Sabrent Rocket NVMe 4.0 SSD

[smush]

Hi

Looking to expand the storage on my 2018 MacBook Pro with an external Thunderbolt 3 SSD and after going through the options I'm considering going for a DIY option. The NVMe drive that I see recommended a few times is the Sabrent Rocket NVMe 4.0 SSD but I was wondering, if I went for the regular PCIe 3.0 Sabrent Rocket NVMe would performance be the same? given that the MacBook Pro doesn't have PCIe 4.0 (I don't think?)

[Electronics Wizardy]

Yea performance will be very simmilar as you will be pcie 3 max with thunderbolt.

[smush]

5 minutes ago, Electronics Wizardy said:

Yea performance will be very simmilar as you will be pcie 3 max with thunderbolt.

Thanks for the reply. I note you say similar, so there is some slight benefit to going with the PCIe 4.0 NVMe despite the MacBook only supporting PCIe 3.0 ?

[schwellmo92]

3 minutes ago, smush said:

Thanks for the reply. I note you say similar, so there is some slight benefit to going with the PCIe 4.0 NVMe despite the MacBook only supporting PCIe 3.0 ?

There is no benefit going for the PCI-E 4.0 drive when you only have a PCI-E 3.0 interface. He is saying that the performance between the two drives is similar.

[Electronics Wizardy]

1 minute ago, smush said:

Thanks for the reply. I note you say similar, so there is some slight benefit to going with the PCIe 4.0 NVMe despite the MacBook only supporting PCIe 3.0 ?

What is your usecase for the ssd?

 

It should be very simmilar, they use different controllers, but the e16 in the 4.0 is basically the e12 with a pcie4 interface, but there are probably some small tweaks that may affect performance. But if performance is your main goal, there may be slightly faster drives depending on use case.

[smush]

16 minutes ago, Electronics Wizardy said:

What is your usecase for the ssd?

 

It should be very simmilar, they use different controllers, but the e16 in the 4.0 is basically the e12 with a pcie4 interface, but there are probably some small tweaks that may affect performance. But if performance is your main goal, there may be slightly faster drives depending on use case.

No particular use case I just want to expand my storage with a comparable or faster SSD than the internal one for as cheap as possible. I'd initially looked at the Samsung T7 SSD but from what I can gather it is slower than the internal SSD in the MBP. There are better performing SSDs such as the Samsung X5 but it works out more expensive than the NVMe DIY option which I was going to put inside something like this https://www.newegg.com/sabrent-ec-nvme-svr-enclosure/p/0VN-0036-00091

 

I'm open to suggestions/recommendations.

[Electronics Wizardy]

Just now, smush said:

No particular use case I just want to expand my storage with a a comparable or faster SSD for as cheap as possible. I'd initially looked at the Samsung T7 SSD but from waht I can gather it is slower than the internal SSD in the MBP There are better perfoming SSDs such as the Samsung X5 but it works out more expensive than the NVMe DIY option which I was going to put inside something like this https://www.newegg.com/sabrent-ec-nvme-svr-enclosure/p/0VN-0036-00091

 

I'm open to suggestions/recommendations.

so thats not a thunderbolt enclosure, its a usb one, so it will be much slower than the drives max.

 

I don't think the 2018 macbook pro supports 10gbs usb, so it will run at 5gbs speeds, same as normal usb 3.

 

 

Id get a much cheaper drive with that enclosure as your will be basically always bus limited, something like a 660p would be my pick, but a basic tlc drive like a sn550 would be better and sustained susquentical writes.

[smush]

5 minutes ago, Electronics Wizardy said:

so thats not a thunderbolt enclosure, its a usb one, so it will be much slower than the drives max.

 

I don't think the 2018 macbook pro supports 10gbs usb, so it will run at 5gbs speeds, same as normal usb 3.

 

 

Id get a much cheaper drive with that enclosure as your will be basically always bus limited, something like a 660p would be my pick, but a basic tlc drive like a sn550 would be better and sustained susquentical writes.

Doesn't Thunderbolt 3 support up to 40Gbs?

 

My bad with the link, the one that is recommended by this guy here: https://www.youtube.com/watch?v=CfNjnwfVLRs (which is where I got the recommendation for the pcie 4.0 NVme) https://www.amazon.co.uk/TREBLEET-HDDエンクロージャー-Hard-Drive-Enclosures/dp/B07N67P39W doesn't seem available but I did find this https://www.scan.co.uk/products/wavlink-ute01-external-enclosure-aluminium-thunderbolt-3-m-key-pcie-nvme-m2-2242-2260-2280-15w-usb-p

[Electronics Wizardy]

Just now, smush said:

Doesn't Thunderbolt 3 support up to 40Gbs?

it does, but that first linked one was not a thunderbolt enclosure, its a usb one. 

