Graphics Cards with *two* 6-Pin Power-Connectors

[LoRd_MuldeR]

Okay, I already asked this at the German board, but couldn't get a clear answer. So I ask again: I'd like to obtain a new Graphics Card in the near future. But I noticed that nowadays almost any Graphics Card has got two 6-Pin power connectors. I already found out that both power connectors must be connected. Unfortunately my PSU has got exactly one 6-Pin connector for Graphics Cards. Now the question: Do I need to buy a new PSU or can I use an adapter? Or more specifically: Is my 450 Watt PSU sufficient for a Graphics Card of the current generation? It's a Chieftec GPS-450AA, if that matters...

[onesloth]

What CPU do you have? What GPU do you want to get? How many hard drives does your systems have?

You're definitely pushing it using a 450w supply with a high-end system.

[Ma-Xell]

If 450 watts is enough for the gfx card, then you can use one of these (http://www.ocforums.com/attachment.php?attachmentid=62665&stc=1&d=1203189446.jpg).
If not then then you need a new psu.

[burfadel]

Not all graphics cards need 2 6 pins, only the really high end cards of the generation. If anything but the highest of the high end cards require 2x6pin, I wouldn't buy it simply because it would have to be inefficient. The only cards I'd expect to see the 2x6 pins are the 4870X2 or the gtx 285/295.

[LoRd_MuldeR]

What CPU do you have? What GPU do you want to get? How many hard drives does your systems have?

You're definitely pushing it using a 450w supply with a high-end system.

Please see "My Specs" in my signature :)

If 450 watts is enough for the gfx card... If not then then you need a new psu.

That's what I'm trying to figure out right now. So what do you guys think?

[LoRd_MuldeR]

Not all graphics cards need 2 6 pins, only the really high end cards of the generation. If anything but the highest of the high end cards require 2x6pin, I wouldn't buy it simply because it would have to be inefficient. The only cards I'd expect to see the 2x6 pins are the 4870X2 or the gtx 285/295.

Well, to me it seems almost all cards of the current generation have got two 6-Pin power connectors.

Right now I'm planning to get a Nvidia GeForce GTX260. And all the cards I see have two power connectors. The same applies to the current ATI Readeon generation.

So it's definitely not limited to high-end cards. I think only "low-end" cards have one single power connector nowadays...

[ash925]

IMO you should buy a new PSU because with a quad core and a GTX 260 you are really going to be pushing your PSU to the limits when playing any of the latest games.
Hope these help:
http://www.guru3d.com/article/geforce-gtx-260-review/4
http://www.tomshardware.com/reviews/nvidia-gtx-280,1953-25.html

[LoRd_MuldeR]

The monitoring device is reporting a maximum system wattage peak at roughly 302 Watts, and for a PC with this high-end card, that is not excessive at all.

So with my 450 Watt PSU I should be on the safe side, right? :confused:

A GeForce GTX 260 requires you to have a 500 Watt power supply unit at minimum if you use it in a high-end system.

Why is that? First they say that the peak wattage is at 300 Watts, then they recommend a 500 Watt PSU at least.

That makes a difference of 200 Watts. Is really so much headroom required? :eek:

Also my Q6600 isn't exactly a "high-end" system. So I'm still not sure whether I need a new PSU or not...

[DJ Bobo]

@ Lord Mulder
PSUs shouldn't get loaded with more than 50% if you want them to stay "cool and quiet" (I'm too much into AMD, I know :D)
So you should stay under 230W with your PSU under load.
Take 105W for your CPU and 50W for the other components, this leaves you with 75W for the GPU. So ideally you would like to get a graphics card with no connector, like the Radeon HD4670 for example.

BUT! if your PSU is of very good quality and stays quiet even at higher loads, you may load it up to 80%, so up to 360W, which means you can put whatever single GPU card but the GTX280, so the GTX260 should be alright (this one consumes up to 180W, so the whole computer will stay under 340W)

The middle way would be getting a card with only one connector like the Radeon HD4850 which consumes up to 100W, this should be ok, even if your PSU isn't very good.
If you have the XTX version of the X1950 and were happy with the PSU until now, go ahead and get the HD4850, cause the XTX consumes a little bit more ;)

[burfadel]

Well, to me it seems almost all cards of the current generation have got two 6-Pin power connectors.

Right now I'm planning to get a Nvidia GeForce GTX260. And all the cards I see have two power connectors. The same applies to the current ATI Readeon generation.

So it's definitely not limited to high-end cards. I think only "low-end" cards have one single power connector nowadays...

