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Power Supply Question, 38w?

By Darrenbilly
Jul 27, 2009
  1. I did a check to see how much power my computer needed and apparently it needs 38w. Is this right? It has a max output of 230volts and i am looking to get a new video card, i know i will need a new psu you to sufficiently power it, i might get a 400. Would this be enough? Thanks
     
  2. strategic

    strategic TechSpot Paladin Posts: 1,020

    Where di you see the 36w at?
    For a typical desktop, you're probably looking around 300-400w, but then again, if you tell us the computer specs, you could get an answer with better accuracy :)
     
  3. Tmagic650

    Tmagic650 TS Ambassador Posts: 17,244   +234

    Darrenbilly is confused :confused: It is probably a 380 watt supply. The 230 volts is a switched setting for Europe with 115 volts for the US. These are AC input, not output voltages
     
  4. red1776

    red1776 Omnipotent Ruler of the Universe Posts: 5,219   +157

    Hi Darrenbilly,
    was it the Antec psu calculator that you used by chance? when you go to that page the calc is at 38w by default. i wonder if you forgot to hit the calculate button? using your specs there, i did an approx watt usage on your machine and came up with 160w.(with no video card) and then you need to add 30% to whatever needed wattage you come up with. try it yourself here
    http://www.antec.outervision.com/PSUEngine

    as far as 400w psu being enough, that soley depends on the card you are looking at getting.
     
  5. Tmagic650

    Tmagic650 TS Ambassador Posts: 17,244   +234

    Those power supply calculators were designed by power supply manufacturers to get unsuspecting newbe computer builders to spend big bucks for much overrated power supplies...
     
  6. Darrenbilly

    Darrenbilly TS Enthusiast Topic Starter Posts: 161

    Hmm?

    I thought that you were right for a minute, but when i hit the calculate button, believe it or not, it said 34w.... This is the site i used http://extreme.outervision.com/PSUEngine
     
  7. red1776

    red1776 Omnipotent Ruler of the Universe Posts: 5,219   +157

    when i used it Tmajic it was pretty accurate
    darrenbilly, your cpu alone uses more than 38w, you must not be using it correctly, here look at this this is just with a P4 entered, and nothing else.
     
  8. Tmagic650

    Tmagic650 TS Ambassador Posts: 17,244   +234

    To my surprize, It actually told me that I needed a 380 Watt supply... When I upgraded my video card 3 months ago, I went with a 500 Watt
     
  9. Rick

    Rick TechSpot Staff Posts: 4,573   +65

    A Pentium 4 3GHz uses nearly three times that amount... Just the CPU! :haha:

    So I just wanted to confirm that number is most definitely not correct. However, the 400W you suggested will definitely be enough. Even many high end systems peak at less than 300w, but power supplies are often less than 85% efficient and it's nice to have some headroom.
     
  10. red1776

    red1776 Omnipotent Ruler of the Universe Posts: 5,219   +157

    and i would add that if you get a really powerful graphic card you may need a 450-550w psu, but short of that a good 400w will suffice as Rick said.
     
  11. Darrenbilly

    Darrenbilly TS Enthusiast Topic Starter Posts: 161

    :)

    The whole reason i asked is because i knew it was totally weird. Who fancies looking through this list and telling me if it will all work together? Thanks for all of your time and comments, suggestions etc.
    Also, antec say i need................... 34w View attachment 51040
     
  12. Darrenbilly

    Darrenbilly TS Enthusiast Topic Starter Posts: 161

    :)

    The whole reason i asked is because i knew it was totally weird. Who fancies looking through this list and telling me if it will all work together? Thanks for all of your time and comments, suggestions etc.
    Also, antec say i need................... 34w View attachment 51040
    List:
    Corsair 4GB (2x2GB) DDR2 800MHz/PC2-6400 XMS2 Memory Kit CL5 1.8v

    Gigabyte GA-MA770-UD3 770 Socket AM2+ 7.1 Channel Audio ATX Motherboard

    Casecom Shiny Black Mid Tower Case with Front 120mm Red LED Fan - No PSU

    LG Electronics Blu-Ray & HD-DVD-Rom Combo 16x DVDRW Black SATA - Retail Box With Software

    Gigabyte 9400GT 1GB GDDR2 DVI VGA HDMI Out PhysX and Cuda ready PCI-E Graphics Card

    Samsung EcoGreen F2 1TB Hard Drive SATAII 32MB Cache - OEM

    Arctic Power 700W PSU - With PCI-E, 4x SATA, 20+4, ATX12V, 8pin +12V Connectors - Retail Boxed

    AMD Athlon 64 X2 7750 2.7 GHz Socket AM2 2MB Cache Retail Box Processor

    Thanks
     
  13. red1776

    red1776 Omnipotent Ruler of the Universe Posts: 5,219   +157

    Darren, once again your not doing something right. i went to the antec psu calculator and entered only Your P4 @ 3.0Ghz (see above attachment) and it gave me 102w just for that. you need to hit the 'calculate' button after you enter all of your components.
     