 

both of 2 listed enclosure are thunderbolt, but the first one isn't

 

What are you using the drive for? You are probably fine with a usb one, and it would be almost half the cost.

[smush]

11 minutes ago, Electronics Wizardy said:

it does, but that first linked one was not a thunderbolt enclosure, its a usb one. 

 

both of 2 listed enclosure are thunderbolt, but the first one isn't

 

What are you using the drive for? You are probably fine with a usb one, and it would be almost half the cost.

Mostly general tasks but I do use virtual machines sometimes as well as developing code that needs compiling. My main point being I will be using it alongside the internal SSD in the MBP so I would like to have the external be as close in speed to the internal. Perhaps I should clarify I'm not after the absolute cheapest option if there is a noticeable gain from something that costs more I'm all for it but using the PCIe 4.0 NVMe as an example if there is little to no benefit I'd go for the cheaper option

[Electronics Wizardy]

51 minutes ago, smush said:

Mostly general tasks but I do use virtual machines sometimes as well as developing code that needs compiling. My main point being I will be using it alongside the internal SSD in the MBP so I would like to have the external be as close in speed to the internal. Perhaps I should clarify I'm not after the absolute cheapest option if there is a noticeable gain from something that costs more I'm all for it but using the PCIe 4.0 NVMe as an example if there is little to no benefit I'd go for the cheaper option

probably then get something like a tlc pcie gen 3 x4 ssd, like a ex920, wd black, sabrent rock and the many others, they all preform reativity similar. THen make sure to get a thunderblt enclosure, the usb ones look simmilar.

[NewMaxx]

TB3 will be limited to 22 Gbps after encoding/overhead for a SSD. That is, 2.56 GiB/s (2.75GB/s). Keep in mind that transfers at low queue depth/threading will be slower than this. Internally the bridge chip (Alpine or Titan Ridge - you need the latter to support USB fallback) supports x4 PCIe 3.0 on the drive side, however there are still advantages to getting one of the 4.0 drives. This is because they have full-drive SLC caching (a SLC cache equal to about 1/3 the unused space) which could mean higher sustained write speeds over certain periods of time.

[NewMaxx]

On 6/6/2020 at 12:05 PM, smush said:

Doesn't Thunderbolt 3 support up to 40Gbs?

This is something a lot of people get wrong. Actually, TB3 can transfer more than 40 Gbps, however it can only do 22 Gbps of data (source, pg. 6). However this data bandwidth is after encoding and overhead. To explain the difference: 22 Gbps is 2.56 GiB/s (2.75 GB/s). With USB Gen3 2x2, which is 20 Gbps, you have 128b/132b encoding and then overhead, so actual throughput caps around ~1.9 GiB/s. This is why an OWC TB3 drive/enclosure lists a maximum speed of 2800 MB/s while the 2x2 WD P50 is rated at a maximum of 2000 MB/s. So TB3 ends up being 40% faster in reality despite only being 10% faster on paper.

[joevt]

On 6/6/2020 at 5:06 PM, NewMaxx said:

2.75 GB/s = 2816 MB/s

You are mixing units - and doing it backwards. 22 Gbps = 2.75 GB/s = 2750 MB/s = 2.561 GiB/s. Binary units (such as GiB) should not be used for data transfer numbers anyway.

 

I think the OWC number of 2800 MB/s is just 2750 MB/s rounded up. They don't show benchmarks so it's hard to say where they got that number from. The 22 Gbps limit of PCIe traffic over Thunderbolt 3 might not be a hard limit. Newer CPUs and controllers may allow slightly better performance. I saw a benchmark of 2978 MB/s for a Thunderbolt 4 controller in a YouTube video.

 

On 6/6/2020 at 5:06 PM, NewMaxx said:

So TB3 ends up being 40% faster in reality despite only being 10% faster on paper.

Right. The TB3 number of 22 Gbps for PCIe data does not include any Thunderbolt and PCIe overhead that is required to transmit that amount of data. The USB gen 2x2 number of 20 Gbps, which is actually 19.39 Gbps after considering the 128b/132b wire encoding, still includes USB protocol overhead. It is interesting to note that the 40 Gbps number of Thunderbolt takes into account the 64/66b wire encoding of Thunderbolt (Thunderbolt transmits 41.25 Gbps on the wires). USB4 will use 40 Gbps on the wire but will use 41.25 Gbps when supporting Thunderbolt 3.

 

[NewMaxx]

I corrected the numbers with some relevant links but I'm quite aware of the decimal/binary difference. I answer a lot of posts and make flubs but this thread is over two months old, the point stands that TB3 would be significantly faster.