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ArcSpark · 29th Mar 2008, 02:42

This should be a simple question to answe, but I can't seem to find any numbers via google

The system I'm trying to get running stable has a bit of a power problem with the PSU. I did some digging and found out why. The MB specs recommend a lot of 12v current from 4 rails. The PSU I have only has 3 12v rails, and can't source the current.
Here is what the specs say I need:
12v1 18A peak, 12v2 18A peak, 12v3 14A, 12v4 8A 3.3v 24A, 5v 24A, -12v 3.5A peak, 5V standby 3.5A.

These numbers are worse case and chances I won't get to them and even though all that totals up to close to 1KW, I've seen 700W supplies that advertise they can do this. They are not priced too badly either. Systems built specifically around this board can do it with power supplies under 700W, but they are using a much more basic video card and the PSUs are rather custom (and hard to find). So I'm trying to find something off the shelf.
I figure the current supplied through the x16 slot is already factored into the board's numbers, but what about the PCIe 6 pin connector?

review_hunter · 29th Mar 2008, 11:56

1KW? You've got more than enough power to handle a 7950GT/GX2.

Are you overclocking? It would be helpful if you list out your full system specs.

badders · 29th Mar 2008, 13:22

Also, What Brand/Model PSU is it?

Splynncryth · 29th Mar 2008, 16:43

oops, too mahy windows open, didn't mean to post here.

ArcSpark · 29th Mar 2008, 16:45

OK, heres the setup, but it's a little nuts
The video card in question is an EVGA 7950gt KO superclocked
MB is s5000xvnSATA
CPUs are e5350s
RAM is 1 pc2-5300 1GB FB dimm untill I have things shaken down. I am trying to see if I can get multiple PC2 6400 DIMM later
HD is a maxtor stm3500630as
Undecided on the optical drive, but I'm not sure it matters.
it's in an Antec Titan 650 chassis (the only one I could confirm positively that it could handle the board)

The PSU is the Antec Truepower that came with the case. Initially, it worked, but the board won't post now (the fans spin, but no post code on the built in LEDs). I borrowed a PSU and found that is where the problem lies.

For cooling, I have a set of evercool cooljag PWM fans, 1 120mm, 2 92mm, and 1 80mm. I bought these after a little research into what Intel ships with their systems. Hopefully, it will make the BMC happy and it will run them quietly.

The technical product spec on Intel's site is where I got the numbers from.

Looking back over this though, i may be suffering from something of a knee jerk reaction. The CPUs are rated at 80W, the NB at ~25W, I think about 12W for the SB (based on TDP since I can't find any other number), go highball on the RAM and say 10W, ~17W for all the case fans, and ~another 27W for the CPU fans.
I have not pinned down firm wattage numbers for the video card, but the highest I was stated 82w for the GPU. I don't know if that included RAM, and how the clocking of the card affects things, but say an unscientific 90w for some fudge factor.

A 650 sounds like it should be capable of running all this. The problem I've found is with the 12v rails, there just isn't enough current available. If I did some juggling initially, I got the system to run. I was trying to test the setup before looking into the PSU problems more closely when I ran into this problem. So I wnat to resolve the power issues once and for all.

29th Mar 2008, 02:42	#1
ArcSpark Did I let the magic smoke out? Join Date: Jan 2008 Posts: 75	7950 current draw? This should be a simple question to answe, but I can't seem to find any numbers via google The system I'm trying to get running stable has a bit of a power problem with the PSU. I did some digging and found out why. The MB specs recommend a lot of 12v current from 4 rails. The PSU I have only has 3 12v rails, and can't source the current. Here is what the specs say I need: 12v1 18A peak, 12v2 18A peak, 12v3 14A, 12v4 8A 3.3v 24A, 5v 24A, -12v 3.5A peak, 5V standby 3.5A. These numbers are worse case and chances I won't get to them and even though all that totals up to close to 1KW, I've seen 700W supplies that advertise they can do this. They are not priced too badly either. Systems built specifically around this board can do it with power supplies under 700W, but they are using a much more basic video card and the PSUs are rather custom (and hard to find). So I'm trying to find something off the shelf. I figure the current supplied through the x16 slot is already factored into the board's numbers, but what about the PCIe 6 pin connector?

29th Mar 2008, 16:43	#4
Splynncryth 0x665E3FF6,0x46CC,... Join Date: Dec 2002 Location: USA Posts: 1,509	oops, too mahy windows open, didn't mean to post here. Last edited by Splynncryth; 29th Mar 2008 at 16:46. Reason: oops, posed in wrong thread

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29th Mar 2008, 11:56	#2
review_hunter Minimodder Join Date: Mar 2008 Posts: 25	1KW? You've got more than enough power to handle a 7950GT/GX2. Are you overclocking? It would be helpful if you list out your full system specs.

29th Mar 2008, 16:45	#5
ArcSpark Did I let the magic smoke out? Join Date: Jan 2008 Posts: 75	OK, heres the setup, but it's a little nuts The video card in question is an EVGA 7950gt KO superclocked MB is s5000xvnSATA CPUs are e5350s RAM is 1 pc2-5300 1GB FB dimm untill I have things shaken down. I am trying to see if I can get multiple PC2 6400 DIMM later HD is a maxtor stm3500630as Undecided on the optical drive, but I'm not sure it matters. it's in an Antec Titan 650 chassis (the only one I could confirm positively that it could handle the board) The PSU is the Antec Truepower that came with the case. Initially, it worked, but the board won't post now (the fans spin, but no post code on the built in LEDs). I borrowed a PSU and found that is where the problem lies. For cooling, I have a set of evercool cooljag PWM fans, 1 120mm, 2 92mm, and 1 80mm. I bought these after a little research into what Intel ships with their systems. Hopefully, it will make the BMC happy and it will run them quietly. The technical product spec on Intel's site is where I got the numbers from. Looking back over this though, i may be suffering from something of a knee jerk reaction. The CPUs are rated at 80W, the NB at ~25W, I think about 12W for the SB (based on TDP since I can't find any other number), go highball on the RAM and say 10W, ~17W for all the case fans, and ~another 27W for the CPU fans. I have not pinned down firm wattage numbers for the video card, but the highest I was stated 82w for the GPU. I don't know if that included RAM, and how the clocking of the card affects things, but say an unscientific 90w for some fudge factor. A 650 sounds like it should be capable of running all this. The problem I've found is with the 12v rails, there just isn't enough current available. If I did some juggling initially, I got the system to run. I was trying to test the setup before looking into the PSU problems more closely when I ran into this problem. So I wnat to resolve the power issues once and for all.