If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Gtx 580 stock
Is a 700 watt power supply strong enough to run a gtx 580 ? i have an ocz modxstream 700 watt power supply |
#2
|
|||
|
|||
Gtx 580 stock
PcGAmeR22 wrote:
Is a 700 watt power supply strong enough to run a gtx 580 ? i have an ocz modxstream 700 watt power supply http://www.xbitlabs.com/articles/gra...0_5.html#sect0 GTX 580 264.1 watts 12V slot power = 3 amps 12V 2x3 plug = 6.2 amps 12V 2x4 plug = 12.7 amps Slot power may come from a different current-limited 12V rail than the other two. You need to work out the power drain of your other computer components, to know whether the 700W is enough. My guess is, it's fine. But if you have something strange we don't know about (like a pump for water cooling, or a TEC for the CPU), then anything is possible. Paul |
#3
|
|||
|
|||
Gtx 580 stock
Thu, 05 Jan 2012 16:58:27 -0500, Paul wrote:
PcGAmeR22 wrote: Is a 700 watt power supply strong enough to run a gtx 580 ? i have an ocz modxstream 700 watt power supply http://www.xbitlabs.com/articles/gra...0_5.html#sect0 GTX 580 264.1 watts 12V slot power = 3 amps 12V 2x3 plug = 6.2 amps 12V 2x4 plug = 12.7 amps Slot power may come from a different current-limited 12V rail than the other two. You need to work out the power drain of your other computer components, to know whether the 700W is enough. My guess is, it's fine. But if you have something strange we don't know about (like a pump for water cooling, or a TEC for the CPU), then anything is possible. Paul +1 Bill |
#4
|
|||
|
|||
Gtx 580 stock
This is my rig intel dual core e7500 2.93 ghz 3 gigs of ddr3 ram 1 cooling fan , a cpu fan of course and its heatsink |
#5
|
|||
|
|||
Gtx 580 stock
PcGAmeR22 wrote:
This is my rig intel dual core e7500 2.93 ghz 3 gigs of ddr3 ram 1 cooling fan , a cpu fan of course and its heatsink http://www.xbitlabs.com/articles/gra...0_5.html#sect0 GTX 580 264.1 watts 12V slot power = 3 amps 12V 2x3 plug = 6.2 amps 12V 2x4 plug = 12.7 amps With the Modstream, those loads are likely on the same rail. E7500 65W (times 1/0.90 for Vcore efficiency) = 72W or 12V @ 6A Cooling fans 12V @ 0.5A allocated or 6W Hard drive 12W (12V @ 0.6A, 5V @ 1A) --- some drives now are much less Optical drive 25W (12V @ 1.5A, 5V @ 1.5A) --- measured 12V @ 1A on a drive here with media in the tray Motherboard plus RAM allocation 50W (could come from 3.3V and/or 5V rails) USB power from +5VSB, allocate 10W more Total = 264.1+72+6+12+25+50+19= 448.1W (worst case, actual *will* be less) On a good day, unlikely to pass ~400W. Total power looks OK. ******* Now, to check current flow. Total 12V rail current must be allocated to the various rails on the supply. If the supply had one big 12V rail, you'd total all the currents (3+6.2+12.7)+6+0.5+0.6+1.5= 30.5 amps If the supply has 12V1 and 12V2, the CPU is on 12V2, the rest on 12V1. 12V1 = (3+6.2+12.7)+ 0.5+0.6+1.5= 24.5 amps 12V2 = 6 = 6.0 amps This is a picture of the label on the power supply. 25A limit on 12V1. http://images17.newegg.com/is/image/newegg/17-341-018-Z05?$S640W$ That means the 12V1 is getting close to the current limiter value of 25 amps. With no CD in the optical drive tray, the optical drive draws no 12V current (as that is a motor current). So without CD it is 23 amps. And that's only if the video card can be driven to the same state as in Xbitlabs review. So that's the only concern. The overall power rating is sufficient, but the asymmetric load on 12V is a bit of a concern. If the current limiter triggers on 12V1, the power supply will shut off and you'll have your answer (need new supply). If it stays running, the ~400W actual load should not be a problem thermally. Sometimes the supply shuts down, because a common heatsink in the supply is getting too hot. Paul |
#6
|
|||
|
|||
Gtx 580 stock
thank you for the information what can i do other than buying a new psu to run that card |
#7
|
|||
|
|||
Gtx 580 stock
PcGAmeR22 wrote:
thank you for the information what can i do other than buying a new psu to run that card That's a good question. On the surface of it, not much. You're stuck with the limitation. ******* Your first hint the supply isn't enough, is when there aren't enough PCI Express connectors on the power supply, to properly power the video card. That's your first hint the supply isn't right for the job. If the supply has one PCIe connector and you need two, chances are the output isn't big enough. Some supplies have a "massive single output". This does two things for you. On the positive side, you get to use all the current rating of the supply. For example, if the supply could make 12V @ 50A and your load is 30A, then there is no problem. +-----+ | | +---- 12V1 | 12V | | | @ |----- 50A limit -----+ | 50A | | | | +---- 12V2 +-----+ There is at least one industry standard, that stated that no more than X watts should be allowed on a