[SOLVED] I need a new PSU for the RTX 3070 Ti?

[juoza]

Hi Everyone, hope you're well. This is so bloody confusing, I keep getting conflicting advice on what I can and can't do. I wanted to originally use my CS750M power supply for the Gigabyte 3070 Ti OC Vision, except I don't have 2 seperate PCI-E ports on my PSU, so I can't use my PSU. I have a section called "PCI-E 6+2 & 4+4 CPU" but I got told that I can use the 4+4 for the GPU and others told me I can't so, I'm completely confused.

Either way, I need a new PSU and was looking at getting the Corsair CX750M. My spec specs are the following:

Intel core i5 6600k - Overclocked to 4.2ghz
16gb of DDR4 2400mhz Hyperx ram
1 ssd at 256gb and 1 hdd at 1tb
z170 pro gaming motherboard

My question is, will this Corsair CX750M PSU be compatible with my motherboard? I heard that the "type 4" PSU's have a different ATX 24 pin connector, apparently the "pinout" is different, but I have no idea what they mean by "pinout". My CS750M PSU came with "type 3" cables.

Lastly, in the image attached, is this the right place to plug in 2x PCI-E cables to power my graphics card? https://ibb.co/f8XVCQ0

The image I sent, the labeling is so confusing. It says "PCIE / CPU" so can I plug both CPU and PCIE cable in there since the ports are the exact same just upside down?

 

[Aeacus]

but I got told that I can use the 4+4 for the GPU

You're free to try and use 4+4 12V EPS to power your GPU. However, you will fry the GPU since the pins on the other end of the cable are different, compatible only with 12V EPS port on your MoBo. So, if you don't trust the net, try it out yourself and find it out the hard way.

My question is, will this Corsair CX750M PSU be compatible with my motherboard?

Compatible? Yes.
Is it good enough build quality to power RTX 3070 Ti? Nowhere near of that.

CXm PSUs, at best, are mediocre quality PSUs, and only good to power office PC without dedicated GPU. But to power gaming PC, with expensive GPU, a lot better build quality PSU is needed. That is, if you care about your hardware and doesn't want to risk cheap PSU frying it.

Good quality PSU to look for, is either Seasonic Focus+, Seasonic PRIME, or if you're Corsair fan, then RMi, RMx, HX, HXi or AX series. In 750W range.
(Btw, all three of my PCs are powered by Seasonic, full specs with pics in my sig.)

Keep in mind, that the PSU is the most important component in the PC, since it powers everything. And you do not want to cheap out on PSU. Due to that, you can cheap out on every other component, except PSU.

I heard that the "type 4" PSU's have a different ATX 24 pin connector, apparently the "pinout" is different, but I have no idea what they mean by "pinout". My CS750M PSU came with "type 3" cables.

Type 3 and Type 4 cables are to do with the power cables that come with PSU. Those have different pinout on PSU's side, but on system's side, all pinouts are same. There is no "unique" 24-pin 12V connectors that go to MoBo.

So, if what you currently have, are Type 3 power cables, then when you get a new PSU, you must use those power cables that come with new PSU, and not your old power cables. Using wrong, incompatible power cables with PSU, will fry the PSU and most likely the hardware as well, what the PSU is supposed to power.

Lastly, in the image attached, is this the right place to plug in 2x PCI-E cables to power my graphics card? https://ibb.co/f8XVCQ0

Yes.

It says "PCIE / CPU" so can I plug both CPU and PCIE cable in there since the ports are the exact same just upside down?

While the +12V rail has combined port to power either GPU or CPU, the cable that is used to plug into the GPU or CPU power socket, is different. So, if you want to use the port on PSU to power GPU, you have to use power cable labeled as PCI. But if you want to use the port to power CPU, you have to use power cable labeled CPU or EPS.

 

[KyaraM]

I wouldn't pick that PSU either. Did you check the PSU tier list on this forum? They list recommendations for high-end systems.

Btw, I'm using a BeQuiet! Straight Power 11 750W with my own 3070Ti. It's listed in A-Tier. No issues so far, can recommend, and the labeling is really self-explanatory with the GPU ports being labeled VGA. You also only need one cable for all pins since each cable is 2x 6+2. But in the end, I would look at that list and then decide on which high-end PSU is eight for you I guess... don't just buy one because either of us tells you to.

Article - [psucultists] PSU tier list rev. 14.8 (Final Update Jul '21)

PSU Tier List 4.0 rev. 14.8 (outdated) Last Update: 12-07-2021 Legend : Gray - EoL/obsolete and/or otherwise not recommended for purchase. Green - small form-factor (gold and blue colors are disregarded due to scarcity of SFX PSUs) Gold - best units in the tier (includes requirements for blue...

forums.tomshardware.com

 

[juoza]

You're free to try and use 4+4 12V EPS to power your GPU. However, you will fry the GPU since the pins on the other end of the cable are different, compatible only with 12V EPS port on your MoBo. So, if you don't trust the net, try it out yourself and find it out the hard way.