I was thinking of the Radeon 4850's, even the 1gb factory overclocked ones. They only require 1 6 pin power connectors. Thats all a 450W power supply should be used with anyway, if you want to use a higher video card, regardless of the connectors, a higher output PSU would be highly advisable!

[LoRd_MuldeR]

if you want to use a higher video card, regardless of the connectors, a higher output PSU would be highly advisable!

That will be the way to go then :rolleyes:

:thanks:

[onesloth]

http://www.tomshardware.com/reviews/nvidia-gtx-280,1953-25.html

@Mulder: The above articles shows the GTX260 needing 270w at full load. The Q6600 had a TDP of 95w. That leaves only 85w of your 450w for the rest of your system. Like I said: pushing it.

You just won't know *for certain* until you plug everything in. If your system becomes unstable, you need a bigger supply.

[LoRd_MuldeR]

Okay. I think I will go with a new PSU then. What do you think: Is 500 Watt sufficient or is 550 Watts advisable?

http://www.alternate.de/html/product/Netzteile_bis_600_Watt/Chieftec/GPS-500AB/160197/
http://www.alternate.de/html/product/Netzteile_bis_600_Watt/Chieftec/GPS-550AB/160199/

[ash925]

I'd advise a 550W unless the price difference from 500W is unacceptable(unable to open links for some reason).It is always nice to have a bit of a headroom.

[LoRd_MuldeR]

I'd advise a 550W unless the price difference from 500W is unacceptable(unable to open links for some reason).It is always nice to have a bit of a headroom.

The links work for me. The difference is 10€.

Anyway, I read that an overdimensioned SPU isn't a very good idea either, as it would run with bad efficiency...

[Shinigami-Sama]

Well, to me it seems almost all cards of the current generation have got two 6-Pin power connectors.

Right now I'm planning to get a Nvidia GeForce GTX260. And all the cards I see have two power connectors. The same applies to the current ATI Readeon generation.

So it's definitely not limited to high-end cards. I think only "low-end" cards have one single power connector nowadays...

the 260 needs both
just installed one in a friends PC and found that out the hard way
3 unhookd zap straps later and we got the second 6 pin

also theres 8pin -2x6pin adapters that come with the cards now as well

but I'd say get a least a 650W anyways, thats what the 280 I have recommends...

[DJ Bobo]

@ onesloth
His Q6600 is the B3 one, with 105W TDP... and the 270W in the review are for the whole system :p

@ Lord Mulder
Not 500 and not 550 if I were you, this is not a real upgrade compared to 450. I would recommend the 720W PSU (http://www.alternate.de/html/product/Netzteile_ueber_600_Watt/Tacens/Radix_III_720/316268/?tn=HARDWARE&l1=Energie&l2=Netzteile&l3=%C3%BCber+600+Watt) from that shop, once and for all. With an old Q6600 and a GTX260 on board, you won't have to worry about "underloading" it *lol*

[LoRd_MuldeR]

Maybe that one?
http://www.alternate.de/html/product/details.html?articleId=212893&

Seems to be quite popular...

[Shinigami-Sama]

http://www.newegg.ca/Product/Product.aspx?Item=N82E16817139006
I'm getting this one, pretty cheap with that rebate...

that coolmaster doesn't that bad though

[Ma-Xell]

I have an OCZ StealthXStream 600W, its very cheap and OCZ is not a bad brand.

http://www.newegg.ca/Product/Product.aspx?Item=N82E16817341010
$87.99 = 64.5629 EUR

[DJ Bobo]

@ Lord Mulder
80€ for 720W and 85% efficiency, or 85€ for 620W and 80% efficiency, I think the choice is obvious ;)

[swaaye]

Yeah you should probably grab a new PSU with dual connectors if you want to use a graphics card that needs that much power.

One thing to consider is whether you even want a GPU that uses that much power. It will also be a small furnace. And as it ages, it'll be slower than new stuff yet still be a power-sucking furnace. Better off going with a slower GPU that's also less of a hog IMO.

Tom's Hardware actually did a fantastic article on GPU power consumption and power connections. A rare thing for them to put out such a nice article.
http://www.tomshardware.com/reviews/geforce-radeon-power,2122.html

@ Lord Mulder
80€ for 720W and 85% efficiency, or 85€ for 620W and 80% efficiency, I think the choice is obvious ;)

Just remember that efficiency is guaranteed at percentages of power output. The 80+ rating is tested at 20, 50, and 100% output. You're best off getting the lowest power output PSU you can go with because the idle power level is likely to be more efficient then. Of course, you're even better off finding a review of the PSU that actually tests its efficiency at a wide range of loads.

