6 to 8 Pin connector with GTX 1660TI

[TMCThomas]

Hello everyone!

I'm currently thinking about upgrading my pc, and the GTX 1660TI seems like a great option. The only problem is that my current PSU only has a 6 pin connecter. Would a cable like this (6 to 8 pin) solve the problem: https://www.newegg.com/global/nl-en/Product/Product.aspx?Item=N82E16812200420 or could it cause trouble, does anyone have experience with these? Wattage shouldn't be an issue, my current GTX 760 even draws a little more power than this GTX 1660 at 130 watts. I'm not an expert when it comes to these things so I just want to make sure that I would not run into issues because of a cable like this, Not a 100% sure what it does.

(EDIT: Or would it also be possible to just plug in the 6 pin connector without using the other 2?)

Greetings Thomas.

 

[ArbitraryAffection]

Ehm, most of the time you can just put the 6-pin straight into the 8pin and it will work. I used one of those before and it is mainly to trick the card into thinking all pins are populated, i think. I ran my 570 with 8pin with just a 6-pin plugged straight in for a while (seasonic 360W) and it was fine.

 

[TMCThomas]

Thanks!

 

[NdMk2o1o]

Hello everyone!

I'm currently thinking about upgrading my pc, and the GTX 1660TI seems like a great option. The only problem is that my current PSU only has a 6 pin connecter. Would a cable like this (6 to 8 pin) solve the problem: https://www.newegg.com/global/nl-en/Product/Product.aspx?Item=N82E16812200420 or could it cause trouble, does anyone have experience with these? Wattage shouldn't be an issue, my current GTX 760 even draws a little more power than this GTX 1660 at 130 watts. I'm not an expert when it comes to these things so I just want to make sure that I would not run into issues because of a cable like this, Not a 100% sure what it does.

(EDIT: Or would it also be possible to just plug in the 6 pin connector without using the other 2?)

Greetings Thomas.

What is the model of your PSU

 

[hat]

That cable should be fine, if just plugging the 6 pin in doesn't work.

Long ago, I also heard of a sneaky trick involving plugging a paper clip into the other two spots not populated by the 6 pin PCI-E plug. The additional 2 pins are just ground, anyway, and the paper clip (or, an 8 pin adapter) just tricks the card to thinking there's an 8 pin there.

That said, 6 pin PCI-E is rated for 75w. 8 pin, even though the two additional pins are just ground, is rated for 150w. Perhaps an 8 pin PCI-E uses beefier wires for the 3 +12v leads? Anyway, point is you could wind up pushing that 6 pin past what it was rated for... but on a card like the 1660ti, it should be fine.

 

[windwhirl]

That cable should be fine, if just plugging the 6 pin in doesn't work.

Long ago, I also heard of a sneaky trick involving plugging a paper clip into the other two spots not populated by the 6 pin PCI-E plug. The additional 2 pins are just ground, anyway, and the paper clip (or, an 8 pin adapter) just tricks the card to thinking there's an 8 pin there.

That said, 6 pin PCI-E is rated for 75w. 8 pin, even though the two additional pins are just ground, is rated for 150w. Perhaps an 8 pin PCI-E uses beefier wires for the 3 +12v leads? Anyway, point is you could wind up pushing that 6 pin past what it was rated for... but on a card like the 1660ti, it should be fine.

This may be a weird question to ask, but can the card choose where to draw power from? As in, draw 25 W (or any other amount) from the PCI-E slot and the rest from the 6 or 8 pin cable? Or is it always feeding first from one specific source, and then, as needs rise, draws power from all the other sources?

 

[Aquinus]

This may be a weird question to ask, but can the card choose where to draw power from? As in, draw 25 W (or any other amount) from the PCI-E slot and the rest from the 6 or 8 pin cable? Or is it always feeding first from one specific source, and then, as needs rise, draws power from all the other sources?

It varies from card to card. Some cards pull more off the PCIe slot than others do, even with external power via 6 or 8 pin PCIe power connectors.

