5 ms·

Had to read this a few times before I got the meaning of the confusing title. The comparison is between a Mac with an Apple M series processor vs an Intel base

Had to read this a few times before I got the meaning of the confusing title. The comparison is between a Mac with an Apple M series processor vs an Intel based Mac, using either a Thunderbolt 3 vs a USB4 external enclosure for the (unspecified) SSD. The conclusion is that for the Intel Macs it does not make much of a difference, but for the M series there is a benefit from going USB4. The article is very light on methodology or actual data.

janandonly 3y ago
I did find the recommendation for the OWC Express 1M2 very practical, though.
- nickt 3y ago
  I’ve used the 1M2 with my own NVMe SSD, it’s very nice. Another good option is the Satechi USB4 NVMe SSD Pro Enclosure. Both are fast and reliable.
swiftcoder 3y ago
The conclusion is surely more along the lines that: - it's almost impossible to tell a priori what the performance will be, since manufacturers don't document their chipsets properly - a faster drive may be slower on an Intel Mac, due to falling back to USB3
coldtea 3y ago
>The article is very light on methodology or actual data. That's because it's not a benchmark, it's an explanation.
- logifail 3y ago
  > That's because it's not a benchmark, it's an explanation It's certainly an article that uses the word 'may' several times in the text, yet not once in its title.
  - adrianmonk 3y ago
    And? I don't see the problem. The title does include a qualifier: "good". If one product lives up to the potential that the technology (connection type) allows but another product doesn't, then I'd call (only) the first product "good".
ajross 3y ago
Really the takeaway is that the interop story for Thunderbolt/USB has turned into a big mess over the last decade[1], with way too many incremental revisions and standards changes that are supported by far too few actual devices, and combinations that are pretty much never tested. All those extra modes sound great on marketing slides, but the upshot is that consumers no longer know what they're getting when reading a spec sheet on Amazon. So you get articles like this purporting to say something about Apple products when almost certainly it's down to the lack of Intel Macs on a benchtop at whatever vendor packaged that drive. [1] In the last nine years there have been four independently issued USB standards and IIRC another two for Thunderbolt before the USB4 convergence. That's just not a reasonable landscape for a vendor to "support" in any meaningful way. Stuff that is correct at design time is obsolete by the time it ships, and the industry makes up for the churn by just skipping testing with the "old" stuff.
- izacus 3y ago
  And at the end the difference will be barely noticable and those articles are much ado about nothing.
  - deleted 3y ago
    [deleted]
- vetinari 3y ago
  There's no interop story between Thunderbolt and USB. Thunderbolt is packetized PCIe over USB-C connector in the alternate mode, that's all, similar to DisplayPort over USB-C. Even the cable is different than USB. With TB, you know exactly what are you getting. On the connector, there's a flash icon (meaning: thunderbolt) and a number (if > 3). That number says, which TB version it is. Even with USB4, there's no convergence. USB4 made TB alternate mode optional. USB4 is no guarantee, that you can use TB.
  - ajross 3y ago
    > With TB, you know exactly what are you getting. The article is literally detailing a Thunderbolt device that behaves differently when plugged into different macs, precisely because of the ambiguity introduced by the USB4 modes. "You know exactly what you are getting" is a story about a specification being unambiguously written. It doesn't say anything about what happens when you have dueling specs on the same port, which is the problem here.
dimask 3y ago
> for the Intel Macs it does not make much of a difference Not exactly, as it actually mentions intel macs do not support USB4, so USB4 enclosures will fall back to USB3 which is slower than TB3. The article is no less confusing than the actual topic. So the actual advice is TB3 for intel macs, USB4 for apple silicon.
rsynnott 3y ago
> The conclusion is that for the Intel Macs it does not make much of a difference, but for the M series there is a benefit from going USB4. It's worse than that; if you use a USB4 enclosure with an Intel Mac (or, really, just about any computer that's more than a few years old), it'll run at 10Gbit/sec (because USB3 is the fallback point, not Thunderbolt 3), but if you use it it with ARM Mac it'll run at 40Gbit/sec. If you use a Thunderbolt 3 enclosure instead it'll run at 32Gbit/sec in both cases. All bets are off if Thunderbolt 4. As always, USB, and associated standards like Thunderbolt, continue to be absolutely baffling. I think there had been the perception that USB4 would make all this a bit less confusing, but it very much hasn't.
