Making PSU lines (semi-) modular with Molex?

[Tuthmose]

Yet another question from my server re-wiring project. My new HDD hot-swap bays demand a whole bunch of Molex connectors instead of the SATA ones I’ve got, but I’m trying to keep the budget under control, so I’d like to work with the PSU I’ve got rather than buy a new one. Rather than cutting the factory-provided leads and soldering on the new leads that I need, I thought I might make a sort-of-modular deal by terminating very short stubs of the stock wires close to the PSU in Molex connectors, to which I could connect whatever lines I needed.

So, the question: is there any reason – resistance, inefficiency of Molex connections, etc. – that this would compromise the power in the connected leads? Are there connectors I should use instead of Molex for this, in the name of better power-transmission efficiency? I’m guessing not, since Molex adapters and such get used all the time, but I'm overly cautious (too many years of experience diving in first without all the info) and figured it couldn’t hurt to get some input before I got out the cutters and crimpers . . .

Thoughts pro or con are appreciated . . .

-Tuthmose

 

[Ultima99]

I'm no EE but I'd expect it to be fine as long as you do a good job of it.

 

[jojo69]

this is for HDDs right? they don't draw much, you should be fine, I would be more concerned if you were powering 7990s or something off it.

 

[Tuthmose]

The lines I'll be adding will be for:

9 HHDs - most are 2TB Caviar Greens, but I've got a pair of Caviar Black 7200rpms in there too
Three 120mm fans (one in each Hot-swap bay)
Two USB 3.0 PCI-E x 1 add-in cards.​

So, yeah, nothing like GPUs or other power-hungry stuff . . .

 

[Tsumi]

How about something like this?

 

[Tuthmose]

Tsumi, the problem I've got is that my PSU only has one 3-connector Molex line. While that extension would give me enough physical connectors, it would put virtually everything on the same set of wires. 9 HDDs, 3 Fans, a DVD burner, two USB 3.0 cards, and a card reader all on one set of 16awg wires seems like a disaster waiting to happen. Not to mention the wire-routing nightmare.

I've got to spread the load across several lines, but that means switching the two 3-SATA lines over to Molex. I think they do make a SATA to Molex adapters, but if I get six of those, I'm back to wiring chaos. Short of buying a new Modular PSU, I think modding the lines is the only way to do it safely and cleanly.

-Tuthmose

 

[Tsumi]

You can try contacting the manufacturer and seeing if they would supply you with the proper modular cables. What is your PSU specifically?

 

[jojo69]

I built an adapter out of the SATA port of a dead laptop HDD one time edit/zoiks...sorry about the size

 

[Tuthmose]

The PSU is just an inexpensive Corsair CX600. It was never modular in the first place, hence the issue. As the machine was just a server, I didn't go for anything fancy (read "expensive") when I first put it together. The project has evolved over time, though, and the addition of the Lian-Li hotswap bays have changed the power needs entirely.

This is only one part of the upgrade. The second part consists of an old Armor case I'm turning into a secondary storage tower, also hosting 3 hotswap bays, connected by way of Addonics port multipliers to the main server tower via the USB 3.0 cards. That box is going to be powered by a CX430 I've got lying in a box. Whatever mods I end up doing to the server's power supply I'm going to have to do to that psu as well, in addition to wiring a power switch into the 24 pin connector (since there'll be no mobo/cpu in the storage tower).

I *THINK* my Molex-semi-modular mod will do the trick and look clean to boot, but I just wanted to throw it out there in case I was overlooking something, at which point somebody could yell "Stop, you idiot! You'll put your eye out!"

-Tuthmose