New Power supply. What one?

I am trying to pick a new power supply as I'm getting by on a cheep 30euro 750w one. I used a Power supply calculator and calculated myself in at around 500W but I will be adding another gfx card at some point + 1 or 2 little extras and that puts me in a tiny bit below 600W so to be safe I'm looking for a 750W or more power supply.


I'm thinking 1 of these 3 or would you have better suggestions?

http://komplett.ie/Komplett/product...h_current_gamer_hcg_900_900_watt/details.aspx

http://komplett.ie/Komplett/product..._cooling_silencer_mk_ii_750_watt/details.aspx

http://komplett.ie/Komplett/product...02/thermaltake_smart_series_750w/details.aspx

Could you list the system specs you want to run with it (including planned upgrades)?

Umm, we have a PSU forum just for you!

Up top is words saying 'STICKY'. It lists good/bad PSUs and all sorts of info for you to learn about PSUs.

Have a read. Your welcome.

Just in case, here.

http://www.overclockers.com/forums/showthread.php?t=589708

Of the bits they have, in that price range, I would get this one:
http://www.techpowerup.com/reviews/Corsair/TX750M/2.html

It's the only unit that is known to be high quality and has four PCIe power cables in case you do want to go dual GPU later.

Knufire said:

Could you list the system specs you want to run with it (including planned upgrades)?

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x2 HD 7970's
x1 usb 3.0 expansion slot
X2 2TB HDD's
x2 80G HDD's

+ possible overclocking

Bobnova said:

Of the bits they have, in that price range, I would get this one:
http://www.techpowerup.com/reviews/Corsair/TX750M/2.html

It's the only unit that is known to be high quality and has four PCIe power cables in case you do want to go dual GPU later.

Click to expand...

not true. the Antec HCG-900 (his first on the list) can quad sli/crossfire (8-pin) or dual sli/crossfire (14/16-pin).

I HAVE this PSU and it is excellent and is very solid. big drawback, unless you have a case for cable control, is that is modular. Also, if you have a massive case, you may find yourself getting an extension for the 4+4 pin CPU power. Plus, a 750 may be ****ty with all the stuff he wants to hook up. dont forget fans and pumps if he goes water...all come off that 12v rail.

Thats our PSU guru, I dont think he forgot fans or a pump (meager - most fans are less than .5A and pumps are 18-24Wish) come off the 12v rail.

Id rock 750W with a 2x 7970 setup and Intel CPU... both overclocked too, with water and several fans. In fact, for a time, I ran 2 580's on a 750W PSU... with everything overclocked... under water and 6 fans.

EarthDog said:

Thats our PSU guru, I dont think he forgot fans or a pump (meager - most fans are less than .5A and pumps are 18-24Wish) come off the 12v rail.

Id rock 750W with a 2x 7970 setup and Intel CPU... both overclocked too, with water and several fans. In fact, for a time, I ran 2 580's on a 750W PSU... with everything overclocked... under water and 6 fans.

Click to expand...

Perhaps I'm just a bit power-leery. 2 GTX 480s is enough to scare anyone into having plenty of power supply. Keep forgetting a gerbil or 2 in squirrel cages can run that intel setup with those radeon cards. I figure if my A/C isn't running 24/7, i'm in a power outage or i turned off my computer right now, just with a few windows open, my GPU's are pulling 25.5 amps.

Spot on... 2 480's are not 2 7970's (480's are like 275W each or something like that vs 2 7970's are 225W). Those are 2 gen's behind current. Power saving features are different even at idle for Nvidia stuff.. Yeah, 7970 = MUCH less than 2 480's.

EarthDog said:

Spot on... 2 480's are not 2 7970's (480's are like 275W each or something like that vs 2 7970's are 225W). Those are 2 gen's behind current. Power saving features are different even at idle for Nvidia stuff.. Yeah, 7970 = MUCH less than 2 480's.

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Yeah. I don't have the bottomless pockets you have. and even if they are 2 generations behind, I blow the crap out of most set ups for less the cost. so I pay 20 bucks a year for power. I'd rather drive a '69 vette than a 2012. I'd guarantee I'd get more looks and more poon-tang even at the cost of half the mileage per gallon. Hell, people are still using those Quadros that seriously blow nearly everything out of the water.

I turn all the power saving features off except they dial down the geometry to 400 on the main and 50 on the secondary when idle. At least the heat is manageable (30/32) at idle and really i have only seen them pull what? about 32 amps at 100 percent load oc'd at 850 (from 700).