Good roundup.
http://www.anandtech.com/casecoolingpsus/showdoc.aspx?i=3516

Unless the OP's considering doing some crazy SLI setup with cards that have 2x PCIe power connectors each, a 720W is overkill. I'd suggest something more along the lines of 500-600W. Any quality PSU that has 2x PCIe power.

[DJ Bobo]

The efficiency below 20% load isn't a problem, since the consumption is low by default. If we suppose that his PC consumes 100W idling, this means 125W at the plug with 80% efficiency and 133W with 75% efficiency, that's nothing compared to what the PC sucks at full load (kinda hypocritical to care about 8W difference at idle when you suck 300W at load).

And as said before, you generally don't wanna load your PSU with more than 50%, unless you want to turn it into a turbine. Very few models manage to stay cool and quiet at higher loads (you can count them on one hand, and they're very expensive for their wattage).
So the 720W model shouldn't be loaded with more than 360W, where a 500W shouldn't be loaded with more than 250W, not enough for the setup he's looking for.
With the 720W, he has a little head room if he ever upgrades to a CPU with a higher TDP or a graphics card with a higher consumption, it's not that much, really (think 900W+ for a dual GPU setup ;))

So keep in mind: always read 50% of the nominal wattage ;)

[LoRd_MuldeR]

Okay, I see. I'll maybe get one of these:
http://www.alternate.de/html/product/Netzteile_ueber_600_Watt/be_quiet!/Straight_Power_BQT_E6-650W/295148/?tn=HARDWARE&l1=Zubehör&l2=Netzteile
http://www.alternate.de/html/product/Netzteile_ueber_600_Watt/Cooler_Master/Silent_Pro_M700/273297/?tn=HARDWARE&l1=Zubehör&l2=Netzteile

650/700 Watts and 52/50 Amperes on the 12V line. That should be sufficient ;)

[DJ Bobo]

@ Lord Mulder
If I had to choose between only those two, the Silent Pro will be my friend :)

[deets]

hmm interesting. I just got a 260 (216, xfx overclock) on my 500watt PSU. I also have a q6600. this psu has one pcie connector and the card came with a 4 molex to 6 pin adapter. the cpu is also over clocked a bit to 2.8.

no obvious signs of any issues in x264 or heavy gaming.

[DJ Bobo]

no obvious signs of any issues in x264 or heavy gaming.

One of two things:
1) your PSU is one of the rare ones that stay quiet even at higher loads
2) Your PC is getting so loud under load that you're not noticing that the PSU is struggling :p

[LoRd_MuldeR]

hmm interesting. I just got a 260 (216, xfx overclock) on my 500watt PSU. I also have a q6600. this psu has one pcie connector and the card came with a 4 molex to 6 pin adapter. the cpu is also over clocked a bit to 2.8.

no obvious signs of any issues in x264 or heavy gaming.

According to this (http://www.tomshardware.com/reviews/geforce-radeon-power,2122-6.html) article it's not very surprising for a "good" 500 Watt PSU. The article says that the PSU must be able to cope with 20-25 Amperes on the 12V rail for a "current" PC. I guess your's is more in the 25 Amperes range then (overclocked, etc). As long as your PSU can deal with that, you will be fine. Some cheap 500 Watt PSU's can only handle ~17 Amperes in the 12V rail, which would be a problem here!

Look at this one, for example:
http://www.alternate.de/html/product/Netzteile_bis_600_Watt/be_quiet!/Dark_Power_PRO_550W/272585/?tn=HARDWARE&l1=Zubehör&l2=Netzteile

It has "only" 550 Watts, but four separate 12V rails, where each can handle up to 20 Amperes - altogether 44 Amperes can be handled on the 12V rails. That should be more than enough.

[DJ Bobo]

The loudness of a PSU has nothing to do with how many amperes it can handle though ;)

[LoRd_MuldeR]

The loudness of a PSU has nothing to do with how many amperes it can handle though ;)

Well, that's right. However I don't really care if it gets a bit louder under load, as I wear a headset anyway when in gaming mode :D

[DJ Bobo]

Well, that's right. However I don't really care if it gets a bit louder under load, as I wear a headset anyway when in gaming mode :D

Well, why bother buying a new PSU then? if you don't care about the noise, your current 450W PSU will do just fine :devil:

[LoRd_MuldeR]

Well, why bother buying a new PSU then? if you don't care about the noise, your current 450W PSU will do just fine :devil:

Nope. Only 17 Amperes allowed on the 12V rail. That not sufficient :o

Also the GeForce GFX260 eats +70 Watts under full load, compared to my Radeon 1950XT. Consequently upgrading from 450 to 550 Watts PSU gives my an additional headroom of ~30 Watts.

