Hello, i'm going to buy geforce gtx 670 and it uses 2 6-pin pci-e cables. i have 1. now I have now a geforce gtx 280 and it uses 1 6-pin and 1 8-pin. and the 8-pin is connected with an adaptor to a molex (2 molexes actually). now my reasoning is that the 8-pin draw more power (read it somewhere) so an adapter from 2 molexes to 6-pin pci-e should do the job, right? i'm running a SP-ATX-550WTR-IR as a psu (crappy, but so far did the job and i'm tight on budget)
a question about PSU connectors
- Thread starter matanyabs
- Start date
Solution
- Apr 22, 2009
- 43,150
- 411
- 131,790
I have no idea what that PSU is, but if it only has 1 x 6 pin PCIe connector, chances are it wasn't designed to run a card that requires 2. However, if you want to use it anyway, and since the GTX 280 drew more load than the GTX 670 will, go ahead and use the Molex adapter... at your own risk.
Yes,
6 pin adds 75W capacity
8 pin adds 150W capacity
Yes,
6 pin adds 75W capacity
8 pin adds 150W capacity
thank you, another question. apperantly the 670 uses 1 8-pin connector (it comes with an adapter of 2 6-pin to 1 8-pin). as i said i have a 6-pin and 8-pin (the 6-pin is from the psu, the 8 pin is with the adaptor). should I use the 8 pin from the molex? or should i buy a 2 molex to 6 pin adapter and than use the 2 6 pins that i'm gonna have? (6+molex -> 6+6 -> 8) or am i pushing ot too far?
- Apr 22, 2009
- 43,150
- 411
- 131,790
The power is all coming from the same +12V source. All you are providing is the current carrying capacity of the wires and connectors. Most GTX 670s are 170W cards and require 2 x 6 pin PCIe connectors. What is the make/model of GTX 670 you are going to use?
- Apr 22, 2009
- 43,150
- 411
- 131,790
Above, you said you were getting a card that used 2 x 6 pin. But that card uses 1 x 8 pin. Is this the card?
http://i1.rozetka.ua/goods/8755/282216_8755938.jpg
- Apr 22, 2009
- 43,150
- 411
- 131,790
You should edit your post then.
If your PCIe power cable is a 6 +2 pin, you can use it. If it is a 6 pin only, you will have to use the Molex to 8 pin adapter instead.
Or you can use the 6 pin with one of these: http://www.newegg.com/Product/Product.aspx?Item=N82E16812200420
But you'd be better off using the Molex adapter. Well... not better off... less unsafe.
- Apr 22, 2009
- 43,150
- 411
- 131,790
The 170W (TDP) GTX 670 only draws ~14A @ +12v maxed out.
The std. 4 pin Molex connector from the PSU has a 11A limitation per pin.
You need to tell me how many yellow wires the 6 pin cable has and their wire gauge. But, I'm guessing it's either 2 x #18 awg or #20 awg yellow wires. That will be 16A per wire or 11A per wire depending on the size. More than likely, you'd be safer with the single 6 pin to 8 pin adapter.
- Oct 15, 2014
- 18,020
- 2,335
- 101,590
the problem is he does not have 2 6 pins to adapt into a single 8 pin. he would be using a molex to 6 pin adapter and then using that with the 1 6 pin he has to merge into the 8 pin.
since he has already been using the molex to 8 pin successfully, i would suggest to keep using it and not try the daisy chain of adapters the other method uses. just seems better to me when it is not recommended to use the adapters anyway. so using 2 sets of adapters in a daisy chain just seems like tempting fate a bit too much
since he has already been using the molex to 8 pin successfully, i would suggest to keep using it and not try the daisy chain of adapters the other method uses. just seems better to me when it is not recommended to use the adapters anyway. so using 2 sets of adapters in a daisy chain just seems like tempting fate a bit too much
- Apr 22, 2009
- 43,150
- 411
- 131,790
I didn't suggest he do that. I suggested he use his single 6 pin PCIe with this adapter to feed the GTX 670's single 8 pin header: http://www.newegg.com/Product/Product.aspx?Item=N82E16812200420
That way he will be dividing the current between the pair of yellow #18 or #20 wires on the PCIe power cable. The PSU's Molex only has a single yellow (+12v) wire of questionable size and the Molex connector's pins are only rated for 11A.