If I had the extra 1000 bucks, I'd go with an equivalent intel/radeon setup. I just don't have that kinda cash lying around. Ran outta my lottery winnings in CALI in 1986 a long time ago - it was only $100, though, so only lasted 2 nights of drinking haha

I dont have bottomless pockets either...and Id rather drive a newer Vette without a doubt. Id like to be able to turn and all... and get 'tang that knows what car Im driving.

Quadros dont blow anything out of the water... in gaming, they are weaker in fact to their non quadro counterparts.

Oh well, I get your point(ish).

Although it is a good PSU (that corsair 750), I kinda like the idea of multiple rails. Main reason being cuz there are separate OCP. If a fan, or anything plugged into that rail, decides to lock up or goes bat-**** you aren't going to fry the whole kit 'n kaboodle. I know most don't think that has any bearing on anything, but to me it does. Plus that Corsair only has 62 amps on that single rail. why not pay 10-20 bucks more, get a 900 watt Antec HCG that comes just as highly recommended on the STICKY thread? It will last and can be used in a more power hungry system at a later date.

Now, to be honest, as an ET, in my line of work I rarely had to deal with the tiny PSU's (milspec). But, I did spend plenty of time with our 4-rail 275,000 watt water-cooled power supply. The function is the same, though. But the pieces/parts are a little more scary when you open up the door and you can smell the ozone.

The HCG is definitely not a bad unit, but like I said I'd get the corsair.
Paying more for wattage he won't use and loosing modular cables seems silly to me.

Multiple rails won't necessarily save you if a fan shorts. It has a better chance than a single rail, but you can do plenty of damage with 40a of 12v. Given a 40a rating OCP shutdown is probably in the 45-50a region, not spectacularly different than 62a. The HCG900 has ~8.8a more 12v. That's very true. Does he need it? Not really.

The HCG-900 wouldn't be a bad choice, but like I said it's not the one I would get.

Something im curious. Will it cause a short circuit or excess power drain at a critical level when a fan is blocked (by a cable or something else)? Is it dangerous, if so i will probably create some protection mechanisms.

I had a stopped fan once, but it didnt even bother to spin up at all. Then i checked out why it doesnt spin and found out that a cable was to close and might interfere. As soon as i changed the line, it was spinning properly, so obviously there was a protection mechanism. It didnt even touch the cable at all, it just stopped.


At another situation i once had a old SFF PC and the cable was hitting the main fan a little, but the fan keept spinning and made some weird noise. Anyway, i never had any damage but im still curious if it is possible to cause great damage.

Fans generally have internal protection against locked rotor situations.
If they don't, a PSU won't notice. The fan will simply continue to draw it's max startup power (typically max rated power + 20%-50%) until the fan starts turning or something in the fan dies.
Example: Intel SB heatsink fan, max rated is 0.72a (on mine, anyway), given the RPM I think that probably is the startup max. When running at full blast it's probably 0.40 to 0.50 amps.
Lock the rotor and it will briefly draw 0.72 before detecting that it's not turning, then it will go limp and wait a bit (a second or two) and then try again.
Worst case it continues trying without pause and draws 0.72a until something inside dies.
Odds are good that it ends there. If it doesn't, say if one of the controlling transistors dies short circuit to GND, it will draw as much as the very thin wires to the fan allow it to. Whether the PSU notices and shuts down or not will depend on how thick the fan wires are and how much current they can flow, if they can flow enough to hit OCP (maybe on a 20a rail, possibly on a 40a rail, I kind of doubt it on a 60a rail, and forget it on a 100a rail) then the PSU will shut down. Otherwise you'll just have a dead short, the highest resistance point of which will probably be on fire, or at least glowing, shortly.
Now if the SCP in a PSU (different than OCP, sometimes) notices the sudden short, even though the short can't actually sustain enough current to hit OCP, it may shut down.
There's a lot of black magic and voodoo involved in PSU protections, I can't claim to understand all of it in detail.

So it is possible to have a blocked fan cause serious destruction, but you have to have a number of things:
1) A blocked fan.
2) No protections inside the fan (fairly rare).
3) The fan guts actually overheat (possible, but not likely with normal fans).
4) It manages to die with a short circuit. (Very unlikely)
5) The PSU doesn't notice. (Unlikely, varies by PSU)

In theory, it's possible. In reality? I'd be awfully surprised.

I'll have to make up a test rig and see if some of my larger PSUs will trip SCP with super thin wire or not. That'd be another one not to try at home.