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Will my psu be enough for a 7850?

KaraminalKaraminal BirminghamPosts: 58Member

I have a CiT 480W PSU and i hear the minimum reqs for a 7850 is a 500W psu. I dont want to fry all the components in my pc and an upgrade is affordable. ( I live in the UK). Also would a 600W be enough?

 

My build is:

amd fx 6300

CIT 480W psu

8GB DDR3 1600Mhz RAM

A 970 chip motherboard (AMD)

1TB HDD

Comments

  • shadeviceshadevice memphis, TNPosts: 68Member

    Why chance it dude? the PSU supplys power to all hardware your computer uses. If you're using one lower than a video card recommends then your comp will be stressed for power or not run optimal.

    Get a 800w or better and rest easy. 

  • SavageHorizonSavageHorizon ParisPosts: 2,076Member Uncommon
    Why would you get a PSU that is actually less than the recommended spec? 

    Coolermaster Cosmos II Case
    Corsair AX1200W Modular PSU
    Intel Core i7 3970X OC 4.50GHz
    Asus P9X79 PRO Intel X7
    16GB (4x4GB) DDR3 PC3-1866MHz
    840 Series 250GB SSDs
    Seagate Barracuda 2TB HDDs
    EVGA SuperClocked GTX TITAN 6GB GDDR5 SLi

  • syntax42syntax42 Columbus, OHPosts: 1,305Member Uncommon
    Originally posted by SavageHorizon
    Why would you get a PSU that is actually less than the recommended spec? 

    Recommended specs for the power supply make assumptions which they should not be making based on the video card alone.  The rest of your system frequently has a greater impact on the power draw than the video card.  Trusting their suggestion is like trusting the recommended specs for video game system requirements.

     

    There are a lot of technical details about power supplies, power draw, and how they calculate all of it.  I'll skip those details and just make a suggestion based on the system posted above:  Try it.  The chance of damaging things with undervoltage is slim to none.  If the parts you listed are all you have running in your case, you might be fine.  If the system seems unstable, has odd crashes, or gets blue screens, upgrade to a decent 600W power supply.

  • RidelynnRidelynn Fresno, CAPosts: 4,178Member Uncommon


    Originally posted by syntax42
    Originally posted by SavageHorizon Why would you get a PSU that is actually less than the recommended spec? 
    Recommended specs for the power supply make assumptions which they should not be making based on the video card alone.  The rest of your system frequently has a greater impact on the power draw than the video card.  Trusting their suggestion is like trusting the recommended specs for video game system requirements.


    There are a lot of technical details about power supplies, power draw, and how they calculate all of it.  I'll skip those details and just make a suggestion based on the system posted above:  Try it.  The chance of damaging things with undervoltage is slim to none.  If the parts you listed are all you have running in your case, you might be fine.  If the system seems unstable, has odd crashes, or gets blue screens, upgrade to a decent 600W power supply.


    There are good reasons not to try it: If a power supply is overloaded and doesn't have sufficient undervoltage protection - and most cheap power supplies do ~not~ have sufficient protection, it ~can~ damage hardware. Memory, video cards, and motherboards are very commonly permanently harmed by faulted or overloaded power supplies.

    In a gaming computer, the video card commonly is the single biggest draw on the system, and in high end cards, more than the entire rest of the system combined.

    Going with just higher published watts isn't the answer either. Power supply watts is a marketing number, and video card manufacturers do somewhat fluff that number, especially since not all power supplies are created equal - many "480W" power supplies may really only be 285W units, and completely melt down if you try to draw 350W - those numbers aren't just made up, there are many units that have done just that.

    Corsair PSU ad - now that is an ad for Corsair power supplies, but the units they are testing are real, off the shelf units, and they are dying way before their rated "watts". There are many, many evaluations and reviews of power supplies aside from advertisements which tell the same story, this video is just a nice way of seeing it.

    A 7850 has a TDP of 130W give or take. CPU's are mostly all around 100W. ~Everything else~ in your system is around 100W (motherboard, hard drives, fans, etc), with some extra fluff to allow for miscellaneous hardware.

    So all in all, that system may use a real 330W of power under full load, and most commonly probably under 100W. That being said, I don't know that I would necessarily trust a generic "480W" unit to power that. A ~good~ 450W unit I would have no trouble saying go ahead and try it.

