Question Advice please -14 pins into 16 pins for GTX 1660 super

Apr 20, 2020
Hi all
the current PSU I have in a 12 year old rig is 14 pins and is currently supporting a GTX 670. I want to upgrade to GTX 1660 super (16 pins 2x8).

I have a 2x 6 pin and 1 x 2 pin. (14 pins)

After some research i can see that it might be possible use a molex adaptor. But most adapters i see have two ends for a molex with 3 pins in each molex end feeding a 8 pin for GPU. I only have 1 molex end available in the rig and not two. Does both the molex ends need to be connected? or only one?

Or i can see that the a 6 pin can be adapted to a 8 pin by one of these:

Which will give me the extra 2 pins.

Or as i also have one of the newer psu leads available inside the rig for this type connection. Is this better?

Not looking to replace PSU as i am uncertain if i can get a replacement to equal all the current required connections inside which i wont bore you all with. So looking to modify to get extra pins to work the GPU.

Some forums say i can just use the 14 and not worry about the remaining two while some advise against it.

What should i do?


Mar 16, 2013
No molex adapter.

If your current PSU does not have the proper connectors for your GPU, you simply need a new PSU that does have the required outputs.
There is no workaround on this.

Especially a 12 year old PSU.


Molex adapters are never recommended as they are fire hazards.

I wouldn't recommend using a 12-year-old PSU even if it was a good one. And if it only has an 8 pin (6+2) and a 6 pin (it's hard to guess given your broke down this a little oddly), it wasn't a good one. And yes, you need all the connectors; this isn't the extra 4-pin CPU port.

What is the exact PSU in question?
Apr 20, 2020

The rig is not broke, it works fine.

The reason i didnt provide details of PSU is because i dont know it and i cant remove it. Its over 800 w and the rig was built by a passed family member years ago. rig has
3 HHD.
4 DVD drives.
A multi port device for any type of data connector.
3 sets of USB on tower (9 usb).
A digital heat and fan speed readout.
WIFI card
Some other devices also. so the inside has a mess of Molex and the newer black flat connectors. its like a snake pit.
tower is 22 inch high. 23 inch deep and over 8 inch wide

I cannot see the model of the PSU but its against a back plate and would be difficult to remove. when i did a benchmark of the system it was still good. i just want to get a better GPU in it for my son.

upon more research t seems the GTX 1660 super only needs 8 pin and not 2x 8. So i can easily do this with a 1x 6 and 1 x 2 pin. not sure how i got to thought it was a 2x8 pin required. currently the GTX 670 is using 12 pins as its hungry.

if i were to buy a card that was 2x8 pins i guess i would just need 2 of those from my first link from a 6 pin into an 8 pin?

thank you

Math Geek

just to have one more person say the same thing.

if you do not have the right connections, then you need a new psu that does have them. the 12 year old psu was made at a time when the 12v rail was not the main power used. there was a lot more 3 and 5 volt connections back then and a lot of the possible power was on those rails. therefore, even if it is a true 800w psu, it is likely only 3-400w of that are actually 12v leads.

unlike today where most is powered by 12v rail and a quality unit will output the full power over just that rail!! those adapters are NEVER a good idea and no one here who knows anything about psu's will recommend one.

so again, if you do not have the right connections, then you need a new psu that does have them. an adapter may change how a connection looks, but it does not change voltage or create power where it does not exist.

same as putting a fat spoiler on a car and some pretty rims does not make it fast all of a sudden. the looks change but it's still the same old POS it always was where it counts :)


If you don't even know what your PSU is -- and apparently without even making any effort to find out -- then I'd give up on this upgrade because this is just the most basic of information required to upgrade your GPU responsibly. I'll keep this thread on watch just in case you have a change of heart and wish to upgrade your PC properly, but otherwise, good luck to you.