Heisen
Herald
Request Advice: How to power 4 SSDs connected to RPI
- Thread starter bornlibra23
- Start date
imran_chennai
Forerunner
This should serve well. I'm using a 4-port version to power 2.5" HDDs
Heisen
Herald
2025, update.
With usb to sata adapters like these, they have DC power jack for external power.
Here you can use DC barrel jack splitter like this one.
This is as easy as it's gonna get. One DC adapter will power all.
With usb to sata adapters like these, they have DC power jack for external power.
Here you can use DC barrel jack splitter like this one.
This is as easy as it's gonna get. One DC adapter will power all.
bornlibra23
Explorer
badwhitevision
Forerunner
Those DC Jacks are 12v only. ie.) For 3.5 inch HDDs.
You might not find any benefit for 2.5 HDDs or SSDs.
Cheers
You might not find any benefit for 2.5 HDDs or SSDs.
Cheers
bornlibra23
Explorer
Heisen
Herald
Good call, I will test and report, if we use 5V adapter will the SSD switch to external power or not.
@Heisen any chance you can provide me with the source files? I wanted bare metal for the power, and USB-C inputs.
@bornlibra23 some points you may want to keep in mind when specifying your system design, if I may.
The RPis are usually internally sharing the bus, so the concern for bandwidth is overblown. As a matter of fact most platforms use a hub on each pair of outputs, but there's still sufficient sharing going on internally.
Moreover, the Pi cannot saturate a pair of 5gpbs connections because of low internal throughput. Even a Pi5 cannot manage more than 800MB/s transfers on its PCIe connector.
The biggest advantages of SSDs are random access, and they usually remain the same regardless of bus connection because there is sufficient latency overhead in a USB 2.0 connection to allow for fast random access, even though sequential is slower.
Most non-DRAM drives slow down to native flash rates in large sequential writes once the SLC cache runs out, I've seen as low as 35MB/s which is below USB 2.0 bandwidth.
Lastly, flash is far more susceptible to failure than magnetic media, and less likely to be recovered for every sort of fault. Even a badly damaged magnetic platter can be recovered with some effort.
@bornlibra23 some points you may want to keep in mind when specifying your system design, if I may.
The RPis are usually internally sharing the bus, so the concern for bandwidth is overblown. As a matter of fact most platforms use a hub on each pair of outputs, but there's still sufficient sharing going on internally.
Moreover, the Pi cannot saturate a pair of 5gpbs connections because of low internal throughput. Even a Pi5 cannot manage more than 800MB/s transfers on its PCIe connector.
The biggest advantages of SSDs are random access, and they usually remain the same regardless of bus connection because there is sufficient latency overhead in a USB 2.0 connection to allow for fast random access, even though sequential is slower.
Most non-DRAM drives slow down to native flash rates in large sequential writes once the SLC cache runs out, I've seen as low as 35MB/s which is below USB 2.0 bandwidth.
Lastly, flash is far more susceptible to failure than magnetic media, and less likely to be recovered for every sort of fault. Even a badly damaged magnetic platter can be recovered with some effort.