Is running an SSD from Thunderbolt as boot drive identical to having an internal drive?

[Lumonaut]

On a 2017 5k iMac. Could you use NVMe to get the same speeds? And if not how big of a difference would it be? I am not willing to pay Apple's exorbitant prices on SSD but may want to upgrade to this in the future if it is in fact an upgrade over using a Fusion drive.

 

[EugW]

I don't think Apple's SSD prices are that bad considering what you are getting. If you go with an external Thunderbolt 3 drive, it's a pretty clunky solution, and you'll probably end up paying even more because of the exorbitant prices of Thunderbolt 3 SSDs... unless you wait 2 years before you upgrade.

I don't think I could wait that long.

So, I got an iMac with 1 TB SSD. I think the sweet spot these days is 512 GB SSD, and then if that is not enough storage, you can get an external USB 3 hard drive.

 

[PortableLover]

Dells releasing some smaller tb3 drives with 2.6gbs. https://www.cnet.com/news/dell-performance-portable-ssd-ces/

500gb is $439

 

[maflynn]

I would first look to configure the internal drive to the largest capacity you can afford and then use external drives when that is inadaquate. I believe the current internal SSDs are very faster then external drives. I would also avoid trying to upgrade the internal drive as the risk of damage is high and personally not worth the risk (but that's just me).

 

[Fishrrman]

OP:

NO external drive you can buy now (or probably in the near future) is going to give you the performance that one of Apple's built-in SSDs will give.

No way.
Not even close.
End of story.

At the very least, spend $100 to special order the 256gb SSD in any iMac.
Then, add more USB3 storage as required.
A USB3 SSD (say, 500gb or 1tb) would probably do fine when you need it.

 

[EugW]

OP:

NO external drive you can buy now (or probably in the near future) is going to give you the performance that one of Apple's built-in SSDs will give.

No way.
Not even close.
End of story.

At the very least, spend $100 to special order the 256gb SSD in any iMac.
Then, add more USB3 storage as required.
A USB3 SSD (say, 500gb or 1tb) would probably do fine when you need it.

That is not quite correct. Some of the Thunderbolt 3 SSD drives that are coming out shortly are in roughly the same ballpark speed. But the point I was making earlier is they may actually cost more than just configuring your Mac appropriately. Thunderbolt 3 SSDs will be horrendously expensive, at least compared to USB 3 SSDs.

BTW, the drives are being shown at CES 2018, which is happening right now, so that's why you may not have been aware of them.

 

[danielwsmithee]

That is not quite correct. Some of the Thunderbolt 3 SSD drives that are coming out shortly are in roughly the same ballpark speed. But the point I was making earlier is they may actually cost more than just configuring your Mac appropriately. Thunderbolt 3 SSDs will be horrendously expensive, at least compared to USB 3 SSDs.

BTW, the drives are being shown at CES 2018, which is happening right now, so that's why you may not have been aware of them.

Also most of these drives aren't actually shipping until later this year April or later at reasonable costs. I expect within a year or two there to be lots of drives on the market and prices to drop substantially. Eventually External TB SSDs should only be a 10%-20% premium over a similarly sized internal M.2 NVME SSD. As essentially you are only adding a TB-PCIe bridge chip, and enclosure/packaging. The problem is flash chips are in very high demand, and I doubt production will ever keep up with supply so prices are going to continue to be high for the foreseeable future.

Especially with the added market silicon production demands that Spectre and Meltdown are going to cause in the market in the next 4-5 years.

I'd second the suggestion of getting the highest capacity internal SSD that Apple provides that you can afford. For now the sweet spot appears to be the 512GB model.

 

[itguy61]

I did this and lived with it for neatly two years on my last iMac. It was pretty easy to do and I just kept the drive behind the computer. It was so much faster than the internal HDD on everything. I just partitioned the drive using the proper options to make it a boot drive, cloned it with Superduper and made it the boot drive. was very well worth it.

The hard part is finding the housing, I have a seagate one portable back one I use and I found a Delock enclosure which is very compact. If you can find the housing you can do a 500gb drive for 250. Very good performance upgrade for the bucks.

 

[J.Gallardo]

On a 2017 5k iMac. Could you use NVMe to get the same speeds? And if not how big of a difference would it be? I am not willing to pay Apple's exorbitant prices on SSD but may want to upgrade to this in the future if it is in fact an upgrade over using a Fusion drive.

Almost everything said is correct... but they forget your question. YES, you should be able to use Thunderbolt3 to achieve comparable speed with an external SSD in near future.
You already can. The trick is surpass SATA bottleneck. You can buy -TODAY- PCIe based external storage. Or get an external dedicated enclosure & put ssd cards into. They offer similar speeds vs internal ssd. http://barefeats.com/hard226.html
This one looks wonderful (and expensive): http://www.sonnettech.com/product/fusiontb3pcieflashdrive.html
So it's also true that Apple prices are not so expensive... I've got internal 1Tb SSD; I made a special effort, but was tempted as you to postpone going FAST & SILENT.
Having the possibility to use that kind of storage in the future, due to supplied interfaces, is NICE.