    The problem is, it's hard to tell a good unit from a bad. It takes a lot of expensive equipment and some EE training in order to properly review a power supply - you can't just open up the box, pop it in a computer, and report that no smoke came out for a good review. I like HardOCP reviews - they do some of the most brutal testing, and if a unit passes their test, it's a good unit. They aren't the only good place to see reviews, and they don't review every unit out there, but they are one of the few that I would look at.

  • SavageHorizonSavageHorizon ParisPosts: 2,076Member Uncommon
    Originally posted by syntax42
    Originally posted by SavageHorizon
    Why would you get a PSU that is actually less than the recommended spec? 

    Recommended specs for the power supply make assumptions which they should not be making based on the video card alone.  The rest of your system frequently has a greater impact on the power draw than the video card.  Trusting their suggestion is like trusting the recommended specs for video game system requirements.

     

    There are a lot of technical details about power supplies, power draw, and how they calculate all of it.  I'll skip those details and just make a suggestion based on the system posted above:  Try it.  The chance of damaging things with undervoltage is slim to none.  If the parts you listed are all you have running in your case, you might be fine.  If the system seems unstable, has odd crashes, or gets blue screens, upgrade to a decent 600W power supply.

    I don't build them i just pay the money for pre build so i wouldn't know i guess. I know mine is 1200W but that came with the system.

     

    Coolermaster Cosmos II Case
    Corsair AX1200W Modular PSU
    Intel Core i7 3970X OC 4.50GHz
    Asus P9X79 PRO Intel X7
    16GB (4x4GB) DDR3 PC3-1866MHz
    840 Series 250GB SSDs
    Seagate Barracuda 2TB HDDs
    EVGA SuperClocked GTX TITAN 6GB GDDR5 SLi

  • Lazarus71Lazarus71 Celina, OHPosts: 1,025Member Uncommon
    I have been running a 7850 2gb on my system for months now with a stock 480w that came in my PC and never had a problem. However I would say if you have the cash why not get a better PSU just to be safe. I will say though that I am impressed with how little power this card draws compared to other cards I have had in the past.

    No signature, I don't have a pen

  • SavageHorizonSavageHorizon ParisPosts: 2,076Member Uncommon
    Originally posted by Karaminal

    I have a CiT 480W PSU and i hear the minimum reqs for a 7850 is a 500W psu. I dont want to fry all the components in my pc and an upgrade is affordable. ( I live in the UK). Also would a 600W be enough?

     

    My build is:

    amd fx 6300

    CIT 480W psu

    8GB DDR3 1600Mhz RAM

    A 970 chip motherboard (AMD)

    1TB HDD

    If you are not sure then go here, i bought my system from these people and was shipped out to france.

    You live in the UK so posting will be cheap. 

    http://www.overclockers.co.uk/productlist.php?groupid=701&catid=123&subid=2463

    http://forums.overclockers.co.uk/

     

    Coolermaster Cosmos II Case
    Corsair AX1200W Modular PSU
    Intel Core i7 3970X OC 4.50GHz
    Asus P9X79 PRO Intel X7
    16GB (4x4GB) DDR3 PC3-1866MHz
    840 Series 250GB SSDs
    Seagate Barracuda 2TB HDDs
    EVGA SuperClocked GTX TITAN 6GB GDDR5 SLi

  • ReizlaReizla AlkmaarPosts: 3,300Member Uncommon
    Originally posted by Lazarus71
    I have been running a 7850 2gb on my system for months now with a stock 480w that came in my PC and never had a problem. However I would say if you have the cash why not get a better PSU just to be safe. I will say though that I am impressed with how little power this card draws compared to other cards I have had in the past.

    Stock PSU's are mostly sub-par ones, not delivering the required amount of power required. My advice is either not to stress the GPU to the max (then it'll need the 500W) or upgrade the PSU to the minimum 500W they advice (600W would be better IMO).

    For my GTX460 SLI system, I made calculations of my whole system and came out on a ~550W power requirement. With a 620W PSU I would theoretically be able to run the SLI, but if I'd stress both GPUs and my CPU, the PSU would be running on max (remember that the Wattage labeled on the PSU is on 100% usage and only be used once in a while as PEAK sonsumption - regular testing is on 80% of max PSU power). For this reason I upgraded to a 750W PSU and it all runs fine.

