[doublepost=1558252970][/doublepost]
mikehalloran said:
Even if you go this route, you still do’t solve the problem that the 2012s have: Heat. Get that spinning heat pump out of there. The 2012 iMac is Mojave compatible. You should be able to get a few more years out of these by replacing the HDD.
Click to expand...
Look ... I do not notice high temperatures with the consequent increase in fan noise, except when I convert some videos to MP4 or play F1 2016. You believe it is more the heat of the CPU and the GPU or the mechanical hard disk.

Believe that on a practical level, without opening my iMac anyway, I can solve:
1) installing the game on Samsung T5
or
2) installing macOS on Samsung T5 making it become a boot disk
or
3) de-fuse Fusion Drive + by installing the game on Samsung T5

What do you tell me?
 
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HDDs are the source of the heat problems including those with the GPU in the 2009–2012 iMac. In 2013, Apple changed a slower, cooler HDD to help solve this.

You can remove the SSD from the T5. It’s the OEM version of the 760 or 860 EVO. You can also use it for external storage if you want.

Whatever you do with it, get an SSD and new battery in that 2012.

When the battery gets bad enough, it will cause video problems often misdiagnosed as GPU so replace that, too. Apple uses the heat resistant BR2032—you can find those on Amazon for $8 or so. With the HDD and its heat gone, a common CR2032 is perfectly fine—any drug store has them. With the screen off, changing the battery takes less than a minute.
 
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Incredibly satisfied with my new Samsung T5, even faster than my internal Fusion Drive, maybe because it's still full of data.

I formatted it in APFS making it also bootable.

I hope to continue to appreciate it with time.

At the passage of Apple's new macOS in September-October, I believe I will split the Fusion Drive.
 
I love my Samsung T5. I use it to make CCC backups and also made it bootable. The T5 cut my backup times in half over my spinning USB 3 hard drive. I just wish I had purchased another one when they were on sale at B&H Photo.
 
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