- samatman 3y ago
  A lot of growing pains for sure. We've gone from "you have to find the cable which fits the port, and if you don't, you're out of luck" to "grab one of the 'universal cables' and see what happens when you plug it in". Although in practice I find it pretty easy to pick out power-only UBC-C, USB-only USB-C, and Thunderbolt USB-C, by the build quality/thickness of the cable. What's aggravating is devices (cheap ones) which use the USB-C port but will only charge from an OG 500mA charger. I keep those chargers in rotation as a result, but they're useless for any other purpose.
- moondev 3y ago
  I just ran a disk speed test on my 2018 Mac mini, connected to a USB4 NVME adaptor. NVME inside is a Samsung 970 pro (PCIE 3) Read 2692 MB/s Write 1774 MB/s System information claims the device as "USB4 NVME SSD Pro Enclosure" on the Thunderbolt 3 bus and not the USB bus
mort96 3y ago
Hector Martin has a different analysis: This article talks about TB4 vs USB4 but that's a red herring. This has nothing to do with USB4 and Intel USB4 compliant controllers have the same problem. The real reason Apple Silicon is faster is simple: Intel Thunderbolt controllers are *external* and bottlenecked on a PCIe 3.0 x4 link to the host, while Apple Silicon *embeds* the controllers right into the SoC, so there is no physical PCIe link anywhere. They connect directly to the much faster SoC fabric, so have no such bottleneck. I can't say whether he's right or not, but it sounds plausible.
- smith7018 3y ago
  I'd guess he's right. No one outside of Apple knows more about the inner-workings of the M series than Hector. For those that don't know, he's the main contributor and lead of Asahi Linux.
- toast0 3y ago
  I think it's reasonable to say a PCIe 3.0 x4 attached thunderbolt controller is bottlenecked by the host attachment; but that doesn't much matter if you're using PCIe 3.0 x4 mode (+/- interleaved display port). And it's also not limiting if you're in USB3 mode. There's only a real issue with capacity if you're using USB4, so I don't see how it's a red herring. Also, I've just read that Thunderbolt 3 has a hard reservation of 18 Gbps for display port data, limiting other data to 22 Gbps, so comparing TB3 to TB4 in pci-e mode will have that caveat as well.
  - jakobson14 3y ago
    inside the TB link there's no such thing as "3.0" or "x4" hector goes over this as well, but basically you've replaced all the lower (physical) layers of PCIe's networking stack. intel like to pretend that thunderbolt and USB4 just tunnel actual PCIe links unchanged (as if they're emulating everything down the PCIe lanes and PHYs), but they don't. PCIe over thunderbolt can run at whatever speed you please, limited only by the throughput of TB and the overhead of the remaining layers of the PCIe stack.
- 3y ago
leejoramo 3y ago
Regarding the lack of detail, this has to be taken in a bit of context. Howard Oakley -- the author of the site -- has many articles that go into great technical depth and ones that are more high level advice. While I would agree the article should link to more details, they are easy to find on the site. In fact, the author has written many benchmarking tools. Here are their tools related to disk and file system performance: https://eclecticlight.co/dintch/ https://eclecticlight.co/dintch/ It is a fair bet, they used their own benchmark tools. You can read other articles on the site that describe their work.
omgJustTest 3y ago
Someone who has a lot of ssd speed insight here: 1. problems are mostly thermal for external devices, ie if you have an enclosure that is not good for dissipating heat, and the device consumes Watts of power... it is unlikely you will see sustained performance 2. Not all USBC interfaces are alike, and getting USB2, USB3, USB Super Speed or USBC performance will vary based on a. the usb cable construction / performance spec, b. the usb-c cable orientation in the socket (yes they are symmetric, but not physically sometimes), c. the port you plug into, d. the orientation of the usb-c cable in the socket. If you are a person who desires more texture: 1. the real speed limit is how many lanes of PCI/CXL are extended to the controller on the USB bus, the controller on the device, 2. and the raw performance of the nand device, ie how many addressable bits are available per cycle &/or the amount of real-time recovery in LDPC that is successful in single pass ... ie optimization of throughput.

