4x 5850 Setup, Minimum PSU needed? - page 3.

afro25

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Quote from: krzynek1 on July 18, 2011, 09:32:28 AM

my rig with 4x5830 sapphires with clocks 1000/300 have power consumption = 786 W

other with 4x5850 OC = 640 W

this is power consumption "from wall"

What are you overlocking the 5850's to? It seems i should be able to get my 4th card working in this rig if i get a similar power usage to you

krzynek1

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my rig with 4x5830 sapphires with clocks 1000/300 have power consumption = 786 W

other with 4x5850 OC = 640 W

this is power consumption "from wall"

afro25

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Quote from: m3sSh3aD on July 18, 2011, 09:12:02 AM

I fried a 850 bogo psu with 3 cards. Didnt even do 2

Wow so your 850w psu wouldn't cover 3 cards? Which cards were you trying it with?

I've just got a power reading for my rig, it's using 540-560w at the moment, that's the 3 5850's (840 core, 150 mem) a phenom 2 x4 and 8gb ram...

I've heard that 5850's can run at 150w, if so then i might be able to get away with sticking that in my machine right?

I can try downclocking the processor to see if that frees up any space.

m3sSh3aD

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A decent 1KW is plenty i say. I got 4 cards up on a decent 750 for 2x plus the system and a 650w bogo powering the other 2 cards. Wither way you look at it, its £150, least in the uk

I fried a 850 bogo psu with 3 cards. Didnt even do 2

afro25

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One more thing i need to ask;

I've just had some PCIE x4 to x16 riser cards arrive, if i tried to put my 4th card in my setup and there wasn't enough power, would it be safe? Would the pc simply not turn on / turn itself off, or would anything blow up?

afro25

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Quote from: sven on July 17, 2011, 10:33:52 PM

i have 3x5850 and 1x5870 running on a corsair 800w psu
all overclocked with default voltages

I'm sure i've read that the 5850's are the most power efficient in the 58XX group, would you know how much extra power your 5870 takes over the 5850's?

I forgot to mention one thing, i'm currently overclocking the core of each card to 840MHz and underclocking the memory to 150MHz (I know everyone says 300 is great, but i don't seem to be able to overclock the core any higher under any memory setting without a bsod, and there's no difference in hash rate between 300 and 150, but the temp goes down alot).

I don't know if downclocking the memory will make much of a difference at all, would anyone else know?

sven

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i have 3x5850 and 1x5870 running on a corsair 800w psu
all overclocked with default voltages

joulesbeef

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moOo

If you dont want to think about it, a simple rule of thumb is 300 for the system, 200 per card. This is a bit of overkill but it will work no matter the card or overclock.

as for your system toms hardware did tests and with two, they found a draw of 469 with 1 card being 300 watts max. so 160 difference.

so for 4 cards.. 469 + 320 = 789 max watts

this is without overclock.. if you dont overvolt a 1000 watter will be fine, if you overvolt, then you probably want a 1100 or 1200 watts

Morebitcoinsplease

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You can use a 1000w PSU to handle 4x5850's I use the Antec 1000W

http://www.newegg.com/Product/Product.aspx?Item=N82E16817371012

afro25

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I've currently got 3 5850's running on a Phenom 2 x4 with 8gb RAM, on a 700w Corsair PSU.

I'm finding very conflicted information, some people seem to suggest 4 will run on a 700-750w unit while others are doing calculations of the power unit which suggest that i'd need an 850w or more.

Is anyone running a similar setup? Or could anyone test this out for me?

I have the 4th card just sitting , waiting for a PCIE x4 to x16 riser card so i can actually plug it in, but it will take a few more days to arrive, so if i need to go out and spend another £70+ on a PSU i'd rather get that done asap.

Thanks

Topic: 4x 5850 Setup, Minimum PSU needed? - page 3. (Read 6732 times)