asrock b85m-itx and corsair cx500 power supply

[glantern30]

hello, Im in the process of building my first gaming computer and i'm looking for a little assistance. I've purchased the motherboard and powersupply listed above, and they are suppose to be compatible. However the problem is when I try to test to see if I can get the power supply to turn on nothing happens. I think the problem is that the asrock b85m-itx instruction says it has an 8-pin ATX12V1 even though when you look at it there's only 4 pins. And the corsair cx500 power supply comes with 1 x 4+4 Pin EPS 12V.

Now per the instructions on the motherboard it says:
"This motherboard pro-
vides an 8-pin ATX 12V
power connector. To use a
4-pin ATX power supply,
please plug it along Pin 1
and Pin 5".

I have no idea what this means and I think this is where my problem lies. I'm checking to see if anyone has ever used these two componets in their builds?? Any help with greatly be appreicated, this is my first gaming pc build and what a pain I tell ya lol. And again both of these components per there websites are compatible but I haven't a clue to get them to work.

 

[Dark Lord of Tech]

That power supply isn't Haswell compatible.

 

[glantern30]

I'm assuming that means it wont work...

 

[Dark Lord of Tech]

It's not compatible with the low power sleep states of the Haswell platform.

 

[glantern30]

I don't understand why the website said it was compatible??? it also sad the corsair 430cx was compatible will this one work??

 

[Dark Lord of Tech]

Corsair:

All power supplies that use DC-to-DC conversion to power their 3.3V and 5V rails have no problem with Haswell's new low-power state, Corsair says. The following Corsair power supplies all use DC-to-DC conversion and are listed as "100% compatible with Haswell CPUs":

AXi: AX760i, AX860i, AX1200i
AX (Gold and Platinum): AX650, AX750, AX760, AX850, AX860, AX1200
HX (Silver, Gold and HX1000): HX650, HX750, HX850, HX1000, HX1050
TX-M (All Versions): TX550M, TX650M, TX750M, TX850M, TX950M
TX (All Versions): TX550, TX650, TX750, TX850, TX950
GS (Current V3): GS600, GS700, GS800
GS (Legacy V1): GS600, GS700, GS800
CX-M: CX750M
CX: CX750
VX: (Legacy) VX550

 

[glantern30]

this is greek to me which power supply should I buy? I found this pc gaming build online of forbes website and it said the corsair 430cx would work I just pick a bigger supply to be safe. it was the nivida mini pc gaming build for 650

 

[Dark Lord of Tech]

Haswell Ready and made by SEASONIC.

PCPartPicker part list / Price breakdown by merchant

Power Supply: XFX TS 550W 80+ Bronze Certified ATX Power Supply ($59.99 @ Newegg)
Total: $59.99
Prices include shipping, taxes, and discounts when available

Or if your on a Budget.

PCPartPicker part list / Price breakdown by merchant

Power Supply: EVGA 500W 80+ Bronze Certified ATX Power Supply ($29.99 @ Newegg)
Total: $29.99
Prices include shipping, taxes, and discounts when available

 

[glantern30]

ok thanks I'll send this one back. it sucks I can't find a supply local no a days I gott wait now

 

[Dark Lord of Tech]

Look for Haswell Certified\Ready ON THE SPECS.

 

[glantern30]

nice thank you so much for the quick response... is it worth checking a local radio shack or best buy for a supply

 

[Dark Lord of Tech]

Best Buy maybe , not Radio shack.

 

[geofelt]

I think the text is wrong. You have a 4 pin cpu slot and a 8 pin power lead. Half of the 4+4 power lead will be left dangling; that is ok. The psu lead will fit only one way, do not force anything.

How are you trying to turn on the psu?
Normally you would momentarily touch the two PWR-SW pins on the front panel header.

Do you have a cpu/ram/ monitor installed?

You should be OK even without haswell compatibility. It means that certain low power sleep states are not available to you. They are not really necessary.

 

[glantern30]

the cpu is plug into fan slot 1 on the board. and the 4 pin into the 8-pin ATX 12V with the other 4 dangling. its going into the coolermaster elite 110 case we had the power connected to the case so me and my brother. turn on the case and the power to the back of the corsair

 

[geofelt]

You need to plug the cpu cooler fan into the port labeled cpufan1. Otherwise, you may not start.

 

[glantern30]

I will double check but I believe thats where I have it. there is another spot on the board that I didnt try maybe I picked the wrong slot

 

[Dark Lord of Tech]

Haswell compatibility with Corsair power supplies
By Jonny Gerow



When an Intel Core (i3, i5, i7) processor is idle, it goes into a sleep state that requires less power than when the CPU is active. Since the motherboard voltage regulation modules that provide power to the CPU gets their power from the power supply's +12V rail, these sleep states can dramatically reduce the load on the power supply's +12V rail.

According to Intel's presentation at IDF, the new Haswell processors enter a sleep state called C7 that can drop processor power usage as low as 0.05A. Even if the sleeping CPU is the only load on the +12V rail, most power supplies can handle a load this low. The potential problem comes up when there is still a substantial load on the power supply's non-primary rails (the +3.3V and +5V). If the load on these non-primary rails are above a certain threshold (which varies by PSU), the +12V can go out of spec (voltages greater than +12.6V). If the +12V is out of spec when the motherboard comes out of the sleep state, the PSU's protection may prevent the PSU from running and will cause the power supply to "latch off". This will require the user to cycle the power on their power supply using the power switch on the back of the unit.

While we are still working with Intel on the details of the testing methodology they use to check PSUs for Haswell compatibility, it is already known that a power supply that uses DC to DC for the non-primary rails (the +3.3V and +5V) will not have an issue with the new low power sleep states. This is because a DC to DC buck converter is used to convert +12V to +3.3V and +5V. This means that no matter what load the CPU puts on the power supply, there will always be a load on the +12V because the +12V is required to provide power to +3.3V and +5V.

Corsair utilizes this DC to DC technology in most of their power supplies. Starting with the CX750 and CX750M and moving all of the way through the GS Series, TX and TX-M Series, the HX Series, both the AX Series Gold and AX Series Platinum, and the new AXi Series. So whatever your budget, if you choose Intel's new Haswell processor and wish to utilize the new, low power C7 sleep state, Corsair has a power supply for you.

 

[glantern30]

what does all that mean???? so the corsair 500cx will work then??

 

[glantern30]

I just confirmed it is compatible

http://www.pc-specs.com/psu/Corsair/Corsair_CX500_V2_500W/47/Compatible_Motherboards