janandonly 3y ago

I did find the recommendation for the OWC Express 1M2 very practical, though.

nickt 3y ago
I’ve used the 1M2 with my own NVMe SSD, it’s very nice. Another good option is the Satechi USB4 NVMe SSD Pro Enclosure. Both are fast and reliable.

swiftcoder 3y ago

The conclusion is surely more along the lines that: - it's almost impossible to tell a priori what the performance will be, since manufacturers don't document their chipsets properly - a faster drive may be slower on an Intel Mac, due to falling back to USB3

coldtea 3y ago

>The article is very light on methodology or actual data. That's because it's not a benchmark, it's an explanation.

logifail 3y ago
> That's because it's not a benchmark, it's an explanation It's certainly an article that uses the word 'may' several times in the text, yet not once in its title.
- adrianmonk 3y ago
  And? I don't see the problem. The title does include a qualifier: "good". If one product lives up to the potential that the technology (connection type) allows but another product doesn't, then I'd call (only) the first product "good".

ajross 3y ago

Really the takeaway is that the interop story for Thunderbolt/USB has turned into a big mess over the last decade[1], with way too many incremental revisions and standards changes that are supported by far too few actual devices, and combinations that are pretty much never tested. All those extra modes sound great on marketing slides, but the upshot is that consumers no longer know what they're getting when reading a spec sheet on Amazon. So you get articles like this purporting to say something about Apple products when almost certainly it's down to the lack of Intel Macs on a benchtop at whatever vendor packaged that drive. [1] In the last nine years there have been four independently issued USB standards and IIRC another two for Thunderbolt before the USB4 convergence. That's just not a reasonable landscape for a vendor to "support" in any meaningful way. Stuff that is correct at design time is obsolete by the time it ships, and the industry makes up for the churn by just skipping testing with the "old" stuff.

izacus 3y ago
And at the end the difference will be barely noticable and those articles are much ado about nothing.
- deleted 3y ago
  [deleted]
vetinari 3y ago
There's no interop story between Thunderbolt and USB. Thunderbolt is packetized PCIe over USB-C connector in the alternate mode, that's all, similar to DisplayPort over USB-C. Even the cable is different than USB. With TB, you know exactly what are you getting. On the connector, there's a flash icon (meaning: thunderbolt) and a number (if > 3). That number says, which TB version it is. Even with USB4, there's no convergence. USB4 made TB alternate mode optional. USB4 is no guarantee, that you can use TB.
- ajross 3y ago
  > With TB, you know exactly what are you getting. The article is literally detailing a Thunderbolt device that behaves differently when plugged into different macs, precisely because of the ambiguity introduced by the USB4 modes. "You know exactly what you are getting" is a story about a specification being unambiguously written. It doesn't say anything about what happens when you have dueling specs on the same port, which is the problem here.

dimask 3y ago

> for the Intel Macs it does not make much of a difference Not exactly, as it actually mentions intel macs do not support USB4, so USB4 enclosures will fall back to USB3 which is slower than TB3. The article is no less confusing than the actual topic. So the actual advice is TB3 for intel macs, USB4 for apple silicon.

rsynnott 3y ago

> The conclusion is that for the Intel Macs it does not make much of a difference, but for the M series there is a benefit from going USB4. It's worse than that; if you use a USB4 enclosure with an Intel Mac (or, really, just about any computer that's more than a few years old), it'll run at 10Gbit/sec (because USB3 is the fallback point, not Thunderbolt 3), but if you use it it with ARM Mac it'll run at 40Gbit/sec. If you use a Thunderbolt 3 enclosure instead it'll run at 32Gbit/sec in both cases. All bets are off if Thunderbolt 4. As always, USB, and associated standards like Thunderbolt, continue to be absolutely baffling. I think there had been the perception that USB4 would make all this a bit less confusing, but it very much hasn't.