Finally using two separate 12V rails for the GPU where each can handle up to 20 Amperes should be much more stable than putting everything on one 12V rail specified for 17 Amperes...

[DJ Bobo]

I don't understand well how things work with those 12V lines, but you have 14+15A on both 12V lines (these should add together, shouldn't they?!), so what's the problem?

[LoRd_MuldeR]

I don't understand well how things work with those 12V lines, but you have 14+15A on both 12V lines (these should add together, shouldn't they?!), so what's the problem?

But my PSU doesn't expose the two separate 12V lines. Remember: Only one single 6-Pin connector! So I have to assume that one 12V line is connected directly to the Mainbaord/CPU (ATX-Connector), while the other line is used for the rest (the 6-Pin graphics card adapter and the drive connectors). Now if I use an adapter in order to get the second 6-Pin connector, which is required for the graphics card, the graphics card would be connected to one single 12V rail only! For a GTX260 card that means a current of up to 15.9 Amperes, but my PSU's 12V line is only specified for 14/15 Amperes. This can't be very safe...

[DJ Bobo]

OK, here's what I understood:
these line values are garbage, the only thing that matters is the total capacity, which is 29A in your case.
Afaik, all lines share the capacity dynamically, so you don't need to worry about one line getting overloaded or something.

[LoRd_MuldeR]

OK, here's what I understood:
these line values are garbage, the only thing that matters is the total capacity, which is 29A in your case.

Where is that info from? And can you be sure that it applies to all the PSU's in existence? :confused:

[DJ Bobo]

I got that from SilentPCReview (http://www.silentpcreview.com/article28-page3.html).
Notibly:
PSU makers' specs are misleading in that they rate the current capacity of each 12V rail independently. What really matters is the total 12V current: Generally, up to 20A is available on any one 12V line assuming the total 12V current capacity of the PSU is not exceed

[LoRd_MuldeR]

Well with that logic the info that my current PSU has one 14A line and one 15A line doesn't say much. The total maximum Amperes for the 12V lines would matter - unfortunately that information isn't listed.
But if you look at other PSU's then you'll notice that the total Amperes for the 12V lines (the number that matters) usually is less than what you'd get when simply summing up the individual lines.
Consequently I must assume that altogether my PSU supports less than 14+15 Amperes. At the same time the "be quiet!" 550W PSU supports a total 12V current of up to 44 Amperes. That should be enough.

[DJ Bobo]

I think that, whenever they don't tell you the total amperage, you assume that it's the total of all the line values.
Because I only saw specific total values when the total is less than the total of the lines.
If you saw the table on that page I told you about, you'll see that these line values are pretty much a joke:
A PSU rated for 32A max on the 12V lines can be labelled many different ways:

* 12V1: 18A, 12V2: 14A
* 12V1: 17A, 12V2: 15A
* 12V1: 16A, 12V2: 16A
* 12V1: 15A, 12V2: 17A
* 12V1: 14A, 12V2: 18A

It could be marked 20A + 12A, but being a cautious bunch, the engineers will probably not specify more than 18A on any one line. This gives 2A headroom to allow some room for error for the current limiting circuit
I especially enjoyed their remark in this review (http://www.silentpcreview.com/Chill_Innovation_CP-700M):
4 x 12V Rails | Who really cares?
:D

[LoRd_MuldeR]

I think it matters, even if you can't push all the rails to their individual maximum at the same time (as that would exceed the total limit). It matters if you need a lot of Amperes for a single device, most important the GPU. Even if your PSU can handle enough total 12V current for the GPU, you may not be able get all the required current trough one single 12V rail, as that would exceed the rail's limit. And I think that's exactly the reason why the current generation graphic cards have two 6-Pin connectors. So we can divide the load on two separate rails...

[DJ Bobo]

The only reason you'll find 2 6-pin connectors is that the card consumes more than 150W, because the PCI-E connector can deliver up to 75W and one 6-pin connector can also deliver up to 75W. You won't ever find 2 connectors on a card that draws less than 150W.
For example, the HD4850 and the GeForce GTS250 both need less than 150W, that's why you'll find only one connector on them, where the HD4870 and the GTX260 both need more than 150W, that's why you'll find 2 connectors on them. On the other hand, you'll find one 6-pin connector and one 8-pin connector on an HD4870X2 or GTX280, because they draw more than 225W (the 8-pin connector can deliver 150W by itself).

