2017 27" Imac Samsung T7 SSD Boot Drive

[dago5252]

I recently made a bootable drive with a Samsung T7 SSD on my 2017 27" iMac. I formatted the T7 with APFS and cloned with CCC. All went well, but my read speeds on the SSD has dropped according to Black Magic. I have the 2TB fusion drive and was trying to improve responsiveness. There is also almost no difference in boot time between the two HD's. Any suggestions on getting a better experience with the T7?

Mac HD- 485.7 Write/ 2051.4 Read
T7 HD- 804.7 Write/ 906.6 Read

Thanks

 

[mdgm]

The T7 is limited by the USB technology used.

If you want to get better speeds you need a TB3 SSD e.g. the Samsung X5.

Not only is TB3 much faster than USB it also supports TRIM.

To get 2051.4 Read it must have been reading from the SSD portion of the Fusion Drive. Reading from the HDD would be much slower than from the T7.

 

[dago5252]

The T7 is limited by the USB technology used.

If you want to get better speeds you need a TB3 SSD e.g. the Samsung X5.

Not only is TB3 much faster than USB it also supports TRIM.

To get 2051.4 Read it must have been reading from the SSD portion of the Fusion Drive. Reading from the HDD would be much slower than from the T7.

Thanks for the info. I will return the T7 and look at the X5 or making a SSD.

 

[mdgm]

So essentially your T7 SSD will be slower if the Mac can solely use the SSD portion of the fusion drive to do something, but will be much faster if the internal hdd would need to be extensively used using the Fusion Drive. So benchmarks reading/writing not much data can be a bit deceptive.

A fast TB3 SSD would give comparable performance to solely using an internal SSD without the risk of breaking the iMac.

Some would use a TB3 SSD to boot from and a cheaper drive like the T7 for any extra storage needed or for TM backups.

If you can return the T7 and get the X5 or a different TB3 SSD that would be good. Note you must make sure that it is a TB3 SSD. Look at the specs and the speeds that are reasonably obtained. A fast TB3 SSD should get well over 2000MB/s. Some slower portable ones may get speeds around 1500MB/s, still significantly faster than USB.

Some USB SSDs may be advertised as having a TB3 compatible port or something like that when they are not actually TB3.

 

[dago5252]

So essentially your T7 SSD will be slower if the Mac can solely use the SSD portion of the fusion drive to do something, but will be much faster if the internal hdd would need to be extensively used using the Fusion Drive. So benchmarks reading/writing not much data can be a bit deceptive.

A fast TB3 SSD would give comparable performance to solely using an internal SSD without the risk of breaking the iMac.

Some would use a TB3 SSD to boot from and a cheaper drive like the T7 for any extra storage needed or for TM backups.

If you can return the T7 and get the X5 or a different TB3 SSD that would be good. Note you must make sure that it is a TB3 SSD. Look at the specs and the speeds that are reasonably obtained. A fast TB3 SSD should get well over 2000MB/s. Some slower portable ones may get speeds around 1500MB/s, still significantly faster than USB.

Some USB SSDs may be advertised as having a TB3 compatible port or something like that when they are not actually TB3.

Great info & Thanks. The iMac seems to be a little more snappier on the T7. Would the below links work for a DIY SSD? They claim to support TB3.

M.2 NVME SATA SSD Enclosure Adapter, Tool-Free USB C 3.1 Gen 2 10Gbps to NVME PCIe M-Key(B+M Key) Solid State Drive External Enclosure Support UASP Trim for SSD Size 2230/2242/2260/2280

M.2 NVME SATA SSD Enclosure Adapter, Tool-Free USB C 3.1 Gen 2 10Gbps to NVME PCIe M-Key(B+M Key) Solid State Drive External Enclosure Support UASP Trim for SSD Size 2230/2242/2260/2280

www.amazon.com

Western Digital 1TB WD Blue SN550 NVMe Internal SSD - Gen3 x4 PCIe 8Gb/s, M.2 2280, 3D NAND, Up to 2,400 MB/s - WDS100T2B0C, olid State Hard Drive

Put NVMe power at the heart of your PC for lightning-fast, ultra-responsive performance. The WD Blue SN550 NVMe SSD can deliver over 4 times the speed of our best SATA SSDs. Whether you're working, creating, casual gaming or processing large amounts of data, take advantage of this powerful intern...

www.amazon.com

 

[mdgm]

That would give similar performance to the T7. 10Gbps is the bottleneck for the T7 limiting you to a theoretical 1000MB/s (in practice less than that). TB3 supports up to 40Gbps. Some of the faster TB3 drives will do about 2800MB/s.

The enclosures that are TB3 are more expensive.

If you want to use your own SSD, then options to consider would include:

• Trebleet: https://www.amazon.com/TREBLEET-Thunderbolt-Enclosure-Thunderbolt3-Drive/dp/B07YHRW654
• Sabrent: https://www.amazon.com/Thunderbolt-Certified-Tool-Free-Enclosure-EC-T3NS/dp/B08FT59SB6
• OWC: https://eshop.macsales.com/shop/envoy-express/thunderbolt-3

etc.

Some bus powered options like the OWC Envoy Express are limited to about 1500MB/s (from tests they did with the iMac Pro so actual performance with your Mac may be lower than that).

Some enclosures support faster speeds than others.

Note that not all drives may be compatible with a particular enclosure. See e.g. https://forums.macrumors.com/thread...osure-sabrent-2tb-rocket-issues-help.2268762/

 

[Rusty33]

Thanks for the info. I will return the T7 and look at the X5 or making a SSD.

Just wondering how the OP went with this? Did you find any performance improvements with the X5 or via the DIY route? I'm also looking to upgrade a 2017 iMac, but with a 5400RPM drive (no fusion). I expect that ANY SSD will offer a dramatic improvement. This thing is barely usable these days...