Split rails vs Combined (pooled)?

[wpcoe]

I bought a (Japanese) Abee brand "Athlete AS-600B-AR" 600W power supply, and one of its features is a switch to choose between "Split" mode and "Combined" mode.

Split mode: +12V1, +12V2, +12V3, +12V4 each rated at 26A

Combined Mode: +12V rated at 48A

Not knowing much about power supplies, what's the benefit of have four split 26A rails, vs pooling resources and having 48A available?

 

[jonnyGURU]

Sounds like an old Topower built unit with the split/combine switch.

Please read the sticky that explains how rails are split and why and what the pros and cons of each are: http://forums.anandtech.com/showthread.php?t=157583

 

[wpcoe]

Thanks for the link to the sticky thread (yeah, I didn't look for one...). Still not sure if it really matters which way I choose. I'm not doing SLI/Crossfire, so that's not a factor at least. My only concern was that I read some thread that a user was hamstrung during overclocking because his rail was limited to 18A and his processor needed more when OC'd. My rails are each rated at 26A, so I guess I should be safe leaving it "Split"?

 

[jonnyGURU]

It doesn't matter what you choose, but for safety sake leave the switch on "split". 26A per rail is more than enough.

 

[HOOfan 1]

I thought on the Topowers the switch did nothing and there was no OCP one way or the other.

 

[wpcoe]

Just now on another web site, I read an Antec-sourced article which also "encourages" use of multi-rails vs single-rail. So, next time I power down the computer, I'll crawl behind the desk and change mine to "Split" Mode. Can't argue against jonnyGURU and Antec!

 

[poofyhairguy]

Single rail is better for some things, like my mediaserver for example.

 

[jonnyGURU]

Single rail is better for some things, like my mediaserver for example.

On very rare occasions, yes. Like if you have so many drives that the load exceeds whatever the OCP may be set at, or if you're powering a TEC that draws a considerable amount of juice. But for 99% of users out there, this isn't put into practice. Most users don't use Peltiers and don' have more than four or five hard drives.

The ideal solution would be to have TWO +12V rails dedicated to drive connectors instead of just one. Unfortunately, that's rarely seen.

 

[jonnyGURU]

I thought on the Topowers the switch did nothing and there was no OCP one way or the other.

IIRC that might have been true on some models. I don't have one here to disect so I can't say for sure.