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Topic: PSU for 3x r9 290 without MB (Read 716 times)

newbie
Activity: 20
Merit: 0
sr. member
Activity: 364
Merit: 250
February 07, 2014, 06:32:26 PM
#8
When you say molex, do you mean this connector?



The white plug, with one single yellow wire going to it, right?
newbie
Activity: 20
Merit: 0
February 07, 2014, 06:18:53 PM
#7
I checked this out on my 4xr9 290 rig with this MB and here what i've got:
If i connect 3 card via Molex, rig wont start up.
If i connect 2 card via Molex, rig starts up normaly.

What's the difference? In both cases I use additional power cable to onboard 6pin slot for PCI-e slots
sr. member
Activity: 364
Merit: 250
February 07, 2014, 04:54:29 PM
#6
With powered risers?

Is it better to connect molex to riser?
What if this Rig works properly for few days without molex connection? Is it safe?

No, it is not safe.

As I said earlier, the engineers likely didn't imagine an end user placing such a large load on the pci-e bus (75Wx5= 375W = way more than supplemental power safely provides) You know of any molex connector safe for 375W? I sure don't.

If you overload the motherboard, you will burn it up. It is unlikely, but it could very well take your house out with it.

USE POWERED RISERS. Split the load up. It is much safer this way.
newbie
Activity: 20
Merit: 0
February 07, 2014, 04:27:37 PM
#5
With powered risers?

Is it better to connect molex to riser?
What if this Rig works properly for few days without molex connection? Is it safe?
newbie
Activity: 50
Merit: 0
February 07, 2014, 04:04:47 PM
#4
I using:
Main: 1xMSI B75a-G43
PSU: 2xGS-850 (Dual PSU)
Card: 4x290 XFX
Run to 880kh/card very good  Grin
newbie
Activity: 20
Merit: 0
February 07, 2014, 02:45:47 PM
#3
This board have additional power connect for pci-e.
I can connect them via riser with power. You think there will be no errors?
So I can easily connect 3xR9290OC GB to 1000W?

Maybe you can tell me which stuff will be best for this rig Smiley
I'am trying to get r9 290 with 3 coolers, becouse standard r9 290 is too loudly for me.
I run 4xr9 290 on this motherboard and it works good without power on risers.
My risers is x1x16.
sr. member
Activity: 364
Merit: 250
February 07, 2014, 02:21:17 PM
#2
You are going to use 5 290's on one motherboard without powered risers?

I don't know z77-mpower, but even if that board has external supplemental pci-e power I would still not try and run 5 gpus off it with unpowered risers. When the engineers were designing the motherboard I doubt they considered anyone would ever be running so many high powered cards on it, off riser cables. JMHO, I wouldn't feel safe with it in my house on unpowered risers.

I run many, many 6 290 rigs. Each has a 1.3kW supply, and a 1kW supply. I have the motherboard, all 6 powered riser cables, and three cards on 1.3kW, and three cards alone on 1kW.







newbie
Activity: 20
Merit: 0
February 07, 2014, 02:12:06 PM
#1
Hi!
I have a question for PSU, becouse I cant find stable information.

I want to connect 5x r9 290 Gigabyte OC card Wind Force to MSI z77 Mpower via unpowered risers.

My plan is:
To buy 2x1000W PSU and one will have 3xGPU and other one 2xGPU+MB

So my thinking is:
r9 290 card pull power from power supply and motherboard like this:
75 W (6-pin) and 150 W (8-pin) for max, plus 75w from MB.
My question is that combo will be enaugh ? IF yes, which PSU should i choose. I thinking of:
LEPA by ENERMAX 1000W 80+ BRONZE HASWELL or Chieftec GPM-1000C 1000W 80+ Gold Modular.

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