Is the -5v rail necessary anymore? Question about it on K8N-DRE.

InlineFive

Diamond Member
Sep 20, 2003
9,599
2
0
Hello everyone,

I'm looking at purchasing an Asus K8N-DRE dual-Socket 940 server motherboard for a workstation. However, when looking through the manual I see that it has a -5v rail listed for the main ATX connector. The problem arises because all of the EPS12V power supplies I can find on NewEgg and elsewhere don't support this rail anymore. Do you know why this is? Will the motherboard still work properly without any feed on it?

Thanks,

I5
 

mpilchfamily

Diamond Member
Jun 11, 2007
3,559
1
0
hasn't been needed since back when mothboards where still under ATA format and ISO was the dominant slot and PCI was a concept. PSUs havn't had a -5V rail in over a decade.
 

Interitus

Platinum Member
Jan 28, 2004
2,143
9
81
I think the only concern for the MSI K8N series and the -5v rail was that the included onboard Sound Blaster required it. I don't recall which boards had the SB audio chip, but I thought it was limited to the Platinum 939. If your board doesn't have the onboard SB audio, then it's negligible, the boards still work with other PSU's.
 

Modelworks

Lifer
Feb 22, 2007
16,240
7
76
It isn't supported anymore due to the cheap availability of -5 and -12v converters. They can now make that voltage on the board if they need it rather than having the power supply provide it. So people do not have to pay for a power supply to produce voltages they do not need.

Worst case scenario, if you do need it you could use a regular supply that has the normal 12V, 5V voltages and use a converter to supply the -5v.
Max2044 chip and a couple parts , total about $5
http://www.maxim-ic.com/quick_view2.cfm/qv_pk/1017
 
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