.png)
Sparkle TD-8140 USB4 Travel Dock Review & Teardown (Intel Hoover Ridge JHL8140 dock)
Introduction
At Computex Taipei and other tech conferences earlier this year, new USB4 chipsets from RealTek and Intel were announced. The Sparkle TD-8140 USB4 travel dock is the earliest available Intel JHL8140-based product. JHL8140 (code-named Hoover Ridge) is a cost-reduced version of Intel’s JHL8440 (Goshen Ridge) Thunderbolt controller chip which forgoes downstream 40Gb/s PCIe functions but adds the ability to operate without an external power supply.
Full disclosure: While this is not a sponsored post, the product showcased was provided at no cost for evaluation purposes. Products received in this capacity are destined for teardowns, future device interoperability testing, and/or charitable donations.
Product Specs
Host Interface: USB4 40Gb/s with 85W PD charging
USB-C 3.x Gen2 10Gb/s w/DP Alt mode (8K@30Hz)
DisplayPort 1.4 (8K@30Hz)
HDMI 2.0 (4K@60Hz)
2x USB-A 3.x Gen 2 10Gb/s (5V x 0.9A)
3.5mm TRRS combo audio
Gigabit Ethernet
USB-C DC power input port (100W PD)
80cm detachable USB4 cable
Dimensions 105x105x33 mm
Unboxing & Physical Characteristics
Unlike the earlier Sparkle products I reviewed (TDX-120GD TB4 dock and TCX-230DA external GPU), the TD-8140 is housed in a simple plastic shell rather than anodized aluminum. While it has a pleasant weight and doesn’t feel cheap, it is not a premium design like the other Sparkle products.
Functional Testing
Monitors
Although there are three receptacles on the dock that can support monitors (DP, HDMI, and USB-C) only two of these can be used at any one time. So if you use the USB-C port for a monitor, either the DP or HDMI port will be disabled. This is a limitation of the Intel JHL series controller chips.
Up to 2x 4K60 or a single 8K30 monitor is supported; I only had 1440p and 1080 monitors available to test and I found no video issues.
Although not specifically disclosed in Sparkle’s materials, the dock is limited to a single monitor output when used with older USB-C laptops – again a limitation of the JHL controller so this was expected.
Power
The hub works with or without an external power supply. Without a power supply, you can exhaust the available 15W from a Thunderbolt laptop port or ~7.5-10W from USB-C laptops quickly. For example, if you attempt to charge a cellphone and run an external hard drive, you may run out of power. In this scenario, it seems that the dock just switches off one of the USB ports. On some budget docks, the whole device can reset instead which can be rather disruptive. Below I’ve gathered some photos I took while testing the most common scenarios. In this testing, I was surprised that my new Plugbale 240W EPR USB-C power meter with OLED screen was able to monitor power while also passing along the 40Gb/s signal. Very impressive!
I tried connecting the hub to some older laptops that only supported USB-C, not Thunderbolt or USB4. The hub functioned OK, but my laptop (Surface Book 2) only outputs ~10 watts on the USB-C port, so the power available to devices plugged into the hub was even more limited than the Thunderbolt scenario.
With a USB-C power supply plugged in, the dock worked well. The dock accepts 100W PD and did not exceed 85W sent to the laptop. With a 60-watt charger I was able to confirm that laptop power was limited to ~45W so power de-rating is done correctly.
Curiously, I was only able to get ~2.5W from each of the USB A ports rather than the advertised 4.5W. Perhaps the claimed 4.5W is shared between the two ports? I will need to re-test this more carefully to double-check the results.
To-do: deeper comparison of JHL8140 vs VL830 power consumption
USB device performance
I did not test USB device performance, but I had no issues with an external SSD, keyboard, mouse etc. All seemed to work OK.
Other notes
When I daisy-chained the Sparkle hub after my external Thunderbolt 3 GPU, I noticed inconsistent results with the hub resetting whenever I plugged or unplugged a device. I suspect this was a power issue with my eGPU but I’ll have to investigate further.
