Any consumer-grade SFX-L PSUs that support PMBus / SMBus?

First time builder here! Putting together a NAS/homelab and I was inspired by the L1Techs collab video with GamersNexus which used the ASRock Rack X470D4U2-2T as the base for what I felt was a pretty attractive system (video titled: “Building the Ultimate DIY NAS on AMD, Ft. Level1Techs, Unraid, & ZFS (Part 1/2)”)

I decided to work within a mini-ITX case and ordered the newer mITX version of the board, the ASRock Rack X570D4I-2T (hopefully will arrive in a few weeks).

While looking through the manual for the motherboard, I noticed a port labeled PSU_SMB1 for a PSU SMBus to monitor the operation of the power supply (possibly via the PMBus protocol?)

Screen Shot 2020-08-04 at 8.38.07 AM

My mITX case limits me to an SFX / SFX-L PSU. I did some searching and could not find an SFX/-L PSU (or any consumer-grade PSU for that matter) that mentions SMBus support or has a 5-pin connector that matches the spec above. At this point I’m guessing this connection only shows up on server-grade PSUs (like Artesyn, Delta, TDK-Lambda as linked on the PMBus website).

I suspect this board was likely designed with rack mounted use in mind which I expect would open the door to a number of PSUs with SMBus but I’m wondering if anyone knows of any consumer-grade SFX-L PSUs that support the SMBus connection on the market. I’d be just as happy to learn that none exist (as I suspect) so I can end my search as I would be if one does :sweat_smile:.

Any help is greatly appreciated!

Probably wont find that in any SFX PSU thats a consumer psu that wont have the features. You board will still give you info on power delivery tho through the ipmi port if i am not mistaken, so not really a big deal.

Thanks, that’s what I thought. I was also hopeful that I could get the info via IPMI but I just looked through the ASRock Rack IPMI Configuration User Guide and found that it mentions that in order to display power source information the PSU does need to support PMBus (I’m betting this is where IPMI gets its power info from) so I think I would be missing out on some monitoring features without one.

It’s not a huge deal. Rewatching the build on the Gamers Nexus channel, it looks like Wendell and Stephen also passed up on it based on the “N/A” output on the PSU lines in the H/W monitoring section of the BIOS.

Skimming through the video, I think they used a Silverstone SFX-L PSU (which I am pretty certain doesn’t support PMBus).

What hardware are you running? I have the 700w SFX-L as well as 2 EVGA 650w units. the price on the EVGA is way better then seasonic atm

$116.99 for 650w modular gold (seems to be oos atm tho F )

Thanks for the recommendations! That Fractal PSU and the comparable one in the Seasonic Focus SGX line are both on my shortlist. Here’s my rig:

Case: Silverstone CS01-HS
Motherboard: ASRock Rack X570D4I-2T
CPU: AMD Ryzen 7 3700X
Graphics: NVIDIA Quadro P1000
Memory: 2x32GB DDR4-2933 PC4-23400 ECC SODIMM 2Rx8 Memory by Nemix Ram
Storage: 4x Seagate 5TB BarraCuda 5400 RPM 128MB Cache SATA 6.0Gb/s 2.5" 15mm (with the possibility of adding 2 more down the line) plus 1-2 SSDs and an M.2 NVMe that I haven’t chosen yet
CPU Cooler: Noctua NH-L9i
PSU: To Be Determined

I’ve been building with low power consumption and quiet operation in mind so currently thinking 500-600w would be more than enough to feed the system with a little headroom for upgrades down the line. If I abandon the search for PSUs with PMBus support that limits me to just a few options, especially given the PSU shortages going on right now.

After reading through the reviews on Tom’s Hardware and looking at the data from Cybernetics, I decided to go with the Fractal Ion SFX-L 500W Gold (available for $99.99 on newegg at the time of posting).

After some time has passed now, have you dabbled around the interwebs to see if such a PMBus/SMBus PSU ATX or SFX PSU exists?
I’m putting together a similar build in a full tower chassis and would be nice to have that communications feature to the MoBo.

@raven_tech_djent I was unable to find an SFX-L PSU that supported the protocol and haven’t looked around since deciding on the Fractal Ion SFX-L 500W Gold in early August. I did limit my search to the SFX-L form-factor at the time so if you’re working within a less restrictive case you may have better luck!

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while looking at this same topic today, I found that corsair actually makes some in their HXi series, along with a $4 cable to connect them|-Parts/PC-Components/Power-Supplies/AXI-I2C-800mm-PMBus-Cable/p/CP-8920117

these mind you are ATX PSUs so a bit bigger than SFX ones, but it’s something

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