Neither solution is ideal, and I doubt the PSU is designed for that kind of load anyway. But if it survived the GTX 280, it should handle the GTX 670.
That way he will be dividing the current between the pair of yellow #18 or #20 wires on the PCIe power cable. The PSU's Molex only has a single yellow (+12v) wire of questionable size and the Molex connector's pins are only rated for 11A.
Neither solution is ideal, and I doubt the PSU is designed for that kind of load anyway. But if it survived the GTX 280, it should handle the GTX 670.
- Oct 15, 2014
- 18,020
- 2,335
- 101,590
how does that adapter work? how does it take a single 75w input and output a 150w one? i guess this is why i misunderstood you cause i never considered such a thing.
can you explain how this works as it sure seems like it could not. this is not a sarcastic statement but an honest question.
can you explain how this works as it sure seems like it could not. this is not a sarcastic statement but an honest question.
- Apr 22, 2009
- 43,150
- 411
- 131,790
It doesn't change the capacity of the connection. It simply provides the necessary pins to make the card work. It provides +12V to the necessary inputs of the card. The connection is still only rated for 75W.
This is another option the OP can go with if he has 2 Molex free: http://www.amazon.com/Molex-PCI-E-Express-Converter-Adapter/dp/B00FHLQO9I
This is another option the OP can go with if he has 2 Molex free: http://www.amazon.com/Molex-PCI-E-Express-Converter-Adapter/dp/B00FHLQO9I
- Oct 15, 2014
- 18,020
- 2,335
- 101,590
ok that is what i thought would happen. so how does the card get the power it needs if it is only getting 75w, will it even work? i realize the mobo also provides 75w but would 150w be enough when the tdp of the card is about 170w?
- Apr 22, 2009
- 43,150
- 411
- 131,790
Watts are a function of volts (+12) times the current draw of the card at any moment; Volts * Current = Watts (in a DC circuit).
If the GTX 670 never reaches 100% usage, it is likely to never consume the full 170W (TDP) it is rated for. My guess is that the OP's CPU can't keep up with the card enough to get it to 100% usage. Hence, it will never consume 170W. But again, not enough information.
And if the card did manage to draw 14.167 amps (170W @ +12V), the PSU will continue to provide that if it can. The wires will get hotter, the connections will get hotter of course. Eventually something will fail if it consumes the full 170W continuously.
Obviously, the ideal situation would be to get a PSU designed to handle the card and the rest of the system.
If the GTX 670 never reaches 100% usage, it is likely to never consume the full 170W (TDP) it is rated for. My guess is that the OP's CPU can't keep up with the card enough to get it to 100% usage. Hence, it will never consume 170W. But again, not enough information.
And if the card did manage to draw 14.167 amps (170W @ +12V), the PSU will continue to provide that if it can. The wires will get hotter, the connections will get hotter of course. Eventually something will fail if it consumes the full 170W continuously.
Obviously, the ideal situation would be to get a PSU designed to handle the card and the rest of the system.
TRENDING THREADS
-
News US sanctions transform China into legacy chip production juggernaut — production jumped 40% in Q1 2024- Started by Admin
- Replies: 33
-
-
Question New pc build r9 7900x3d rtx 4080 super no post only ram rgb turns on- Started by Harvey Durward
- Replies: 5
-
-
-
RTX 4070 vs RX 7900 GRE faceoff: Which mainstream graphics card is better?
- Started by Admin
- Replies: 72
Facebook
Twitter
Instagram