 

[ArbitraryAffection]

This may be a weird question to ask, but can the card choose where to draw power from? As in, draw 25 W (or any other amount) from the PCI-E slot and the rest from the 6 or 8 pin cable? Or is it always feeding first from one specific source, and then, as needs rise, draws power from all the other sources?

That is set in the vBIOS. Actually could edit those values with my GTX 980 Ti when i bios modded it. I think 980 Ti actually introduced the fancy load balancing on the power delivery system

 

[newtekie1]

The additional 2 pins are just ground, anyway...

...8 pin, even though the two additional pins are just ground, is rated for 150w.

Sorry, but it always annoys me when I see people say this. The actual specification for the 6-pin has only 5-pins filled, two +12v pins and three ground pins. The 8-pin specification adds one more +12v pin and two more grounds. It is not just two extra grounds.

There were PSUs that used all 6 pins in their 6-pin connectors, but it wasn't a guarantee, especially on early PSUs that had 6-pin connectors.

Also, one of those extra grounds is actually a sense pin, that allows the card to detect if an 8-pin is actually plugged in. Thats why you can almost never get away with just plugging a 6-pin into an 8-pin port on the card.

 

[Vya Domus]

If your PSU only has a 6 pin it's probably not a good idea, it's circuitry is designed for a certain use case and your pushing it out of spec. This isn't about wattage, when you can't power something up due to inappropriate cables it's a sign that you should move onto something new.

 

[TMCThomas]

It's a gpu inside an oem pc, they probably choose it with the current gpu in mind which has 6 pin connection. But does that make the psu unsuitable? Is there indeed some physical limitation that would push it out of it's spec. Not to be rude or anything just curious. Because in my mind since this card is less demanding on the psu it should be better suited. More info about the psu here: http://vi.raptor.ebaydesc.com/ws/eB...7&pm=1&ds=0&t=1532700625000&ver=0&cspheader=1 otherwise I might choose for the GTX 1060 but I kind of find that a waste of money since it's currently the same price as the GTX 1660ti which is ofcourse a lot better. I could also wait for the gtx 1660 but that is rumoured to have an 8 pin connection aswell. (Would rather not change the psu, it's an option but it's kinda difficult)

 

[ArbitraryAffection]

Thats why you can almost never get away with just plugging a 6-pin into an 8-pin port on the card.

My 570 worked fine with just a 6pin plugged in to its 8 pin..

It's a gpu inside an oem pc, they probably choose it with the current gpu in mind which has 6 pin connection. But does that make the psu unsuitable? Is there indeed some physical limitation that would push it out of it's spec. Not to be rude or anything just curious. Because in my mind since this card is less demanding on the psu it should be better suited. More info about the psu here: http://vi.raptor.ebaydesc.com/ws/eB...7&pm=1&ds=0&t=1532700625000&ver=0&cspheader=1 otherwise I might choose for the GTX 1060 but I kind of find that a waste of money since it's currently the same price as the GTX 1660ti which is ofcourse a lot better. I could also wait for the gtx 1660 but that is rumoured to have an 8 pin connection aswell. (Would rather not change the psu, it's an option but it's kinda difficult)

just buy the cable and use it. the 1660Ti is extremely efficient honestly. Slot is rated for 75W and the 6 pin is 75W that is 150W total. the 1660Ti is 120W card. IDK if the card is intelligent enough to balance the load though. But honestly even though the 6 pin rated for 75W it is in reality capable of safely providing much more wattage. Maybe even 100W or more.

edit your PSU is dual 12V rail and one can do 240 and one can do 216W. it should be fine as long as CPU is using different rail to GPU

edit 2: i am not sure of this PSU though. idk the brand. Mh... IDK if it's really a good idea now. Maybe new PSU is needed here.

edit 3: as @NdMk2o1o says you should be fine to use the cable and the PSU with the 1660 Ti. enjoy the card btw^^

 

[NdMk2o1o]

My 570 worked fine with just a 6pin plugged in to its 8 pin..


