Looking for suitable 350W+ TFX PSU for my SFF mATX rig. Also, are SATA splitters/molex-to-SATA adapters okay?


I'm possibly looking to build the computer shown here for my semi-portable mid-range gaming and gamedev needs. Two SATA drives, probably the SSDs, will be placed on floor of case. As a SFF case, the site claims I need a TFX PSU.

Note that I couldn't find on that site the platter drives I will use, since they're older models from my previous computer. They're 3.5" 750GB Western Digital Caviar Blacks with 7200 RPM, 32MB Cache, and 3.0 Gbps, with model number WD7501AALS (

Mainly, I'm not sure how to navigate wattages and amperages. My research says that I should theoretically be able to use a 350W PSU, even though the video card says 400W minimum, if I make the 400w/12=33.33A minimum amperage using the tip on the sticky... but I'm not confident on this. I seem to be finding so much conflicting information everywhere.

So I thought I might ask this here: which PSU would you recommend for this case and setup, if any? Also, since I plan to use four drives (two pairs of mirror RAIDs), and most PSUs I found don't have enough SATA connectors, is it okay to use SATA splitters or molex-to-SATA adapters?

Thanks in advance.
4 answers Last reply Best Answer
More about suitable 350w tfx psu sff matx rig sata splitters molex sata adapters
  1. currently on my high end computer I have a molex to four sata power connectors and they are connected to four SSDs.

    If you need a TFX power supply it will be hard to find a 400w and mostly a 350w is what you'll find. You'll have to research the video card to see what amps it needs to function and then see if that power supply has the amps to output. This is from the Evga site;


    Minimum of a 400 Watt power supply.

    (Minimum recommended power supply with +12 Volt current rating of 20 Amps.)

    Total Power Draw : 55 Watts

    The In Winn 300w PSU has two rails rated at 16a each so the video card will only get 16a.
  2. Thanks for responding.

    I'm still wondering though, what if it has a single 12v rail? Should I divide that rail in two and assume that that card will only be taking from one of those two would-be rails, or should I take into consideration the other devices it could be connecting to, and subtract that from the total amperage from the single 12v rail?
  3. With a single rail PSU all the parts of the computer will be running off that single rail which most times is not a bad thing because that way there is no waste. An example is say you have a PSU that has 40a split on two rails (20a each) and one rail is connected to the video card that only needs 10a and the rest of the computer is running off the other rail , then there is 10a not available because the video card only needs 10a of the 20a. So a single rail means all the components get to draw from that total on the single rail.
  4. Best answer
    This would be perfectly fine:

    And what you said about the rails doesn't actually work that way. Almost all power supplies have transfers to utilize a different rail if needed.

    An overclocked system running a 750 will top out around 200w MAX. 350w gives you plenty of cushion and longevity, especially one built by SeaSonic.
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