Slow External SSD?

[hakr100]

Good morning. I have a new MBA and new Samsung SSD Model T7. Almost nothing on either drive. External SSD is plugged directly into the MBA. I am getting 650 MB/s on writes with the Samsung and 694 MB/s with reads. These seem low to me. Comments, suggestions? Thanks!

 

[Fishrrman]

Do you have another Mac with which you could try the drive?

Actually, read speeds of 694MBps aren't all that bad -- although not near the upper end of what it might deliver.

Also... did you erase/reformat the drive before using it?
What format is it in now?

 

[hakr100]

Both my 2020 iMac and my new MBA are APFS. The external Samsung SSD runs about 15% faster on my iMac. I erased and formatted it before using it. A Samsung tech told me this morning that the drive should be running faster and maybe that Apple hadn't optimized its software for these drives. I have no idea about that.

 

[hakr100]

So, allegedly the ports on my new MBA are Thunderbolt and I still think I should be getting higher than 650 MB/s on writes and 694 MB/s with reads with my new Samsung SSD Model T7 when plugged into the computer with the cable Samsung included. Any clues?

 

[Fishrrman]

Can the connecting cable be changed?
If so, have you tried another cable?

 

[hakr100]

Can the connecting cable be changed?
If so, have you tried another cable?

Yes, I have tried other cables. Made no significant difference. The Samsung T7 uses USB-C so 10 Gbps should be do-able. Samsung says "Transfer massive files within seconds with the incredible speed of USB 3.2 Gen 2 on the T7. The embedded PCIe® NVMe™ technology facilitates sequential read/write speeds of up to 1,050/1,000 MB/s, respectively, making the T7 almost twice as fast as the previous T5 model."

I talked to Samsung about this, and it suggests that Apple needs to "modify" its code to accommodate the higher speed drives. I have no way to test whether a different T7 drive or a different brand would perform better.

 

[hakr100]

Well, I just plugged my Samsung T7 into my 2020 iMac and got 900 MB/s write and 916 MB/s read, significantly faster - about one-third faster -than the same drive on my new MacBook Air. Again, with the cable supplied with the drive by Samsung. I wonder why.

 

[Tenkaykev]

I’m in the market for an SSD for my M1 Air so this is quite a useful thread. I’m undecided between the Samsung T7 and the Sandisk Extreme. I think on paper the T7 is the faster drive, equivalent to the Sandisk Extreme Pro, but I’m not sure if that reflects real world performance.

 

[hakr100]

Well, my dataset is pretty small, but I think my test with the iMac, where the T7 performs better, probably is or is close to real world performance. I'd be very interested in the numbers you get with your M1 Air and an external SSD.