single output of the supply. The claim is, that is a safety/fire thing. If that 50A output is shorted or partially shorted, things could get rather warm. To stop that, some supplies place a current monitor on each output section. In your case, two shunts are placed in the structure for monitoring. If either shunt detects more than 25 amps, the supply can shut off. The trip point may not be that precise - the thing is, to meet the rating, they don't want it to shut off at exactly 25 amps. It might trip at around 30% more than that. 25 * 1.3 = 32 amps for example. +-----+ | | +-- 25A limit -- 12V1 This could | 12V | | (monitor be your | @ |----- 50A limit -----+ OCP) design... | 50A | (indirect | | | thermal +-- 25A limit -- 12V2 +-----+ limit) (monitor OCP Another way to achieve the requirement of the standard, is to use separate transformer and diode rectifier structures for 12V1 and 12V2. But that is a less common solution. In that case, the rating on the supply label is "real" rather than contrived. I couldn't find a review of your exact supply model, so I don't know whether for sure it uses a single 50A circuit with limiters, or uses two 25A separate outputs. The separate output idea has mostly gone out of style. When they do this, the chassis of the power supply is a bit longer. +-----+ | | | 12V | | @ |----- 25A limit ----- 12V1 | 25A | | | +-----+ +-----+ | | | 12V | | @ |----- 25A limit ----- 12V2 | 25A | | | +-----+ So for some reason, a number of brands of supply where the single massive output is not current limited per output, they give you all the power you paid for. If current limiters are present, it's harder to draw that limit. For example, 25A for the processor side (12V2) is a very generous rating, when processors don't draw that much. It would take a server motherboard, with two sockets and two older generation Prescott-like processors, to draw that much current. If they'd made the limit a bit more asymmetric to begin with (like 30A, 20A) that might have made a bit more sense. And in any case, even when a supply has the label rating to meet the job, there is no guarantee it actually works as stated. With some of the cheaper brands, they take a 350W supply and put a 500W label on it. And you figure that out, when the supply "flakes out" on you and either the game exists abnormally (crashes) or the supply switches off on overheat. I'd say, give it a try. In terms of power rating, the supply seems to have a good power rating for the job. Two things could happen here. The supply might not really be rated for 50A, and the 12V output could be "soft". In which case, you might hear the hard drive spin up, spin down, over and over again. That's a hint the voltage is weak. (You can check that with a multimeter for example.) But if the current limiter of 25A on 12V1 is triggered by your 23A+ load, then you'll have your answer instantly. It's possible to mod the power supply, but I'm not even going to tell you how, for safety reasons. To make the mod, you have to be *absolutely* sure of the internal architecture (whether single transformer or multiple transformer type). It's better to just buy another one, than to explain to your fire insurance, what the hell you were doing :-) Paul |
#8
|
|||
|
|||
Gtx 580 stock
Thanks, Paul. Love the thoroughness and clarity of your response. Now if
we could only get the tech support folks to provide that service. I'll bet you Don't work tech support...... ;) T2 "Paul" wrote in message ... PcGAmeR22 wrote: thank you for the information what can i do other than buying a new psu to run that card That's a good question. On the surface of it, not much. You're stuck with the limitation. ******* Your first hint the supply isn't enough, is when there aren't enough PCI Express connectors on the power supply, to properly power the video card. That's your first hint the supply isn't right for the job. If the supply has one PCIe connector and you need two, chances are the output isn't big enough. Some supplies have a "massive single output". This does two things for you. On the positive side, you get to use all the current rating of the supply. For example, if the supply could make 12V @ 50A and your load is 30A, then there is no problem. +-----+ | | +---- 12V1 | 12V | | | @ |----- 50A limit -----+ | 50A | | | | +---- 12V2 +-----+ There is at least one industry standard, that stated that no more than X watts should be allowed on a single output of the supply. The claim is, that is a safety/fire thing. If that 50A output is shorted or partially shorted, things could get rather warm. To stop that, some supplies place a current monitor on each output section. In your case, two shunts are placed in the structure for monitoring. If either shunt detects more than 25 amps, the supply can shut off. The trip point may not be that precise - the thing is, to meet the rating, they don't want