just buy the cable and use it. the 1660Ti is extremely efficient honestly. Slot is rated for 75W and the 6 pin is 75W that is 150W total. the 1660Ti is 120W card. IDK if the card is intelligent enough to balance the load though. But honestly even though the 6 pin rated for 75W it is in reality capable of safely providing much more wattage. Maybe even 100W or more.

edit your PSU is dual 12V rail and one can do 240 and one can do 216W. it should be fine as long as CPU is using different rail to GPU

edit 2: i am not sure of this PSU though. idk the brand. Mh... IDK if it's really a good idea now. Maybe new PSU is needed here.

it's an FSP unit, not the latest but shouldn't have any issues powering the 1660 Ti even with a 6>8 pin adaptor, also decent PSU's with multiple rails can load balance or if dual rails generally use one for CPU and the other for GPU, FSP is a decent brand, I wouldn't have any issues running that unit with the 1660 ti and a 95w CPU. Go ahead op, get your adaptor you will be fine. /Thread

 

[ArbitraryAffection]

it's an FSP unit, not the latest but shouldn't have any issues powering the 1660 Ti even with a 6>8 pin adaptor, also decent PSU's with multiple rails can load balance or if dual rails generally use one for CPU and the other for GPU, FSP is a decent brand, I wouldn't have any issues running that unit with the 1660 ti and a 95w CPU. Go ahead op, get your adaptor you will be fine. /Thread

Sorted then

 

[newtekie1]

My 570 worked fine with just a 6pin plugged in to its 8 pin..

Then it was the exception to the rule. Most cards won't run with just a 6-pin plugged in if it has an 8-pin connector.

If your PSU only has a 6 pin it's probably not a good idea, it's circuitry is designed for a certain use case and your pushing it out of spec. This isn't about wattage, when you can't power something up due to inappropriate cables it's a sign that you should move onto something new.

What? That makes no sense, it is entirely 100% all about wattage. If the PSU can supply the wattage necessary, then it will be fine. And if it drove a GTX 760, it will have enough power for a 1660 Ti.

 

[hat]

Sorry, but it always annoys me when I see people say this. The actual specification for the 6-pin has only 5-pins filled, two +12v pins and three ground pins. The 8-pin specification adds one more +12v pin and two more grounds. It is not just two extra grounds.

There were PSUs that used all 6 pins in their 6-pin connectors, but it wasn't a guarantee, especially on early PSUs that had 6-pin connectors.

Also, one of those extra grounds is actually a sense pin, that allows the card to detect if an 8-pin is actually plugged in. Thats why you can almost never get away with just plugging a 6-pin into an 8-pin port on the card.

I wasn't aware of that. Every 6 pin PCI-E I've ever seen had 3 +12v and 3 ground, with the exception of some molex to PCI-E adapters... but, as we all know, adapters aren't always the best solution. I thought that was a limitation of molex, with two molex plugs still only offering two +12v leads.

Never knew that about the sense pin, either. If that's the case, though, how do 6 to 8 pin adapters work? Unless it works just by detecting something is there (hence the paper clip trick).

 

[newtekie1]

I wasn't aware of that. Every 6 pin PCI-E I've ever seen had 3 +12v and 3 ground, with the exception of some molex to PCI-E adapters... but, as we all know, adapters aren't always the best solution. I thought that was a limitation of molex, with two molex plugs still only offering two +12v leads.

Never knew that about the sense pin, either. If that's the case, though, how do 6 to 8 pin adapters work? Unless it works just by detecting something is there (hence the paper clip trick).

It varies from PSU to PSU, most of the good quality PSUs have 3 +12v pins, but I've seen a few cheaper ones that only have 2 +12v pins. That's why the sense pin was included on the 8-pin, so cards could actually tell if an 8-pin was used or not. Because there is actually a chance that the 6-pin on a cheap PSU could be overloaded if it only has 2 +12v pins. The sense pin is just a ground, but the 8-pin standard allows for the card to check to make sure that ground is present to make sure an 8-pin is plugged in.

 

[TMCThomas]

Thanks for all the answers! I'll post an update here when i've got the card and if it worked out

 

[John Naylor]

Definitely not a good idea (in general) ... we have seen fails in the past... not from the PSU... but the cards and PCI slots. No one remembers the RX 480 debacle ? The problem is not so much the PSU but when the card needs more than 150 watts.