samatman 3y ago
A lot of growing pains for sure. We've gone from "you have to find the cable which fits the port, and if you don't, you're out of luck" to "grab one of the 'universal cables' and see what happens when you plug it in". Although in practice I find it pretty easy to pick out power-only UBC-C, USB-only USB-C, and Thunderbolt USB-C, by the build quality/thickness of the cable. What's aggravating is devices (cheap ones) which use the USB-C port but will only charge from an OG 500mA charger. I keep those chargers in rotation as a result, but they're useless for any other purpose.
moondev 3y ago
I just ran a disk speed test on my 2018 Mac mini, connected to a USB4 NVME adaptor. NVME inside is a Samsung 970 pro (PCIE 3) Read 2692 MB/s Write 1774 MB/s System information claims the device as "USB4 NVME SSD Pro Enclosure" on the Thunderbolt 3 bus and not the USB bus

mort96 3y ago

Hector Martin has a different analysis: This article talks about TB4 vs USB4 but that's a red herring. This has nothing to do with USB4 and Intel USB4 compliant controllers have the same problem. The real reason Apple Silicon is faster is simple: Intel Thunderbolt controllers are *external* and bottlenecked on a PCIe 3.0 x4 link to the host, while Apple Silicon *embeds* the controllers right into the SoC, so there is no physical PCIe link anywhere. They connect directly to the much faster SoC fabric, so have no such bottleneck. I can't say whether he's right or not, but it sounds plausible.

smith7018 3y ago
I'd guess he's right. No one outside of Apple knows more about the inner-workings of the M series than Hector. For those that don't know, he's the main contributor and lead of Asahi Linux.
toast0 3y ago
I think it's reasonable to say a PCIe 3.0 x4 attached thunderbolt controller is bottlenecked by the host attachment; but that doesn't much matter if you're using PCIe 3.0 x4 mode (+/- interleaved display port). And it's also not limiting if you're in USB3 mode. There's only a real issue with capacity if you're using USB4, so I don't see how it's a red herring. Also, I've just read that Thunderbolt 3 has a hard reservation of 18 Gbps for display port data, limiting other data to 22 Gbps, so comparing TB3 to TB4 in pci-e mode will have that caveat as well.
- jakobson14 3y ago
  inside the TB link there's no such thing as "3.0" or "x4" hector goes over this as well, but basically you've replaced all the lower (physical) layers of PCIe's networking stack. intel like to pretend that thunderbolt and USB4 just tunnel actual PCIe links unchanged (as if they're emulating everything down the PCIe lanes and PHYs), but they don't. PCIe over thunderbolt can run at whatever speed you please, limited only by the throughput of TB and the overhead of the remaining layers of the PCIe stack.
3y ago

leejoramo 3y ago

Regarding the lack of detail, this has to be taken in a bit of context. Howard Oakley -- the author of the site -- has many articles that go into great technical depth and ones that are more high level advice. While I would agree the article should link to more details, they are easy to find on the site. In fact, the author has written many benchmarking tools. Here are their tools related to disk and file system performance: https://eclecticlight.co/dintch/ https://eclecticlight.co/dintch/ It is a fair bet, they used their own benchmark tools. You can read other articles on the site that describe their work.

omgJustTest 3y ago

Someone who has a lot of ssd speed insight here: 1. problems are mostly thermal for external devices, ie if you have an enclosure that is not good for dissipating heat, and the device consumes Watts of power... it is unlikely you will see sustained performance 2. Not all USBC interfaces are alike, and getting USB2, USB3, USB Super Speed or USBC performance will vary based on a. the usb cable construction / performance spec, b. the usb-c cable orientation in the socket (yes they are symmetric, but not physically sometimes), c. the port you plug into, d. the orientation of the usb-c cable in the socket. If you are a person who desires more texture: 1. the real speed limit is how many lanes of PCI/CXL are extended to the controller on the USB bus, the controller on the device, 2. and the raw performance of the nand device, ie how many addressable bits are available per cycle &/or the amount of real-time recovery in LDPC that is successful in single pass ... ie optimization of throughput.