How Big Of A PSU Is Needed For A Trading Computer?

Discussion in 'Hardware' started by Scataphagos, Feb 17, 2011.

  1. Bottom Line....

    1. Most trading rigs run at near idle, regardless of how many apps are open at once.

    2. Even with a mid-range gaming video card, normal power usage is <150W... so 3, workstation video cards will be that or less.

    3. Therefore, any 400W or greater PSU should suffice.... but should not buy el-cheapo PSU. If your PSU fails, it might completely destroy your rig. Not worth it to take additional risk of all your hardware and data to save a few $$ on a cheap PSU. (Usually when a PSU fails, it either simply shuts down or refuses to power up... like a burned-out light bulb. Sometimes, however, they fail spectacularly... in a hail of flames and sparks. When that happens, every component of your rig is at risk.),2849.html#xtor=RSS-182&foo=What Do High-End Graphics Cards Cost In Terms Of Electricity? 02-17-2011
  2. The interesting thing is a PSU of 400W and a PSU of 600W-700W are not that different in price, about $50 to $90. (And I haven't seen anything lower than 400W at the store) Some are higher in price. I always thought: why worry about $30-$40. Save myself some hessle for not getting enough juice for the box. And imagine the trouble of having to re-assemble everything - provided that the motherboard and cards are not fried.
  3. A common misunderstanding is that a 900w power supply is consuming 900 watts continuous.

    Whether you have a 500w psu or a 900w psu, your system will consume however much power it takes to run the system. A larger than necessary psu is fine. Too small of a psu is trouble.

    Each psu has its efficiency and other factors.

    Efficiency is greatest towards the top end of the power rating of the psu.

  4. Another common misunderstanding is that running 4-8 monitors requires a big power supply.

    1. Monitors have their own power supply, so they're not a drag on the computer's PSU.

    2. For graphics, the computer is only concerned with the graphics card... and for trading rigs, they need not draw much more than 25W each.. maybe only 10W each.

    Bottome line... for a trading rig, any decent brand 400-500W PSU will suffice. Or, find a good 650W with a rebate. You don't need to spend $150 on a PSU, and you SHOULDN'T buy one for $20.
  5. I've spoken about this at length in previous threads in this Forum years ago . . . there is a lot more to know about power supplies than mere watts.

    You need to understand that there are 3 RAILS in a PSU that support the individual componentry of your Computer . . . the +3.3V, the +5V, and the +12V rails.

    PC Power & Cooling builds some very robust PSU's with 7-year warranty's:
  6. I put a 650W Corsair into a recent build. It's plenty, even with a video card that on overclocking pulls 319W. The video card has it's own power connector for a dedicated fan, so it pulls a bit more juice when on turbo.

    (The whole system pulls 319W - not the vid card alone)
  7. jprad


    I suggest you take a look at the efficiency and acoustic noise graphs in this link then reconsider your viewpoint on ideal P/S efficiency...
  8. Thanks for the link jprad. Unfortunately the article was posted in 2008 and I didn't find the current models of CPU chip (e.g. Intel i7-930, chipset X58) and other newer NVidia chips (e.g. the GS series). From what I gathered the i7 series processors seem to take up a bit more powers than the other lines.

    Just to play it safe and not worrying about the cost difference, I got the PSU around 650W to 700W. The one I picked up, as recommended by the store's consultant, delivers 52A max current at 12V which (was said) is useful when CPU is a max load under overclocking condition.
  9. jprad


    Unfortunately, Landis is dead-on, a lot of people don't "get" power supplies and I'd bet that applies to the "consultant" you spoke with.

    Worse when it comes to CPUs...

    Believe it or not, but an i7-980x CPU only consumes 15w more than an archaic P4 Prescott core; 130w compared to 115w.

    And, compared to your average NVIDIA video card, that i7 can be less than 1/2 to as little as 1/3 the load.

    As for the article, sure, power supply models as well as CPUs will change, but the salient point is where you want to be on the efficiency and acoustic curves when you're running an average computing load.
  10. I see 3% difference from max efficiency to the efficiency at max rated power on your charts. 85% efficiency on an AC/DC power supply unit is expected efficiency whether in a computer or otherwise.

    The acoustic noise charts are meaningless.

    I guess I don't understand why you're asking me to reconsider my viewpoint.
    #10     Feb 20, 2011