    @OP Best get the 600W PSU or even the 700W...

    AsRock 990FX Extreme3
    AMD Phenom II 1090T ~3.2Ghz
    GEiL 16Gb DDR3 1600Mhz
    ASUS GTX970 3x HD monitor 1920x1080

  • Lazarus71Lazarus71 Celina, OHPosts: 1,025Member Uncommon
    Originally posted by Reizla
    Originally posted by Lazarus71
    I have been running a 7850 2gb on my system for months now with a stock 480w that came in my PC and never had a problem. However I would say if you have the cash why not get a better PSU just to be safe. I will say though that I am impressed with how little power this card draws compared to other cards I have had in the past.

    Stock PSU's are mostly sub-par ones, not delivering the required amount of power required. My advice is either not to stress the GPU to the max (then it'll need the 500W) or upgrade the PSU to the minimum 500W they advice (600W would be better IMO).

    For my GTX460 SLI system, I made calculations of my whole system and came out on a ~550W power requirement. With a 620W PSU I would theoretically be able to run the SLI, but if I'd stress both GPUs and my CPU, the PSU would be running on max (remember that the Wattage labeled on the PSU is on 100% usage and only be used once in a while as PEAK sonsumption - regular testing is on 80% of max PSU power). For this reason I upgraded to a 750W PSU and it all runs fine.

    @OP Best get the 600W PSU or even the 700W...

    Which is why I said if he has the cash why not get a better PSU to be safe :) He definately does not need a 600 or 700 watt psu though I would think a quality 500w 550W PSU would be fine.

    No signature, I don't have a pen

  • AmjocoAmjoco Layton, UTPosts: 4,779Member Uncommon
    I always go overkill on PSUs for any of them I build. Here is a calculator you can look at that may help you decide rather than listening to mmo nerds.

    Death is nothing to us, since when we are, Death has not come, and when death has come, we are not.

  • Lazarus71Lazarus71 Celina, OHPosts: 1,025Member Uncommon
    Originally posted by Amjoco
    I always go overkill on PSUs for any of them I build. Here is a calculator you can look at that may help you decide rather than listening to mmo nerds.

    I'm sure Quizzical will be in here with his expert opinion soon, that's who I would listen to :)

    No signature, I don't have a pen

  • AmjocoAmjoco Layton, UTPosts: 4,779Member Uncommon
    Originally posted by Lazarus71
    Originally posted by Amjoco
    I always go overkill on PSUs for any of them I build. Here is a calculator you can look at that may help you decide rather than listening to mmo nerds.

    I'm sure Quizzical will be in here with his expert opinion soon, that's who I would listen to :)

    /nod

    Death is nothing to us, since when we are, Death has not come, and when death has come, we are not.

  • Aison2Aison2 MarburgPosts: 624Member

    Those 700w+ people are just uninformed. Im running similiar setup with 400w. Your system will draw not even 300w unless you manually increase voltage for overclocking  Load above 80% could be dangerous if you have a bad psu as they can show high error margins in voltage but you would never reach that load in your case.

     

    The reason you get recommendations of roughly double in magazines is that the psu works best arround 50% load. If you buy 700w+  like the people here recommended you will hardly reach 40% load which means less efficiency = more wasted energy=wasted money . This is even worse if you work alot on the system where both gpu&cpu sleep and draw only 50w, you could see here a difference of 10-20% less in efficiency if you buy a 800w compared to your current.

     

     

    Pi*1337/100 = 42

  • QuizzicalQuizzical Posts: 14,783Member Uncommon

    That power supply is worthless garbage.  It would not be a good value for the money even if it were completely free.  Hopefully you haven't bought it yet, or bought it recently enough that you can still return it.  Regardless, you should replace it at once, regardless of the rest of the hardware in your system.

    Here's a link, so that everyone else can see the specs:

    http://www.scan.co.uk/products/480w-cit-black-edition-120mm-quiet-fan-atx-v22-psu

    The price tag should pretty much give the game away.  It's £15 before tax.  I don't think I've ever seen a decent quality power supply for less than $35 before rebates.  Ever.  Of any wattage.