 

[icemantx]

I have a late 2014 5k iMac and was thinking of replacing the 3TB Fusion with an external boot drive. Do you think I would notice a performance improvement over the Fusion with say a 500GB Samsung SSD on a Thunderbolt connection externally? I am just now out of warranty, so replacing the internal drives with a Samsung SSD is also an option, but not sure if it is worth it.

My main complaints are when you can notice the HDD is doing the work such as with iPhoto and looking through thumbnails watching them render...

 

[EugW]

I have a late 2014 5k iMac and was thinking of replacing the 3TB Fusion with an external boot drive. Do you think I would notice a performance improvement over the Fusion with say a 500GB Samsung SSD on a Thunderbolt connection externally? I am just now out of warranty, so replacing the internal drives with a Samsung SSD is also an option, but not sure if it is worth it.

My main complaints are when you can notice the HDD is doing the work such as with iPhoto and looking through thumbnails watching them render...

External Thunderbolt SSD would work and would be faster in a lot of stuff.

Are you really using iPhoto, or Photos?

 

[bxs]

On a 2017 5k iMac. Could you use NVMe to get the same speeds? And if not how big of a difference would it be? I am not willing to pay Apple's exorbitant prices on SSD but may want to upgrade to this in the future if it is in fact an upgrade over using a Fusion drive.

First, using an external media of any type to replicate the features offered by an internal SSD boot media is not possible. In general, the internal will always be superior in every way.

My advice is for you to purchase the largest internal SSD (no a Fusion drive - stay away from it IMO) you can afford. If the space on the internal SSD becomes exhausted down to road then look around for an affordable external SSD device.

Yes, you can boot from an external SSD but it will not be the same as for booting from the internal SSD. It maybe is not much of a difference (it will however be noticeable).

The Samsung T3 and T5 are very good units, are fast, dimensionally small in size and not that expensive.

 

[J.Gallardo]

The trick is surpass SATA bottleneck

When saying 500GB Samsung SSD... you mean a standard 2.5" SATA ? Then you'll be getting over 500Mb read/write, if using a USB 3.1 gen2... which uses usb-C connector.
Real Thunderbolt external cases are quite expensive, because they can use the much higher speed of PCIe (Thunderbolt special spec).
There's a lot of confusion about Thunderbolt , usb 3, usb 3.1 (gen1, gen2) and usb-C (that refers just to connector).
The SSD part of Fusion Disk will be faster, as said, for start up. Changing internal HD & installing a SSD is a good solution (if you can make it).
Having an external SATA drive for content & media is an easy solution. Everybody likes Samsung T5 (usb 3.1 gen2, thunderbolt compatible), but you can achieve similar speeds with cheaper SSDs.

 

[icemantx]

External Thunderbolt SSD would work and would be faster in a lot of stuff.

Are you really using iPhoto, or Photos?

I am using the Photos app, not iPhoto... A typo.

 

[EugW]

I am using the Photos app, not iPhoto... A typo.

How slow is it for you right now? The thumbnails in iPhoto don't appear instantaneously for me either - iMac i5-7600 with 1 TB SSD - but it's pretty fast.

However, I'm using mainly JPEGs. I'm not sure if it would be slower with RAW, unless there is a separate thumbnail library.

 

[h9826790]

On a 2017 5k iMac. Could you use NVMe to get the same speeds? And if not how big of a difference would it be? I am not willing to pay Apple's exorbitant prices on SSD but may want to upgrade to this in the future if it is in fact an upgrade over using a Fusion drive.

As a boot drive, you should not notice any difference. Even a SATA SSD via USB can boot / load apps with roughly the same speed. Those high speed SSD has very good sequential performance, but more or less the same random small files read performance as any other SSD.

For something like (un)zip, or copying very large files (to / from another super high speed drive), or loading a VM / very large library, etc. Those high speed SSD really shine. But for general use, they don’t make any difference, and if you do that via Thunderbolt 3 (with a proper adaptor), pretty sure even sequential speed won’t make any difference.

 

[wardie]

I use a cheap external USB3 enclosure with SSD in them, cost effective and speeds over 400 MB/s and it is bus powered hence turns on and off with the mac. As the above says for general use the small random read performance won’t change a lot spending more - but is vastly faster than equivalent HDD because of the way it works.
https://www.amazon.co.uk/dp/B00FCLG65U/ref=cm_sw_r_cp_tai_OGEwAbF8ZDEQW

 

[Fishrrman]

icemantix wrote:
"Do you think I would notice a performance improvement over the Fusion with say a 500GB Samsung SSD on a Thunderbolt connection externally?"

I've seen several posts like yours over the past few months here at macrumors.

And each and every time, I ask the poster to do the following:
1. Download Blackmagic Speed Test
2. Run it on your fusion drive
3. Post the results here.

Yet, no one seems willing to do so.

