As I am putting together the HW for my first home server I’ve encountered an issue which, after a bit of searching, has me a tad worried. The power supply I am hell-bent on using (FSP Twins PRO 500W) only comes with 6 SATA power connectors, whereas the total number of SATA drives will be 9 (5x spinning rust & 4x SATA).
I have seen quite a number of alarming posts/videos about how a Molex to SATA power reduction/extension is a bad, bad idea.
So I came here to ask the erudite community of L1Forums, how should I go about powering my drives?
You can get SATA power harnesses that turn one connector into 3-4. They’re more reliable than the molex ones. So long as you don’t exceed the amperage on your power supply, it should be fine. I’d run all the SSDs off of this as they use a lot less power than the spinning rust. You should try and spread the load across multiple rails on the power supply if that’s possible (usually only with fully modular units)
In my limited experience, my exactly 1/(one) fire in a PC was from a molex to sata adapter, which looked like below.
There are probably versions that do not cause fire
I had 3 of these in the computer when one burned, the others didn’t, but I switched to modular PSU’s so I could have more data connectors direct. The cable sets can cost half as much again as the supply…
Same for me, I’ve used 2 molex to sata adapters, one of which is the only cause of heat damage in a computer I’ve ever had. Fortunately no fire, but the connector melted itself.
It’s right that there are ones that don’t do this - the problem ones are exactly like the one picture, you can see the sata connectors are 1 molded piece of plastic formed around the wires. Due to the cheap manufacturing process, it’s common for individual wires to get caught in the molding and create shorts between the cables coming off the molex. Because they’re encased in plastic, it just gest hotter and hotter until it melts.
By comparison if you look at the molex connector, it’s a plastic housing that has the wires connected through and secure via the pins. This ends up being safer because you can see if the wires are going to short. There are sata connectors that are made the same way, most sata harnesses use these connectors, you can tell because they’re bulkier than the ones pictured above. These are much less likely to cause a problem, and can be used adapting from sata or molex, though I always prefer to adapt off of sata.
Basically what I am reading is, it boils down to cable quality.
Should I place my trust into a reputable brand, like for exampe a PP07-BTSBA from Silverstone?
That looks like a decent cable. It’s using the correct type of connectors, plus the use of braided cables generally indicates a higher level of attention/quality. I’d be fine using it.
I would personally be fine with molded connectors from a reputable brand (like cable matters).
Crimped connectors are basically as good as you can ask for (something which you could actually assemble yourself with a crimping tool). But a low quality vendor could probably manage to fuck even that up.
Picture references
Molded (may have problems, but no way to tell until it gives you smoke signals)
If you’re like me have and tons of HDDs, or multiple enterprise U.2 SSDs with potentially high power draw, then keeping in mind the total max and sustained amps the power supplying cables/connectors might experience is also a good idea. A molex connection can supply much more power than a sata connection. Adding a splitter on top of a sata connection can sometimes be done, but should generally be avoided.
This was probably 7 or 8 years ago, so I don’t remember exactly how long it was in use, maybe a year or two, but I’m guessing.
Fortunately I was in front of the system at the time, but I started the smell the classic burning plastic smell. Having heard horror stories of pc fires before obviously my first instinct was turn it off so I did. I don’t remember if I was doing anything particularly intensive on the system at the time.
It was on disassembly and inspection that I found the plastic housing on one of the sata powers had melted. I decided to upgrade my power supply to a fully modular one with more sata connectors as a result rather then risk it again
If the problem was there from the start, then yes, checking the cable with a multimeter before use or with a thermal camera during first use would be an option. But I’m not going to inspect my computers with a thermal camera once per week to catch failing cables. (And is once a week even enough - who knows?)
Looking at the video linked above the issue seems to be plastic and/or soldered connections failing over time, inside the cable, until things suddenly short out just enough (or the resistance gets high enough) to cause a lot of heat and a cascading failure. So quite possibly something you cannot detect at all until shortly before a catastrophic failure.
Realistically the only things that would push these connectors into failure over time are exaggerated heat cycles and strain. It is highly unlikely that the electromigration mentioned in the video is going to happen; the corrosion due to improper flux cleanup is still a possibility though, that is kind of the wildcard in all this that I wouldn’t know how to test for.
As long as you aren’t straining the cable, the only other common contributor to failure is going to be an elevated temperature, which should show up on a thermal camera (even small differences in the temperature or temperature distribution between different connectors would be an indicator). One good scan while the cable is under load should be enough to check it.
It’d be kind of interesting to test the adapters in an insulation tester; that might tell if some of the solder joints are “too” close together inside.
Maybe it’s because I’m using mine with SSDs but I’ve not had any issues in two years. I’m using the ketchup and mustard ones and so far everything seems to be going fine. I guess that if you’re not putting them under any electrical stress whatsoever they work.