The PCI Slot supplies 75 watts
The 6 pin cable supplies 75 watts

So you are good for up to 150 watts with this method. As we can see here, the MSI Gaming X 1660 Ti can pull 140 - 141 watts

https://tpucdn.com/reviews/MSI/GeForce_GTX_1660_Ti_Gaming_X/images/power_peak.png
https://tpucdn.com/reviews/MSI/GeForce_GTX_1660_Ti_Gaming_X/images/power_peak.png

So you'd be safe with that card as long as you didn't OC it. If yu intend to OC the card I certainly would not put the power limiter sider above 100%. But it is a bad habit and dangerous to post "no problem" .... while you can get away with it with a 1660 Ti, many other cards will cause problems. No one remembers the RX 480 ? What happened with the 480 was that at launch it had a 6 pin power connector. Problem was the card was drawing well over 150 watts. Being unable to get the necessary power from the 6 pin 75 watt rated cable, it was pulling that wattage thru the PC slot, exceeding its rated amperage. Hardware died.

https://www.tomshardware.com/reviews/amd-radeon-rx-480-polaris-10,4616-9.html

Subsequently, two things happened:

1. AMD issued a fix which dropped the power and amperage to the card ... that resulted in decreased performance.
2. 8 pin versions soon appeared

More reviews referenced here:
https://videocardz.com/61667/what-r...80-exceeding-pci-express-power-specifications

 

[Vya Domus]

it is entirely 100% all about wattage.

Had that been the case no PSU would ever ship with just one 6 pin. 8 and 6 pin connectors have different specifications for a reason, there is no getting around that. There a was another guy on here a while ago that tried to power a 1070 with PCIe to molex adapters and guess what he encountered issues, yet the wattage checked out. You can either use your hardware within spec or get ready for nasty surprises.

Hardware died.

No it didn't, I can't believe after so much time people still spread FUD.

 

[Susquehannock]

Connecting GPU with 4-pin molex? How many? Can be a recipe for over-loaded wires.

That said, 6 pin PCI-E is rated for 75w. 8 pin, even though the two additional pins are just ground, is rated for 150w. Perhaps an 8 pin PCI-E uses beefier wires for the 3 +12v leads? Anyway, point is you could wind up pushing that 6 pin past what it was rated for... but on a card like the 1660ti, it should be fine.

Common point of confusion. The wattages are a standard which needs to be met. Not a ceiling. The connector itself does not limit power. That is a function of the PSU. Three 18-ga wires on a 6-pin are same thing as three 18-ga wires on an 8-pin.

 

[John Naylor]

No it didn't, I can't believe after so much time people still spread FUD.

There were instances of what AMD described as "anomalous" failure, which AMD admitted in their AMA. Not in the cards as I recall but PCI slots in budget MoBos..

Connecting GPU with 4-pin molex? How many? Can be a recipe for over-loaded wires. Common point of confusion. The wattages are a standard which needs to be met. Not a ceiling. The connector itself does not limit power. That is a function of the PSU. Three 18-ga wires on a 6-pin are same thing as three 18-ga wires on an 8-pin.

6 pin does not "always" use 3 yellows ...

I was never quite sure how the amperage is controlled, that is take x from here and y from there. Worth noting tho that when you change the connector to an 8 pin, the issue of excess power being pulled from the PCI slot disappeared.

6 pin
1 12V yellow +12V
2 12V or NC, yellow, +12 V or not connect
3 12V yellow +12V
4 GND black Ground
5 GND black Ground
6 GND black Ground

8 pin
1 12V yellow +12 V
2 12V yellow +12 V
3 12V yellow +12 V
4 GND black Ground
5 GND black Ground
6 GND black Ground
7 GND black Ground
8 GND black Ground

The other problem is that folks will rad the BIOS and claim the TDP is only 100 watts. They are reading the TDP for the GPU, not the card and the power issue here was the amps coming into the card at the PCI slot, not the power being fed to the GPU.