PSU advice

[siclilmonkey]

Hey

just upgraded my main pc to c2d

I have moved the old DFI SLI-DR and opty 180 in my old pc wich will replace an old AN7 and XP2800.

i can not get the DFI bored past post after reading up on the beep code it seems to be a Power problem

i have a old enemax 420w psu with a 20pin connector
i have read of another forum that the dfi boards require a "24-pin Native ATX connector PSU" and an adaptor will not work. (have tried)

i have been looking at this PSU

Corsair TX 650W ATX2.2 SLi Compliant PSU

and This one

Corsair HX 520W ATX2.2 Modular SLI Compliant PSU (CMPSU-520HXUK)

is there any other difference between these 2 psu's apart from the second being modular? and is the second worth the extra money?

i see the first one has a single 12v rail where the second one has triple 12v rails. would the 3 12v rails be any advantage over the single 12v rail?

thanks

 

[EsaT]

Both look to have internally exactly same Seasonic's high end design.

 

[Greebo]

Modular cost more but makes it much easier to make a neater case as you only connect the leads you need. However, modular wires may fall out (TAGAN have screw in ones) or are prone to introducing interference at the socket and or voltage drop wheres non-modular the wires are all hardwired into the psu so it is less likely to have interference/voltage drop.

Intel brought in split rails as it was viewed dangerous to have more than 20a on one rail so the ATX specification states all rails must be less than 20a per rail.

However, there has been a slacking off of this requirement recently and more single rail psu are been produced and some manufacturers (Tagan for one) are putting a switch on their psu's to change between split or single rail.

Pros and Cons:

Single Rail:

All power available for whatever needs it in your system (some split rails may not have enough power on that rail when the psu still has loads left spare on the other rails) so preferred by overclockers.
Downside is more likely to get cross interence with all items been on one rail

Split Rail:

Seperate "clean" power supplies for each component ensures maximum stability (note that some manufacturers cheat and in fact all the rails are joined together inside the psu anyway!)

Downside (see Single rail): If something, or several items, all need more than the power on the rail they are connecting to, your psu will reboot.

Hope that helps

 

[siclilmonkey]

thanks for all that info

1 last question

would this PSU be able to run this

Corsair VX 450W ATX PSU (CMPSU-450VXUK)

opty 170 @ 2.8ghz
2gb balistix
DFI SLI-DR
ATI x1800xt
1 hard drive
2 optical
5 fans

thanks

 

[siclilmonkey]

just ordered the Corsair HX 520W ATX2.2 Modular SLI Compliant PSU (CMPSU-520HXUK)

fingers crossed that it will sold the problem

thanks all for your help

 

[Greebo]

Goos chocie. You won't be disappointed.

 

[EsaT]

However, modular wires may fall out (TAGAN have screw in ones) or are prone to introducing interference at the socket and or voltage drop

Only thorough test I've seen about this showed no clear relation between voltage loss of PSU's cabling and type of cabling.
(of course constant plugging/unplugging would loosen contacts)

Intel brought in split rails as it was viewed dangerous to have more than 20a on one rail so the ATX specification states all rails must be less than 20a per rail.

Intel wasn't the only one involved in devising it.
It's not 20A but 240VA limit (meaning 20A on 12V) and in practise it has been removed from ATX spec for some time ago.

Split Rail:
Seperate "clean" power supplies for each component ensures maximum stability (note that some manufacturers cheat and in fact all the rails are joined together inside the psu anyway!)

None of that.
They're nothing more than current limited wire groups all coming from same source:

(but unlike in your house in PSU tripping single circuit breaker shuts down whole thing)

Only some higher power PSUs have two actual 12V transformers but in most of them their output is combined to prevent "trapped" power. (like happens in Enermax Galaxys)

 

[Greebo]

Only thorough test I've seen about this showed no clear relation between voltage loss of PSU's cabling and type of cabling.
(of course constant plugging/unplugging would loosen contacts)

Johnnyguru shows in one of his reviews that there is voltage drop and/or extra ripple but I will have to find it again in one of his 60+ reviews

Intel wasn't the only one involved in devising it.
It's not 20A but 240VA limit (meaning 20A on 12V) and in practise it has been removed from ATX spec for some time ago.

Your right but Intel was a main driving force and yes it is 240VA limit which means 20A in the UK. I forgot that more than uk people come to this forum

None of that.
They're nothing more than current limited wire groups all coming from same source:

(but unlike in your house in PSU tripping single circuit breaker shuts down whole thing)

True some are just connected with current limiters whereas as from memory some "better" psu's have seperate filters on each rail reducing the chance of cross interference. Plus there are actually psu manufacturers making some psu with totally seperate rails.