    It doesn't have an 8-pin CPU power connector, as has been the standard for a long time.  It doesn't have a 6-pin PCI-E power connector, which means that whoever built it doesn't think it can handle a video card over 75 W.  It may or may not have enough molex power connectors to plug in all of your case fans.  It may or may not have enough SATA power connectors to plug everything in, either, as it only has two, while needing three is pretty common (1 for an SSD, 1 for a hard drive, 1 for an optical drive).  It does, however, have a floppy drive connector, which even some modern high end power supplies lack, which should tell you something about the age of the design.

    Moving on, modern computers draw most of their power on the +12 V rails, with only a little bit on other rails.  The CPU and GPU chips use the +12 V rail exclusively, and those are the two big power consumers.  That power supply has two +12 V rails, one rated at 10 A and the other at 13 A.  The rated wattages on those are 10 A * 12 V = 120 W and 13 A * 12 V = 156 W.  If you pull over 276 W total on the +12 V rails, you're guaranteed to be running the power supply out of spec.  That would be a very, very, very bad idea, considering that it probably wouldn't be very hard to fry it while running everything in spec.

    Meanwhile, when a power supply has several +12 V rails, the total amount of wattage that they can deliver usually isn't additive.  For example, the power supply that I personally use (Enermax Pro 82+ 525 W) has three +12 V rails rated at 25 A each, but the three added together can only deliver 40 A in total, not 75 A.  How much can those two +12 V rails deliver simultaneously?  15 A?  20 A?  The power supply doesn't say.  If it could do 23 A, they'd tell you so.

    There's also the issue that even if a power supply has enough power, you have to get it on the right rails.  Each cable that can deliver +12 V power is attached to one rail or the other.  You don't get to pick which rail, and it can't pull some power from each.  If you were to use a 125 W CPU and have it plugged into the 10 A rail that is only rated as being able to deliver 120 W, then you're already running the power supply out of spec.

    While there is a case for having multiple +12 V rails on a higher wattage power supply (the reputable power supply vendors are split on whether one rail or several is a better idea), there is no case for having a +12 V rail rated at 10 A, or even 13 A.  I'd take a dim view of any +12 V rail rated below about 20 A.  I don't think I've ever seen a power supply with any +12 V rail rated below 15 A for which it wasn't immediately obvious that it was garbage.  (They could easily have existed long ago, before computers pulled so much power, but I didn't keep up with power supplies then.)

    And that's all assuming that they're honest with the listed specs.  There isn't any way to objectively test hardware and say that it has such and such specs.  Power supply vendors can label the specs as being whatever they want.  Reputable vendors label conservatively, as they have a reputation to protect and don't want to sully their reputation by having power supplies fry while running inside the rated specs.  Disreputable power supply vendors often use inflated numbers to try to convince clueless customers that it must be good because it has big numbers on it.

    Also, the power supply lacks 80 PLUS certification.  A consortium of electric utilities runs the 80 PLUS certification program to provide independent certification of power supplies.  Their standards aren't very high, and a number of power supplies that are downright mediocre or even an outright danger to your system pass certification.  But the low standards are meant to make it easy for power supplies to pass, and those that can't tend to be downright awful.  (I can only name two recent lines of power supplies off hand that I'd trust to power a nettop even though they couldn't get 80 PLUS certification:  the original Corsair CX series, and the lower wattage Antec Basiq models.  And both of those cost a lot more than £15.)

    The risk of a bad power supply isn't merely that you fry the power supply.  The risk is that as the power supply power supply dies, it might fry everything else in your system.  A £15 power supply that fries a £100 CPU and a £150 video card, among other things, was not a good value for the money.

    Rather than running a high risk of frying your system, how about getting a decent budget power supply that will actually work?

    http://www.scan.co.uk/products/450w-xfx-pro-core-edition-p1-450s-x2b9-85-eff-80-plus-bronze-sli-crossfire-eps-12v-fan-atx-v231-psu

    It only has three Molex connectors, which means that you can only plug in 3 case fans.  But 34 A (= 408 W) on the +12 V rail is plenty of power for a modern gaming rig running a Radeon HD 7850.  And the power supply is built by Seasonic, so it's highly probable that it can do what it says it can do.

