Would PSU w Active PFC help OC?

[Killmenow]

HI, im currently using a PSU without PFC (see sig). My processor and ram both overclock horribly. I was wondering if it could be my PSU. How much would PFC help? Oh, and i also have a few wires and whatnot behind the mobo and the mobo tray.......would they cause any problems??? (I notice alot of buzzing when using integrated sound..............EMI???)

 

[JohnAn2112]

The only place that needs Active PFC is Europe because of their uncontrollable power spikes. In Canada and the US, Active PFC would do nothing.

 

[Killmenow]

Thx, guess ill stick with this PSU then.

What about cables behind mobo??? are they safe??? can they cause major EMI???

 

[superHARD]

no cables would not do that (well mabye, do you have 6ft of your power cord coiled inside your computer?) even then I doube it would do much.

 

[imported_Kensai]

Active PFC sounds pretty too, don't forget about that. 🙂

 

[mdcrab]

Don't PSU's w/Active PFC operate at a higher efficiency, costing less to operate over the long run? Or is this just a bunch of bunk?

mdcrab

 

[imported_michaelpatrick33]

My Seasonic 600 with active PFC is rated at 80% efficiency. It does help.

 

[furballi]

You're not going to save any $ with PFC in a US residential home environment. There is also NO advantage when it comes to the quality of the output voltages.

Look for the efficiency rating on the PSU if you want to save $. The high-end Enermax, OCZ, and Seasonic PSUs should run at +75% efficiency.

 

[imported_Starman]

No, but adjustable rails would 😉

The OCZ Powerstream PSUs do not have active PFC and they are great for overclocking :thumbsup:

 

[Mark R]

Don't PSU's w/Active PFC operate at a higher efficiency, costing less to operate over the long run?

Yes, and no.

PFC in itself doesn't improve efficiency of the power supply - what it does is put less strain on the power grid for the same amount of power transferred - a non PFC PSU needs more Amps for the same number of Watts, compared to a PFC PSU.

In most places you pay for Watts, and not the amps needed to deliver those Watts - so PFC on it's own won't save you money. However, factories and large offices are sometimes billed for both amps (actually volt-amps) and Watts. I believe this is also very common in Taiwan. If you pay for volt-amps as well as Watts, then PFC (any kind) will save you money.

On a smaller scale PFC reduces stress on in-building wiring, allowing more PCs to be used on each circuit. There have been cases where offices have burned down due to borderline wiring installs which were overstressed by non-PFC computer PSUs. But again, PFC on its own doesn't actually save you energy.

Now, there is a way in which *active* PFC can save energy, and improve efficiency - the problem is that it requires a PSU redesign.

If you are lazy, you can just bolt an active PFC circuit onto an old PSU design. You get a marketing gimick, but very little practical benefit. Arguably, your PSU becomes even less efficient because the active PFC circuit needs some energy to operate.

However, active PFC circuits have a very handy side effect - they provide very smooth regulated power. Non active-PFC PSUs have to be designed to operate under both over-and-under voltage conditions (potentially as low as 90V and as high as 135V) to accomodate this voltage range the efficiency has to be compromised. If the PSU is redesigned to take advantage of active PFC (which produces a constant voltage) then a considerably more efficient design can be used.

The first batch of Active PFC PC PSUs (like the Antec truepower among others) appear to fall into the first category. However, most new (24 pin ATX) active PFC PSUs tend to fall into the latter.

 

[madthumbs]

I just upgreaded psu's from Antec 430W Truepower to a 500W Smartpower.

I could not get a Barton 2500+ on an Asus A7N8X Deluxe or an AMD64 3000+ on an A8V Deluxe to OC at all with the 430W. Infact, getting both stable at stock speeds was a chore! Now I have it in my AMD64, and am OC'ing from stock 1800MHz to 2295MHz w/o changing htt, or anything other than fsb. (255x9) Prime95 stress tested for 6 hours w/ no erros. Check connections on integrated sound, or check for irq conflicts.