4x 5850 Setup, Minimum PSU needed?

[afro25]

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

[Morebitcoinsplease]

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

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

[joulesbeef]

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

[sven]

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

[afro25]

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?

[afro25]

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?

[m3sSh3aD]

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]

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.

[krzynek1]

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]

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

[m3sSh3aD]

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.

the 850 was a cheap nasty one for 60 quid. give.it a go fried in 2 mins ha ha. now I use xfx 750 and a basic 650. what was to hand

as i said, a decent kilowatt one will be more than enough

[sven]

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

all 5800 cards pretty much use the same amount of power assuming the same voltages and clocks are being used
the 5870 is the most efficient one

[ed64]

1000 is probably a good idea, need to keep it below 80% load or so, to maintain peak power efficiency...

[PLaci1982]

Not only the load, but the energy-efficiency are also important!

If you want a Corsair, buy one "Professional Series Gold" series, but I would also recommend Cooler Master's Silent Pro Gold series...

I would recommended 1000-1200W for higher efficiency.

Edit: They have the best feature for mutly-GPU:

Single 12 V Power Rail
Tackling challenges from the most power-intensive peripherals head on, this solitary 12 V power rail provides ample power and strong resistance to any overloading.

[krzynek1]

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

Code:

Adapter 0 - ATI Radeon HD 5800 Series
                            Core (MHz)    Memory (MHz)
           Current Clocks :    915           360
             Current Peak :    915           360
  Configurable Peak Range : [550-1200]     [200-1400]
                 GPU load :    99%

Adapter 1 - ATI Radeon HD 5800 Series
                            Core (MHz)    Memory (MHz)
           Current Clocks :    940           360
             Current Peak :    940           360
  Configurable Peak Range : [550-1200]     [200-1400]
                 GPU load :    99%

Adapter 2 - ATI Radeon HD 5800 Series
                            Core (MHz)    Memory (MHz)
           Current Clocks :    900           360
             Current Peak :    900           360
  Configurable Peak Range : [550-1200]     [200-1400]
                 GPU load :    99%

Adapter 3 - ATI Radeon HD 5800 Series
                            Core (MHz)    Memory (MHz)
           Current Clocks :    955           360
             Current Peak :    955           360
  Configurable Peak Range : [550-1200]     [200-1400]
                 GPU load :    99%

im powering them with 2x fortron fsp650-80egn per rig

[echo2]

i would stick to an 1250 if u overclocked some cards

[haploid23]

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

hey i have almost the same exact setup. running 3x 5850 and 1x 5870 all overclocked, one 5850 overvolted, using a OCZ 850w gold efficiency. it draws about 750w from the wall.

[ChrisLandin]

Could someone please tell me how to overclock my 5850's past the 775 core that is max setting in CCC

Manythanks

[polymorpher]

I suggest you to buy a power metre, which can be found in most computer shops (or shopfront of electricity company), cheap and accurate, and you can avoid wasting tons of money on expensive PSU.

[Kermee]

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

That seems high.  My 4x5830 Sapphires with clocks at 998/300 are 640W-650W at the wall with a Kill-A-Watt meter.

Cheers,
Kermee