  • AmjocoAmjoco Layton, UTPosts: 4,779Member Uncommon

    Quizzical scares me a little bit. The OP got the NASA answer from him.

    Death is nothing to us, since when we are, Death has not come, and when death has come, we are not.

  • lifeordinarylifeordinary AgadirPosts: 646Member
    Official specification on ATI website rcommend 500W or above for your card and 600 W and above for crossfire. As long as it is branded and recommended PSU (there is a list of recommended brands on ATI website) you are good to go with 550 W.
  • KaraminalKaraminal BirminghamPosts: 58Member
  • jdnewelljdnewell Spring Hill, TNPosts: 2,150Member Uncommon
    Originally posted by Karaminal

    Would this one be slightly better than?

     

    http://www.ebay.co.uk/itm/151005499880?ssPageName=STRK:MEBIDX:IT&_trksid=p3984.m1431.l2649

    It may be a little better, but not enough to justify the purchase. That guys is selling it for cheap on ebay for a reason lol.

    If your going to buy a new PSU go ahead and spend the money on a decent one. Better to get a decent PSU now that risk a cheapo one damaging your entire system just so you could save 20bucks

    I personally have seasonic Gold rated PSUs in both my computers. If I havent learned but one thing from Quizzical its buy a decent power supply.

  • AethaerynAethaeryn Kitchener, ONPosts: 1,973Member Uncommon
    Originally posted by Amjoco

    Quizzical scares me a little bit. The OP got the NASA answer from him.

    I always do my homework (the best I can) before and after his suggestions and so far have gotten what he has suggested.  I love the NASA answers  because I generally know about 75% of what he is talking about which I think is pretty good for someone who has been out of the loop.  The more info the better :)

    Wa min God! Se æx on min heafod is!

  • QuizzicalQuizzical Posts: 14,783Member Uncommon
    Originally posted by Karaminal

    Would this one be slightly better than?

     

    http://www.ebay.co.uk/itm/151005499880?ssPageName=STRK:MEBIDX:IT&_trksid=p3984.m1431.l2649

    Better than the one you linked before?  Probably.  Good enough to justify buying it?  Not really, as I have no idea how good it is.  Moving from "will probably fry things" to "may or may not fry things" is progress of sorts, but the latter isn't where you want to stop.  If you're buying something used, there's also the risk that the previous owner has good reasons to want to be rid of it.  It's not that expensive to get a known good power supply like the one I linked earlier.

    If you can't fit both a Radeon HD 7850 and a decent power supply into your budget, then get a cheaper video card.  A Radeon HD 7770 or GeForce GTX 650 Ti is probably cheaper than a 7850 by enough to make room for a good power supply.

  • syntax42syntax42 Columbus, OHPosts: 1,305Member Uncommon

    Wow.  I should have looked up the specs on it.  The thing is worth less than the copper they put into it.

     

    No PCIe power connector?  I can't even remember the last time I saw a power supply without one of those.  I would be wary of running any video card off the motherboard with the power load they require now.  I know the rating on PCIe says it should be able to handle a video card, but it isn't worth risking frying the motherboard.

  • QuizzicalQuizzical Posts: 14,783Member Uncommon
    Originally posted by syntax42

    Wow.  I should have looked up the specs on it.  The thing is worth less than the copper they put into it.

     

    No PCIe power connector?  I can't even remember the last time I saw a power supply without one of those.  I would be wary of running any video card off the motherboard with the power load they require now.  I know the rating on PCIe says it should be able to handle a video card, but it isn't worth risking frying the motherboard.

    It really depends on the intended purpose.  For example, this doesn't have a PCI-E power connector:

    http://www.newegg.com/Product/Product.aspx?Item=N82E16817151113

    And it's a high quality product, too.  But it's not meant to power a beefy gaming system.  It's meant for very small form factor computers where a standard ATX power supply won't physically fit.  In a small enough form factor, you can't dissipate a ton of heat from a video card anyway, so it doesn't need to power a high-power gaming card.  It doesn't need 8 SATA connectors because it's meant for a tiny case where you can't fit very many things.  Stick it in a system that never pulls 150 W even under heavy loads and 300 W with the few connectors it has will be plenty.

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