So it has nothing to do with dividing power over as many rails as possible, it's about specs, that's all.
You see, the 720W unit above has "only" 2 rails, yet it has 2 connectors, one of which is a 8-pin connector. If it was about having one rail on each connector, it would have had at least 3 rails ('cause one 8-pin would count for two 6-pin)

Anyway, I do recommend to upgrade the PSU but just because it will get too loud (and then as you already noticed, I would recommend a substancial upgrade, not a mere 50 or 100W update), but in your case, I see absolutely no reason to upgrade, I'm confident your PSU should be able to handle a Q6600 and a GTX260.

[Blue_MiSfit]

I'd say for your config - a Q6600 and a GTX 260+, you should have at least 30-32 amps of +12V power. That's a hair under 400w. I'd imagine your current PSU would work perfectly fine with one PCIe 6 pin native cable, and one via adapters. It's possible you might over-stress one of the +12V rails if you chose the wrong molex plugs to wire into this adapter, but I doubt it.

If you're worried about headroom and efficiency, then an upgrade is definitely in order. I usually err on the side of caution when it comes to PSUs - but only gently :) No need for more than 550w for the vast majority of users.

I'm a big fan of Corsair power supplies, personally. They're all modular, and are built by an excellent OEM. I forget which, but all the reviews are excellent, and I've run the 520w model for over a year now on the following system:

Q6600 @ 3 GHz
Asus P35 chipset Motherboard
8GB DDR2
5 HDDs
2 Optical drives
Radeon 4830 512MB
5x 120mm fans

I actually ran with a GTX260 for awhile - I was "testing" it for a customer :p. I had no issues with power whatsoever.

Also, the Corsair PSUs are just plain pretty, and are obviously high quality just by the weight and finish. It's a high quality product, plain and simple. Nothing at all like unboxing a generic 300w tin-can :p

Do keep in mind the enormous physical size of new midrange / high end graphics cards! The 260 is simply massive, and I had to remove some of my hard drives, as the card physically blocked several of my SATA ports!!

~MiSfit

[LoRd_MuldeR]

Do keep in mind the enormous physical size of new midrange / high end graphics cards! The 260 is simply massive, and I had to remove some of my hard drives, as the card physically blocked several of my SATA ports!!

Not sooo much bigger than my current one:

http://img5.imageshack.us/img5/7825/comparek.jpg

[Shinigami-Sama]

yeah the gtx 260 I installed for my friend is simply massive
it barely fit in my friends mid tower

[burfadel]

Yeah some of them don't fit in to smaller cases, especially when you consider an extra few CM for the power plugs on the end of the card, and especially if the HDD's are exact opposite the card (which they will be in most cases) and their connectors)!

[LoRd_MuldeR]

Fortunately I found a system with my case (Cooler Master Centurion 534) that ships with a GeForce GTX 260 card:
http://www.alternate.de/pix/prodpic/450x450/s/s8iv41_2.jpg

(Note that power plugs are now located on the side of the card, which slightly reduces the problem)

[Blue_MiSfit]

Indeed. Just mind the SATA connectors ;)

Oh, and enjoy your new GPU!

~MiSfit

[swaaye]

And as said before, you generally don't wanna load your PSU with more than 50%, unless you want to turn it into a turbine.

That's why you look up reviews that test PSUs at various load levels for both efficiency and noise. Like that Anandtech roundup that I linked to. Or JonnyGuru. Or Tech Report.

A friend of mine bought a 1000W OCZ PSU that was on sale and cheap. It's a jet engine regardless of the load you put on it. Has a 120mm fan at probably 2500 RPM full time. He didn't read reviews. Got what he paid for with that "bargain" kW PSU. ;)

I recently replaced a Antec Earthwatts 385W in my Phenom II X4 940 @ 3.3 GHz + Radeon 3850 system. It was perfectly stable, but it got loud when loaded up. So I picked up a PC Power & Cooling Silencer 420W (reviewed in a low watt roundup at Anandtech). It is almost as quiet at full load as at idle. It's barely audible. The system fully loads about at ~230W AC, idles at ~70W AC.

The biggest PSU I own is a 650W that's in my Intel Q6600 + 8800 GTX system. I blew lots of cash for a Antec Signature 650W. That is another very quiet PSU, but I don't really believe that it's worth its premium. It is an awesome PSU though....

[LoRd_MuldeR]

Anyway, who needs 1000 Watts for a Desktop system? Even a Quadcore CPU with one of the latest high-end GPU's won't need that much...

[Shinigami-Sama]

Anyway, who needs 1000 Watts for a Desktop system? Even a Quadcore CPU with one of the latest high-end GPU's won't need that much...

with just one GPU you don't need more than a 750W
but put a second, or third in....

throw in a couple 15k drives too and bam, >700W