it to shut off at exactly 25 amps. It might trip at around 30% more than that. 25 * 1.3 = 32 amps for example. +-----+ | | +-- 25A limit -- 12V1 This could | 12V | | (monitor be your | @ |----- 50A limit -----+ OCP) design... | 50A | (indirect | | | thermal +-- 25A limit -- 12V2 +-----+ limit) (monitor OCP Another way to achieve the requirement of the standard, is to use separate transformer and diode rectifier structures for 12V1 and 12V2. But that is a less common solution. In that case, the rating on the supply label is "real" rather than contrived. I couldn't find a review of your exact supply model, so I don't know whether for sure it uses a single 50A circuit with limiters, or uses two 25A separate outputs. The separate output idea has mostly gone out of style. When they do this, the chassis of the power supply is a bit longer. +-----+ | | | 12V | | @ |----- 25A limit ----- 12V1 | 25A | | | +-----+ +-----+ | | | 12V | | @ |----- 25A limit ----- 12V2 | 25A | | | +-----+ So for some reason, a number of brands of supply where the single massive output is not current limited per output, they give you all the power you paid for. If current limiters are present, it's harder to draw that limit. For example, 25A for the processor side (12V2) is a very generous rating, when processors don't draw that much. It would take a server motherboard, with two sockets and two older generation Prescott-like processors, to draw that much current. If they'd made the limit a bit more asymmetric to begin with (like 30A, 20A) that might have made a bit more sense. And in any case, even when a supply has the label rating to meet the job, there is no guarantee it actually works as stated. With some of the cheaper brands, they take a 350W supply and put a 500W label on it. And you figure that out, when the supply "flakes out" on you and either the game exists abnormally (crashes) or the supply switches off on overheat. I'd say, give it a try. In terms of power rating, the supply seems to have a good power rating for the job. Two things could happen here. The supply might not really be rated for 50A, and the 12V output could be "soft". In which case, you might hear the hard drive spin up, spin down, over and over again. That's a hint the voltage is weak. (You can check that with a multimeter for example.) But if the current limiter of 25A on 12V1 is triggered by your 23A+ load, then you'll have your answer instantly. It's possible to mod the power supply, but I'm not even going to tell you how, for safety reasons. To make the mod, you have to be *absolutely* sure of the internal architecture (whether single transformer or multiple transformer type). It's better to just buy another one, than to explain to your fire insurance, what the hell you were doing :-) Paul |
#9
|
|||
|
|||
Gtx 580 stock
Tom wrote:
Thanks, Paul. Love the thoroughness and clarity of your response. Now if we could only get the tech support folks to provide that service. I'll bet you Don't work tech support...... ;) T2 I wish the info was on a website somewhere. I've only been piecing this together from info here and there. For example, at one time, I used to take the 12V1 and 12V2 thing verbatim, that when you saw that, it was two transformers and two separate circuits. Until I read somewhere, instead they were faking it with one transformer and two monitor circuits. There are a couple good power supply review sites, like jonnyguru, that have some of that kind of info. Some sites disassemble the supply, for a look at the design. There were only a few, truly independent output supplies. I remember a picture of one, with four transformers inside it, and the chassis was a bit longer than your average supply. While that might meet someone's idea of safety, it isn't very convenient for users. Supplies like that, you're highly likely to only use three of the four outputs. And end up paying for one of them, for nothing. The other issue with those kinds of supplies, is getting reliable info on which wires are connected to 12V3 and 12V4. Again, a supply review might be the only source of info (where the reviewer requested the info directly from the company). Paul |
#10
|
|||
|
|||
Gtx 580 stock
does the 580 require 2 pci wires i have 2 they came with my mod power supply |
|
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
RFI GTX 580 | Rick[_9_] | Homebuilt PC's | 0 | January 13th 11 05:09 PM |
GeForce GTX 260, GTX 280 (GT200) vs Radeon HD 4850, HD 4870 (RV770) | NV55 | Nvidia Videocards | 6 | June 7th 08 12:53 AM |
GeForce GTX 260, GTX 280 (GT200) vs Radeon HD 4850, HD 4870 (RV770) | NV55 | Ati Videocards | 6 | June 7th 08 12:53 AM |
Next-gen NVIDIA GeForce GTX 280, GTX 260 Specifications Unveiled | NV55 | Nvidia Videocards | 1 | May 21st 08 01:32 PM |
Next-gen NVIDIA GeForce GTX 280, GTX 260 Specifications Unveiled | NV55 | Ati Videocards | 1 | May 21st 08 01:32 PM |