[SOLVED] 400W PSU and GTX 1060

[thesub3001]

So I've been using for quite a while now a 1060 3gb but I've found used a very nice 1060 6gb , unfortunately it's a 1060 with an 8pin cable. The one I have is a 6 pin so it wasn't a problem. Question is how bad would it be to get a 6 pin to 8 pin adapter or molex to 8 pin but only use the 2 pins and the original 6 pin cable I have. I know neither is the most favourable but I've had the PSU for like 3 years and it had no problem with the 1060 and I seriously doubt it will have with the new 1060 it's just that they decided to make it 8 pin where as I can bet without OC they would both run at the same power.

 

[DRagor]

If your PSU does not have 8 pin PCIe cable then it is not suited for new GPU. Worked fine for 3 years you say? Fine, it paid its cost, now is the time for new PSU.
Any adapters on PCIe cable are disaster in making.

 

[hotaru.hino]

6-pin to 8-pin PCIe adapters should be treated as suspect unless you have equipment to verify the cables in the adapter can sustain 150W safely.

 

[thesub3001]

6-pin to 8-pin PCIe adapters should be treated as suspect unless you have equipment to verify the cables in the adapter can sustain 150W safely.

Actually the adapter I am more looking into is a 2xMolex to 6+2pin but only using the 2 pins on the GPU and the original 6 pins cable I have. Other thing is, I can bet you the 1060 would never draw more than 60w from the 8 pin despite requiring a 8-pin. I've looked into the GPU, it peaks at 135W during max load, remove a 75W from the mobo that leaves 60W from the 8 pin, which should be more than possible with just a 6 pin but the GPU manufacturer decided to slap 8 pin for some OCs.

 

[hotaru.hino]

Actually the adapter I am more looking into is a 2xMolex to 6+2pin but only using the 2 pins on the GPU and the original 6 pins cable I have. Other thing is, I can bet you the 1060 would never draw more than 60w from the 8 pin despite requiring a 8-pin. I've looked into the GPU, it peaks at 135W during max load, remove a 75W from the mobo that leaves 60W from the 8 pin, which should be more than possible with just a 6 pin but the GPU manufacturer decided to slap 8 pin for some OCs.

Not all video cards draw 75W from the PCIe slot then the rest from the PSU cables. For example, the RTX 2080 Super (at least this example) stopped at 56W from the slot:

Also being a little pedantic, 75W isn't from the 12V line either. The PCIe spec limits the 12V line to 5.5A, which is 66W (it can draw the remaining 9W from the 3.3V line). And the fact that the card uses an 8-pin connector here when a 6-pin would've been fine ( if we assume the card does draw 66W from the slot, that's 69W leftover over the cable, which is under the 75W limit for 6-pin connectors) tells me the power draw is biased towards the external power.

 

[thesub3001]

Not all video cards draw 75W from the PCIe slot then the rest from the PSU cables. For example, the RTX 2080 Super (at least this example) stopped at 56W from the slot:

Also being a little pedantic, 75W isn't from the 12V line either. The PCIe spec limits the 12V line to 5.5A, which is 66W (it can draw the remaining 9W from the 3.3V line). And the fact that the card uses an 8-pin connector here when a 6-pin would've been fine ( if we assume the card does draw 66W from the slot, that's 69W leftover over the cable, which is under the 75W limit for 6-pin connectors) tells me the power draw is biased towards the external power.

It's possible that it has something to do with their strive for performance on the next architecture, the 1060's graphs seem to be using around 60w from each. The current owner's rig( a friend of mine) has the gpu using just 15w over a stock 1060, it might be a close match but it's nowhere near enough of a difference to even remotely close overload 2 molexes. At least that's from what I can see. At most it will use like 10w from the adapter cable, even 20W for a 2x molex shouldn't be a problem. Still I am open for discussions but I am not looking to change PSU cuz that would be for when I decide to finally do a substantial upgrade over the 1060.

 

[DRagor]

Still I am open for discussions

Unfortunately you are not. You've made your mind and come here to find someone that will support your wrong theories. That is not going to happen. You'll do what you want, but remember my words when you fry your new GPU - you are wrong.

 

[hotaru.hino]

It's possible that it has something to do with their strive for performance on the next architecture, the 1060's graphs seem to be using around 60w from each. The current owner's rig( a friend of mine) has the gpu using just 15w over a stock 1060, it might be a close match but it's nowhere near enough of a difference to even remotely close overload 2 molexes. At least that's from what I can see. At most it will use like 10w from the adapter cable, even 20W for a 2x molex shouldn't be a problem. Still I am open for discussions but I am not looking to change PSU cuz that would be for when I decide to finally do a substantial upgrade over the 1060.

Let me back up then.

The 8-pin PCIe connector only adds two ground pins, one of which is used as a sense pin to detect if an 8-pin plug is connected or not. So the two additional pins do not provide any power, thus using a 6-pin connector in the video card and trying to fool it into thinking it has an 8-pin connector is not a good idea, as you can only assume the 6-pin cable is good for up to 75W safely. See https://en.wikipedia.org/wiki/PCI_Express#Power

You can use a 2x Molex to 8-pin PCIe connector as is, as Molex allows for up to 11A on the 12V pin, which means 132W total and it's unlikely the card will draw anywhere near that. However, that's only if the cable was properly made. Also see https://en.wikipedia.org/wiki/Molex_connector#Disk_drive

If you don't want to take any chances, the only route here is to get a PSU with an 8-pin connector already.

 

[thesub3001]

Unfortunately you are not. You've made your mind and come here to find someone that will support your wrong theories. That is not going to happen. You'll do what you want, but remember my words when you fry your new GPU - you are wrong. Not quite, I was mostly looking for someone who had actually done it and hear what he'd say. I know how it is on paper, I know the math, I know the risks. I did some math of myself decided that it's not a bad time to upgrade so instead of just 3 to 6g I just decided to get rid of my 1060 3g and I got me a 1660 super with a seasonic 650w in a package deal. For 400 euros I'd say it was a nice deal and hopefully I will get around 150-180 euros from my 1060 and old PSU. I still feel curious as to what could've happened. As a closer, I'd like to thank you all for your input.