ONLY THIS can tell us whether the iMac you have will perform faster with an external boot drive.

About the best speeds you'll see from "an external booter" are reads in the 430mbps range and writes anywhere from 300-350mbps (depends on the drive and the size).

Are those numbers better than what you're getting now?
ONLY YOU can tell us this.

 

[h9826790]

icemantix wrote:
"Do you think I would notice a performance improvement over the Fusion with say a 500GB Samsung SSD on a Thunderbolt connection externally?"

I've seen several posts like yours over the past few months here at macrumors.

And each and every time, I ask the poster to do the following:
1. Download Blackmagic Speed Test
2. Run it on your fusion drive
3. Post the results here.

Yet, no one seems willing to do so.

ONLY THIS can tell us whether the iMac you have will perform faster with an external boot drive.

About the best speeds you'll see from "an external booter" are reads in the 430mbps range and writes anywhere from 300-350mbps (depends on the drive and the size).

Are those numbers better than what you're getting now?
ONLY YOU can tell us this.

That’s for sequential speed test, not good for reflecting OS operation. If Blackmagic speed test can reflect the real world OS responsiveness. Then a 4x HDD RAID 0 array can perform better than a SATA SSD. However, in real world, a single SSD will be 10x faster than a HDD RAID 0 array.

Use some other test that can show the 4K random read speed will be a much better benchmark for boot drive.

A HDD RAID 0 array can saturate a USB 3 connection, so around 500MB/s in Blackmagic test.

A SSD connected via USB 2 can only get about 50MB/s in Blackmagic test.

However, the USB 2 connect SSD can boot few times faster than the HDD array, because of its high IOPS, not sequential speed.

 

[icemantx]

icemantix wrote:
"Do you think I would notice a performance improvement over the Fusion with say a 500GB Samsung SSD on a Thunderbolt connection externally?"

I've seen several posts like yours over the past few months here at macrumors.

And each and every time, I ask the poster to do the following:
1. Download Blackmagic Speed Test
2. Run it on your fusion drive
3. Post the results here.

Yet, no one seems willing to do so.

ONLY THIS can tell us whether the iMac you have will perform faster with an external boot drive.

About the best speeds you'll see from "an external booter" are reads in the 430mbps range and writes anywhere from 300-350mbps (depends on the drive and the size).

Are those numbers better than what you're getting now?
ONLY YOU can tell us this.

Reads are 250-300 and writes are 600-630 roughly over several runs of Black Magic. Rendering thumbnails are not horribly slow meaning they paint on the screen within a few seconds as you scroll the page. It gets slower when the resolution is higher or thumbnails smaller.

Could be it is as good as it can be on a 3 year old iMac with 45,000 jpeg photos . Maybe I am asking too much of it.

 

[icemantx]

Any other thoughts on this as to whether or not upgrading the HD in my late 2014 5k iMac (changing internal to SSD or adding SSD external) is worth it?

 

[h9826790]

Any other thoughts on this as to whether or not upgrading the HD in my late 2014 5k iMac (changing internal to SSD or adding SSD external) is worth it?

It's worth 99% of the time. It won't give you any extra processing power. However, by removing the HDD I/O bottleneck, it should able to make you feel that your computer is much more responsive.

IMO, unless you love DIY, and have reasonable technique, adding external SSD should be a better choice. It gives you roughly the same OS performance, but won't risk to break anything. And you can keep the internal one as the backup boot drive + data storage.

 

[smirking]

Any other thoughts on this as to whether or not upgrading the HD in my late 2014 5k iMac (changing internal to SSD or adding SSD external) is worth it?

I would do it. You should install it internally if you're brave enough and are good at following directions.

I have a 2016 MBP now. I was previously on a mid-2012 MBP that I had upgraded by installing a 2TB Samsung SSD. That 2012 became quite a capable machine once I installed an SSD in it. By most practical real usage measures, my current MBP is only modestly faster.

My 2012 was handling image rendering in Capture One Pro just fine so it likely would have done quite well with Photos with the same images. SSD capacity sure is expensive, but I always try to get as much as I can afford. I'd rather spend a bit more money instead of waste a lot more time.

 

[icemantx]

I would do it. You should install it internally if you're brave enough and are good at following directions.

Since my setup is a 3TB Fusion Drive, would I just split the fusion drive, replace the HDD portion and keep the blade internal SSD already there and have 2 drives or fuse the 128gb blades and 1 or 2TB SSD in the iMac now?

 

[smirking]

Since my setup is a 3TB Fusion Drive, would I just split the fusion drive, replace the HDD portion and keep the blade internal SSD already there and have 2 drives or fuse the 128gb blades and 1 or 2TB SSD in the iMac now?

I'd have no idea. I didn't even realize that you could split a Fusion drive nor how you might be able to replace the HDD part of a fusion drive with an SSD. The only thing I can say is that if your goal is to not get beach balls when you're using Photos, you'll want enough SSD space to store all of your photos and do it with plenty of buffer space.