Windows 7 Bus Powered Drive Seen as Self Powered Drive?

[Maxxwire1]

I recently installed a Sabrent 4-Port USB 3.0 Hub (HB-UM43) which I assume should show up in device manager as a bus powered hub since it has no external power supply. It is listed as having a 900 mA draw and is currently powering a pair of 500 mA USB 3.0 flash drives and is recognized as a self powered generic hub in device manager.

I have spent many hours searching the internet trying to understand how it could be that a non-powered USB hub can show up as a self powered hub in device manager without any answers and I am hoping that I can find an explanation here.

 

[ChatGPT]

The distinction between self-powered and bus-powered USB hubs in Device Manager can sometimes be unclear, especially when a device is listed differently from what is expected. Here's an explanation to clarify why your Sabrent 4-Port USB 3.0 Hub (HB-UM43) is showing as a self-powered hub even though it is bus-powered:

Understanding Self-Powered and Bus-Powered Hubs:​

1. Self-Powered Hub:
   • A self-powered USB hub has an external power source to provide power to connected devices. These hubs are designed with an additional power adapter to ensure that all connected devices receive sufficient power without overloading the host device.
   []Bus-Powered Hub:
   • A bus-powered USB hub draws power from the host device (like a computer or laptop) to operate and provide power to connected peripherals. These hubs rely on the USB host for power, which is limited to a specified amount depending on the USB standard (e.g., USB 2.0, USB 3.0).

     Reasons for the Listing:​

     Here are a few reasons why your bus-powered Sabrent USB hub may be listed as a self-powered device in Device Manager:
   []Power Reporting:
   • Some USB hubs may report themselves as self-powered devices even if they are bus-powered. This reporting can sometimes be misleading in Device Manager.
   []Firmware Information:
   • The information displayed in Device Manager can be based on how the hub's firmware reports its power source, which can be a fixed setting or a general descriptor.
   []Compatibility Reporting:
   • The listing in Device Manager might be a generic or default description based on the hub's design and how it is recognized by the system. This basic description might not always accurately reflect the actual power configuration.

     Checking Actual Power Draw:​

     To verify the power draw and configuration of your Sabrent USB 3.0 hub accurately, you can consider the following steps:
     • Use third-party software or utilities to monitor the power usage of individual ports and devices connected to the hub.
     • Contact Sabrent support or check the product documentation to confirm the power specifications and reporting behavior of the USB hub.
     Given these factors, the reporting of your bus-powered USB hub as a self-powered device in Device Manager is likely due to the way it is identified by the system and how it reports power information. As long as the hub is functioning correctly and providing adequate power to your connected devices, you should not face any operational issues caused by this reporting discrepancy.