The Dock is shown in the Thunderbolt control center, but is missing from the built-in Windows 11 USB4 domains page [Settings – Bluetooth & device -> USB -> USB4 Hubs and Devices].
Teardown
PCB Details
[click for hi-res photos]
Component Topology
Functional chips:
Supporting chips:
Analysis
Sparkle makes good use of PCB real-estate with the top side fully packed with chips and other components. The rear is sparsely populated with just the Realtek Ethernet chip, 5 flash chips for firmware, and some mosfets – components that don’t get very hot and don’t need a heatsink.
There are 3x 10-pin headers with some of the pins routed to the FlashROM chips which are probably used for firmware programming and testing. In addition, there are two un-populated headers (a 4-pin and a 5-pin) next to the C-Media audio chip. These are probably used to attach a speaker, microphone, and volume/mute buttons for the Conference Dock model showcased at Computex:
Similar to the other Sparkle devices, each ports gets its own filtering and protection diodes. But the overall design lacks robust EMF shielding seen in some of my other device teardowns. In the case of the Sparkle desktop TB4 dock and eGPU, the chassis was metal, but the TD-8140 is just plastic. I don’t want to mislead – with good PCB design, you don’t necessarily need shielding to meet minimum requirements – but adding shielding can’t hurt and makes the device more premium. Even just adding sticky-metal foil to the inside of the plastic case and attaching a conductive foam to make contact with the PCB ground could help. But maybe Sparkle’s PCB is just excellent and wouldn’t improve with any of that – I have no way to test it with my equipment.
After examining the signal traces coming from the JHL8140 chip, I thought it looked familiar, so I compared it to the Sparkle TDX-120GD which has the JHL8440 chip. The chip size is identical as is the signal routing. Are these actually the same chip? Its possible, but Intel makes it clear in the MDDS documentation that the JHL8140 is 0.226 grams and the JHL8440 is 0.45 grams so something is different internally. I don’t think Intel is simply fusing off the PCIe logic on these – its probably a different design but re-using the functional blocks from the JHL8440.
Conclusion
Overall, I like the Sparkle Dock. There is only one product I can compare it to directly: the Hyper HD583 USB4 Mobile Dock.
Sparkle TD-8140 vs Hyper HD583
Which is better?
The Sparkle feels like a higher quality product but is also twice the size and weight. Inside, ~40% of the volume is empty space. At first, I thought this was because they would use the same chassis parts for the TD-8140S Conference dock model and just cut a hole in the top for the speaker. But looking carefully at the photos from Computex, the Conference dock is even thicker. So I’m not sure why Sparkle left so much empty space. I think it would be better to slim-down the dock and add air vents for the heatsink. Afterall, most business-class laptops are less than 20mm thick but this dock is 33mm so it would put a bulge in anyone’s laptop case.
As for features, the docks are similar. On both products, I think including 1Gb/s Ethernet instead of 2.5Gb/s is a big miss. The BOM cost increase of the better Realtek RTL8125 chip is small and the rest of the PCB remains the same so I don’t know why these products must go with the dated RTL8153.
Because of the MST chip in the Hyper, it is the better choice for legacy USB-C laptops while the Sparkle is better for Mac and Thunderbolt-equipped PCs. The USB-C port with DP alt mode on the Sparkle makes it a more versatile and future-proof product as you can daisy-chain another dock that can consume USB+DP, connect to a USB-C monitor directly, or even a VR headset. No such luck with the Hyper.
So can I recommend the Sparkle Dock? At $179.99 list price it is rather expensive compared to the $139.99 Hyper dock. There are a handful of other vendors planning to launch JHL8140-based products in October/November so hopefully pricing will drop below $150. In any case I’ll be keeping watch and will update the master Thunderbolt 4 / USB4 hub/dock list accordingly.
Update: Both the Sparkle and Hyper have been heavily discounted – below $138 for the Sparkle and down to $77 for the Hyper.
Appendix
Some excerpts from the JHL8140 spec that leaked last year – I’m not sure what I wanted to say about these, but here they are in case of interest:
Comments