Hi Alec,
glad to answer your questions. Since I consider the CP117 of great importance, I have taken about an hour to answer your questions profoundly. I’ve taken time to read through USB4 / Thunderbolt specs again because USB4 contains various characteristics mattering for the performance of high performance U.2 NVMe SSDs over USB4, in particular as now U.2 SSDs are shipping with PCIe 4.
Please find my replies below.
Best regards
Sam
Q1. Given the features of USB4, what’s your opinion about it? Does it suit your need?
In the light of fact that USB4 and Thunderbolt defacto have the same specs, USB4 would be equivalent to Thunderbolt and thus suit all needs for high performance NVMe SSDs. With 40Gbit/s (≈ 5 GB/s) all available PCIe 4 NVMe SSDs can unfold 100% of their possible data throughput with USB4.
"Is USB4 same as Thunderbolt?
Thunderbolt 4 and USB4 have the same specs, but Thunderbolt 4 is more reliable with tighter minimum specs. Both can drive dual 4K displays, transfers data at 40Gbps, and provide power to charge a laptop. But USB4 has lower minimum specs, and makers can choose not to implement all the features to minimize costs."
UBS4 Protocol Tunneling
"PCIe tunneling, meanwhile, is something we hear about less often with USB4. That's partially because the feature is optional, except in USB4 docks. PCIe tunneling makes USB4 a candidate for the likes of external storage drives."
From my understanding, the performance of U.2 SSDs (or M.2 SSDs) depends on the PCIe tunneling functionality of USB4. So if a USB4 CP117 can transfer SSD data over the PCIe tunneling protocol, NVMe SSDs will deliver exactly the same performance and latency as they would under Thunderbolt.
But with the UASP protocol, from my understanding, the native performance of NVMe PCIe 4 SSDs can not be saturated at all as UASP was developed a couple of years before the first NVMe SSDs arrived in the market.
https://en.wikipedia.org/wiki/USB_Attached_SCSI
Q2. Do you care about the choice of materials, e.g. aluminum, plastic etc.? Or do you prioritize function performance and cost effectiveness?
One of the obstacles of Thunderbolt based adapters or external Thunderbolt SSD enclosures was, that they were substantially more expensive than USB adapters/enclosures. This only partly was because of the royalty fees Intel in the past asked for Thunderbolt.Hence, for the GoToMarket of the USB4 CP117 I would suggest a good balance between materials and cost effectiveness.
1) Durable plastic is as good as the more expensive aluminum.
2) In the light of fact that the U.2 SSDs will be connected on the fly to the USB4 CP117, the better thermal conductivity of aluminum over plastic is irrelevant. The USB4 CP117 is an adapter not an enclosure.
3) The U.2/U.3 2.5” format was developed because it allows for substantially better heat dissipation than M.2. This means that U.2 SSDs connected to the USB4 CP117 don’t need additional heat dissipation measures.
Q3. Is it important for you to have a hard drive that is fully protected and protected from direct contact heat? Or is small size, lightness and portability your top priority?
1) The form factor illustrated for CP117 is just ideal as it allows for on the fly swap of U.2 SSDs. In production environments (e.g. TV production) it is important that SSDs and the USB4 CP117 adapter can be connected/disconnected on the fly.
2) Moreover, U.2/U.3 SSDs are already well protected with their own enclosure (unlike M.2 SSDs which are “blank bars”). So, there's no need for an incremental USB4 CP117 enclosure.
Again, here we see that U.2 form-factor SSD are advantageous over M.2 SSDs. Actually, M.2 SSDs only make sense for Notebooks or PCIe cards where available space is scarce. In all other scenarios U.2 form-factor SSDs are favorable, not to speak of the much higher capacity they can house when compared to M.2 form-factor SSDs.
Q4. Is there a need for additional cooling of the drive (expected long hours of use)
As explicated above, for U.2 form-factor SSDs I don’t see heat issues requiring additional cooling. I suggest you take a 15.36 TB or 30.72TB U.2 SSD from Micron, Samsung, KIOXIA or Western Digital and you will experience that they won’t get heat issues when connected to a Mac or PC over the USB4 CP117- even for hours.
Only in a dense storage enclosure with many U.2 SSDs mounted side by side, active cooling (fans) is required for U.2 SSDs.
Q5. Do you care about the type and accessories of the power supply, e.g. DC, Type-C? Or would you prefer a Type-C power port without a charger for environmental reasons?
From my understanding U.2/U.3 form factor SSDs consume much comparable power to S-ATA 2.5” SSDs. So power being delivered over USB4/USB C (up to 100 watts) will be more than sufficient.
As an analogy: All external 10Gbit Ethernet adapters these days too are powered over the USB-C port rather than providing an external power supply.
Q6. Are there any other specifications you would like to consider before purchasing? For example, weight, noise, etc.
1) U.2/U.3 SSDs connected to the USB4 CP117 (as illustrated above) will be completely silent.
2) Plastic will be lighter than aluminum. Also, plastic in winter never gets as cold as aluminum because it has a much lower thermal conductivity. Anodization helps to limit the thermal conductivity of aluminum but why use aluminum when robust (e.g. ABS) plastic can be very durable too.
If you have any other thoughts, concerns or suggestions besides the above, please let us know.
I think for the moment the above annotations cover for the most part.