  14. red1776

    red1776 Omnipotent Ruler of the Universe Posts: 5,219   +157

    some advice darren,
    that will work, but, to much psu, not enough graphic card. i dont know anything about Arctic power, but 700w for 43 quid sounds suspicious, spend the 43 quid on a corsair , antec or OCZ 450-500 watt. if you want to do any gaming of any modern titles, that graphic card wont cut it.
     
  15. Darrenbilly

    Darrenbilly TS Enthusiast Topic Starter Posts: 161

    Oops

    I feel like a bit of a twonk now... I didn't realise you had to input your own info! I thought it detected it and worked it out for you :( My actual wattage is: 151w!! Hurray (ME=*****)

    Why is that GC no good? I understand about the psu, but i didnt think you could have too much power? How about the rest of it, would it all work together if i get a 400-450w antec and what about a GC? Thanks red1776
    Please note the PC setup in my profile is not for the one i am on! It is for another PC
     
  16. red1776

    red1776 Omnipotent Ruler of the Universe Posts: 5,219   +157

    the GC is okay as long as you dont expect to do any gaming whatsoever, if you can tell me what you expect from GC i would be happy to recommend one.
     
  17. Darrenbilly

    Darrenbilly TS Enthusiast Topic Starter Posts: 161

    Simulation

    I'm looking to use it for simulation games such as Sims 3. 18 wheels of steel. Bus drive. With my current GC they are terrible! AGC viachrome or something. It judders and freezes like heck.
     
  18. red1776

    red1776 Omnipotent Ruler of the Universe Posts: 5,219   +157

    whats your current GC?
     
  19. captaincranky

    captaincranky TechSpot Addict Posts: 11,672   +1,871

    I'm pretty sure you still have it all wrong. A Prescott P4 draws about 90watts itself.

    In any event, I think a laptop almost uses that much power.

    To the other extreme there certainly aren't very many, single video card rigs, that really need an >>honest<< 700 watt PSU.

    As red pointed out, although much less vigorously than I plan to, a 9400GT video card is a slug, period! It might be useful to drive HTPC video, not much more.

    You entry point for reasonably good gaming should be at least a 9600GT. There may be some 8800GT cards still around, and available at close to the same price. One of these might be a nice choice.

    I'll leave it to others more knowledgeable than myself to debate the virtues and vices of ATI vs ATI or ATI vs Nvidia. I simply don't care that much, plus it's getting late

    I recommend a (good) 430 watt PSU for the 9600GT, and possibly a 500 watter for the 8800GT. The newer 9800GT might actually need a touch less power than the 8800 series cards
     
  20. SNGX1275

    SNGX1275 TS Forces Special Posts: 10,704   +397

    I believe his 151. The high end MacBook Pros (even the 17") use an 85W power adapter, and people can use the computer with that plugged in without draining the battery, so that shows they are using 85W or less. I suspect most laptops draw much less than that. My old Powerbook 15" uses something like 30W.

    As for the vid cards, I have the old 8800GTS 320 and my entire system uses 244W with gaming in Bioshock (all the graphics settings maxed on a 1680x1050 monitor). I suspect the 8800GT cards use less power than my 320 because they are a smaller nm design (and its single bay, so it creates less heat, so probably less power consumption). So a solid 400W PSU would be fine. You could go less, but it may be getting hard to find good manufacturers selling PSUs with that low of wattage now.
     
  21. captaincranky

    captaincranky TechSpot Addict Posts: 11,672   +1,871

    Oddly, for my current system (E7300, Gigabyte P45, 9500GT), Antec's PSU calculator suggests about 330 Watts. This is with the Atec PSU calculator. I'm sure there is a whole lot of back story there, but that's not my point.

    Our OP's "system spec" button fails to "boot", or "load" if you prefer. So, that sort of renders this topic theoretical, or perhaps philosophical, at least with respect to his current system. Here again, your choice.

    I will go on record as "staying the course" with my original assessment that almost nobody needs a PSU capable of delivering 700 >>honest<< watts :wave:

    As an afterthought, I'm also sure that his choice of new case doesn't add to the PSU requirements....:rolleyes: Was the "rolleyes" enough, or should I also say, "just joking"?

    Adden-dumb: I just plugged in the OPs dream system into the Antec PSU calculator, I came up with 295 watts. does that seem reasonable? Since our OP DIDN'T include a HDD, I put in 1 of each, IDE and SATA. So sue me for the 15 watt error.
     
  22. SNGX1275

    SNGX1275 TS Forces Special Posts: 10,704   +397

    My #s came from a kill-a-watt device.
     
  23. captaincranky

    captaincranky TechSpot Addict Posts: 11,672   +1,871

  24. SNGX1275

    SNGX1275 TS Forces Special Posts: 10,704   +397

    For our purposes here they provide identical functionality. The resolution on the $890 beast is to .1 watts where as mine only does whole numbers... Theirs will also do DC, which is completely useless in their tests and in our discussion, so.. looks to me like they wasted about $860.
     
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