Hello UUGear Support,
I'm planning a multi-drive storage setup using your MEGA4 4-Port USB 3.0 PPPS Hub:
https://www.uugear.com/product/mega4-4-port-usb-3-ppps-hub-for-raspberry-pi-4b/
The system will use a Raspberry Pi 5 to control multiple MEGA4 hubs, with four Samsung T7 portable SSDs connected to each hub. The system is intended to run continuously, so reliable power delivery and avoiding unexpected USB disconnections are important.
I've reviewed the MEGA4 specifications and your recent forum response regarding supplemental power, USB-C power negotiation, and host-side power draw. I'd appreciate your recommendations on the following points before purchasing the power supplies.
1. Recommended power supply for four Samsung T7 SSDs
Samsung specifies that the T7 consumes less than 4.5 W under normal operating conditions. Four drives could therefore consume approximately 18 W, equivalent to 3.6 A at 5 V, before accounting for the MEGA4 itself and any transient loads.
Would you recommend a regulated, fixed 5 V / 5 A power supply for each MEGA4 when powering four Samsung T7 SSDs simultaneously?
Alternatively, would a 5 V / 4 A supply provide sufficient capacity in practice, including simultaneous drive startup and sustained read/write activity?
2. Specific power supply and cable recommendations
Could you recommend a specific power supply manufacturer and model that you have tested and confirmed to work reliably with the MEGA4?
Ideally, I'd like a supply with the following characteristics:
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Regulated 5 V DC output.
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Up to 5 A continuous output current.
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Overcurrent, overvoltage, short-circuit, and thermal protection.
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A compatible USB-C output and suitable cable capable of delivering the required current with minimal voltage drop.
If possible, please provide direct product links for both the recommended power supply and cable.
3. USB-C input and power delivery compatibility
Your forum response explains that the MEGA4 does not implement USB Power Delivery negotiation, and that the 5 A rating of its USB-C connector describes the connector's current-carrying capability rather than the current guaranteed by the connected supply.
Could you confirm whether the MEGA4 can reliably draw up to 5 A from a conventional fixed-5-V USB-C power supply without USB-PD negotiation?
Would a USB-C power supply rated for 5 V / 5 A require any particular cable configuration, or would you recommend a different connector or supply arrangement?
In particular, would you advise against using a 45 W or 65 W USB-C laptop charger for this application?
4. Power-loss behavior and protection
Your forum response explains that, if supplemental power disappears, the MEGA4 can draw power from the Raspberry Pi's USB bus, potentially exceeding the host's available USB current budget.
For a continuously running setup, is there a recommended way to minimize this risk and prevent unexpected drive disconnections if a supplemental power adapter fails or is accidentally disconnected?
I understand that the standard MEGA4 does not automatically disable downstream port power when supplemental power is lost. I'm interested in any supported hardware recommendations or precautions you suggest for this situation.
5. Raspberry Pi 5 compatibility
Although the MEGA4 product page identifies the Raspberry Pi 4B, I intend to use it with a Raspberry Pi 5.
Are there any known compatibility issues or additional power considerations when operating the MEGA4 with a Raspberry Pi 5, particularly when multiple hubs and bus-powered SSDs are connected?
6. Recommended configuration for multiple hubs
My intention is to provide a dedicated supplemental power supply for each MEGA4, while powering the Raspberry Pi 5 separately.
Would you consider this the preferred configuration for reliable continuous operation with four Samsung T7 SSDs per hub? Are there any additional precautions you would recommend regarding power sequencing, cable selection, or simultaneous startup of multiple drives?
Thank you for your assistance. I'd prefer to use a power supply and cable combination that you have tested and can recommend, rather than risk compatibility or power-delivery problems by choosing an adapter based solely on its advertised wattage.
I look forward to your recommendations.
Best regards
MEGA4 accepts 5V supplemental power via USB-C and does not support USB-PD negotiation. It supports up to 5A total output current, with a maximum of 2.5A per port, provided the power source is capable of supplying sufficient current.
A 5V/5A power supply would offer more headroom than a 5V/4A one for your estimated load. However, the actual power requirements, including peak loads, need to be verified in your setup. The advertised wattage of a USB-C PD charger does not necessarily indicate its available current at 5V without PD negotiation.
MEGA4 can work with Raspberry Pi 5, although the included U-shaped USB adapter does not align perfectly due to the different USB port positioning.
If supplemental power is lost, MEGA4 may draw power from the Raspberry Pi instead. It does not automatically disconnect downstream loads in this situation.
Using a separate supplemental power supply for each MEGA4 is a reasonable approach. However, we cannot recommend a specific third-party power supply or cable, nor guarantee the reliability of your complete storage system.
Selecting suitable components and validating the setup under actual operating conditions, including power interruptions, is the responsibility of the system integrator.