td (OP)
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May 13, 2011, 10:11:33 PM |
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How big of a power supply do I need for two 5870's? I see a lot of recommendations and people using 900 watt + for 5970's and such. Will these smaller requirements need that much power?
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keybaud
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May 13, 2011, 10:24:56 PM |
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I'm running 3 5870s off a 700 W PSU with an Intel E6400. At the wall I'm drawing 670 Watts, so I'm close to the limit, if not over it. I was drawing 280 Watts with one 5870, so each card is approx 185 Watts. I'm using a Coolermaster 700W Silent Pro, which is 80+ Gold certified and only cost £79 inc P&P in the UK.
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Sukrim
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May 13, 2011, 10:28:55 PM |
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Depending on the rest of your hardware you can expect that 2 5870 GPUs will draw ~200W each under load.
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mewantsbitcoins
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May 13, 2011, 10:33:50 PM |
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I'm running 3 5870s off a 700 W PSU with an Intel E6400. At the wall I'm drawing 670 Watts, so I'm close to the limit, if not over it. I was drawing 280 Watts with one 5870, so each card is approx 185 Watts. I'm using a Coolermaster 700W Silent Pro, which is 80+ Gold certified and only cost £79 inc P&P in the UK.
keybaud may I ask what motherboard you are using? |
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keybaud
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May 13, 2011, 11:40:25 PM |
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Intel D975XBX. I got it off Ebay a week or so ago with the E6400, 2GB DDR 2 and a 320 GB HDD for the grand total of £55.
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mewantsbitcoins
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May 13, 2011, 11:41:47 PM |
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Thanks. I am looking for something that has the capacity for 3 cards
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compro01
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May 14, 2011, 02:31:30 AM |
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I'm running 3 5870s off a 700 W PSU with an Intel E6400. At the wall I'm drawing 670 Watts, so I'm close to the limit, if not over it. I was drawing 280 Watts with one 5870, so each card is approx 185 Watts. I'm using a Coolermaster 700W Silent Pro, which is 80+ Gold certified and only cost £79 inc P&P in the UK.
You've got a fair bit of headroom left. 670W wall at 87% efficiency is 582W of output, so you've got 118W of extra headroom, assuming your temps are in spec. |
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ElectroGeek007
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May 14, 2011, 05:48:31 AM |
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I am also using the Intel D975XBX also; with an Intel E6300, 2GB DDR2 667, a reference 5850, and a non-reference Sapphire 5870, and this PS is serving me well (I don't have any exact usage figures, though): http://www.newegg.com/Product/Product.aspx?Item=N82E16817371026&cm_re=earthwatts-_-17-371-026-_-Product |
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bytemaster
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May 15, 2011, 02:17:12 PM |
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I think I just blew a 1200W power supply powering 2x Nvidia 295's just 18 hours after I started GPU mining. (At least I hope that is all I blew).
It tripped the circuit breaker.
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1bitc0inplz
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May 15, 2011, 02:47:09 PM |
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What does reference and non-reference mean in this context? And how does that effect wattage? |
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Orcworm
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May 15, 2011, 02:52:17 PM |
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I think I just blew a 1200W power supply powering 2x Nvidia 295's just 18 hours after I started GPU mining. (At least I hope that is all I blew).
It tripped the circuit breaker.
What model PSU is it? What does reference and non-reference mean in this context? And how does that effect wattage? A reference GPU uses the 'stock' ATI / Nvidia board and heatsink, non-reference cards typically use boards that may restrict overclocking (By locking the voltage, for example) or they may have a custom cooler fitted. |
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bytemaster
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May 15, 2011, 02:57:56 PM |
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I think I just blew a 1200W power supply powering 2x Nvidia 295's just 18 hours after I started GPU mining. (At least I hope that is all I blew).
It tripped the circuit breaker.
What model PSU is it? Thermaltake W0133RU ToughPower 1200W Modular Power Supply |
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bytemaster
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May 15, 2011, 03:05:02 PM |
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Assuming the power supplies are only 80% efficient, a 1200W supply is can really only provide 960W.
Operating a power supply for extended periods of time near the upper end of its rated range is sure to find the weakest component.
So I would recommend sizing your power supply 30-50% more than it is actually using to prevent it from overheating or failing early.
In my case, I decided to replace it with the ToughPower 1350W supply, it was cheaper and has 10% more margin for error.
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Dyaheon
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May 15, 2011, 03:54:20 PM |
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Assuming the power supplies are only 80% efficient, a 1200W supply is can really only provide 960W.
No, what that means it can supply 1200W. Thus drawing 1500W from wall at 80% efficiency. Leaving some headroom is of course recommended. PSUs tend to get noisy at high loads, and tend to be most efficient around 50% load. So it's probably a good idea to leave some 20-30% headroom at least. |
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SgtSpike
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May 16, 2011, 02:54:12 AM |
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On a related note, would a 650w PSU be necessary for running 3x5850's, or could I drop it down to a decent 550w or 500w? Recommendations? The other components would just be a 65TDP C2D, single stick of memory, and HDD/fans. Well, and the motherboard, obviously.
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aistto
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May 16, 2011, 03:46:16 AM |
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On a related note, would a 650w PSU be necessary for running 3x5850's, or could I drop it down to a decent 550w or 500w? Recommendations? The other components would just be a 65TDP C2D, single stick of memory, and HDD/fans. Well, and the motherboard, obviously.
if you going to OC your cards choose 650w PSU |
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SgtSpike
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May 16, 2011, 03:46:47 AM |
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On a related note, would a 650w PSU be necessary for running 3x5850's, or could I drop it down to a decent 550w or 500w? Recommendations? The other components would just be a 65TDP C2D, single stick of memory, and HDD/fans. Well, and the motherboard, obviously.
if ypu going to OC your cards choose 650w PSU Yeah, good point. I do plan to overclock them. |
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aistto
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May 16, 2011, 03:52:09 AM |
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On a related note, would a 650w PSU be necessary for running 3x5850's, or could I drop it down to a decent 550w or 500w? Recommendations? The other components would just be a 65TDP C2D, single stick of memory, and HDD/fans. Well, and the motherboard, obviously.
if ypu going to OC your cards choose 650w PSU Yeah, good point. I do plan to overclock them. btw, if you going to use 5870 bios your card will consume more than 150w. I think it about 160 - 170 w. |
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