Compatible? Yes.
Is it good enough build quality to power RTX 3070 Ti? Nowhere near of that.

CXm PSUs, at best, are mediocre quality PSUs, and only good to power office PC without dedicated GPU. But to power gaming PC, with expensive GPU, a lot better build quality PSU is needed. That is, if you care about your hardware and doesn't want to risk cheap PSU frying it.

Good quality PSU to look for, is either Seasonic Focus+, Seasonic PRIME, or if you're Corsair fan, then RMi, RMx, HX, HXi or AX series. In 750W range.
(Btw, all three of my PCs are powered by Seasonic, full specs with pics in my sig.)

Keep in mind, that the PSU is the most important component in the PC, since it powers everything. And you do not want to cheap out on PSU. Due to that, you can cheap out on every other component, except PSU.



Type 3 and Type 4 cables are to do with the power cables that come with PSU. Those have different pinout on PSU's side, but on system's side, all pinouts are same. There is no "unique" 24-pin 12V connectors that go to MoBo.

So, if what you currently have, are Type 3 power cables, then when you get a new PSU, you must use those power cables that come with new PSU, and not your old power cables. Using wrong, incompatible power cables with PSU, will fry the PSU and most likely the hardware as well, what the PSU is supposed to power.



Yes.



While the +12V rail has combined port to power either GPU or CPU, the cable that is used to plug into the GPU or CPU power socket, is different. So, if you want to use the port on PSU to power GPU, you have to use power cable labeled as PCI. But if you want to use the port to power CPU, you have to use power cable labeled CPU or EPS.

Thanks for that! I'm changing my mind to the 850 watt EVGA supernova G5, cause the labeling on corsair is <mod edit language> and it doesn't specify what is 4+4 and what is pci e. Whereas EVGA says "Vga1" which is for GPU. unless I'm mistaken. Is this a good PSU?

Also how did you know that the image I sent, that's where the PCI-e goes and not the CPU cable? It's not clear. The port for the "pcie / cpu" looks the exact same just upside down. So seems like the pcie and cpu port would fit each other on psu side?

 

[KyaraM]

Thanks for that! I'm changing my mind to the 850 watt EVGA supernova G5, cause the labeling on corsair is <Mod Edit> and it doesn't specify what is 4+4 and what is pci e. Whereas EVGA says "Vga1" which is for GPU. unless I'm mistaken. Is this a good PSU?

Also how did you know that the image I sent, that's where the PCI-e goes and not the CPU cable? It's not clear.

That's a B-Tier PSU, more for mid-range systems. Would go with A-Tier for a high-end system. See the link I posted above.

 

[juoza]

That's a B-Tier PSU, more for mid-range systems. Would go with A-Tier for a high-end system. See the link I posted above.

Will do, my pc build is more mid range these days since it's old though. Only high end thing is the gpu. I might do a full pc upgrade in future but wanna see if this card works with my setup fine first.

 

[juoza]

That's a B-Tier PSU, more for mid-range systems. Would go with A-Tier for a high-end system. See the link I posted above.

I looked at all those PSU's but the connectors are confusing on some.

 

[juoza]

You're free to try and use 4+4 12V EPS to power your GPU. However, you will fry the GPU since the pins on the other end of the cable are different, compatible only with 12V EPS port on your MoBo. So, if you don't trust the net, try it out yourself and find it out the hard way.



Compatible? Yes.
Is it good enough build quality to power RTX 3070 Ti? Nowhere near of that.

CXm PSUs, at best, are mediocre quality PSUs, and only good to power office PC without dedicated GPU. But to power gaming PC, with expensive GPU, a lot better build quality PSU is needed. That is, if you care about your hardware and doesn't want to risk cheap PSU frying it.

Good quality PSU to look for, is either Seasonic Focus+, Seasonic PRIME, or if you're Corsair fan, then RMi, RMx, HX, HXi or AX series. In 750W range.
(Btw, all three of my PCs are powered by Seasonic, full specs with pics in my sig.)

Keep in mind, that the PSU is the most important component in the PC, since it powers everything. And you do not want to cheap out on PSU. Due to that, you can cheap out on every other component, except PSU.



Type 3 and Type 4 cables are to do with the power cables that come with PSU. Those have different pinout on PSU's side, but on system's side, all pinouts are same. There is no "unique" 24-pin 12V connectors that go to MoBo.

So, if what you currently have, are Type 3 power cables, then when you get a new PSU, you must use those power cables that come with new PSU, and not your old power cables. Using wrong, incompatible power cables with PSU, will fry the PSU and most likely the hardware as well, what the PSU is supposed to power.



Yes.



While the +12V rail has combined port to power either GPU or CPU, the cable that is used to plug into the GPU or CPU power socket, is different. So, if you want to use the port on PSU to power GPU, you have to use power cable labeled as PCI. But if you want to use the port to power CPU, you have to use power cable labeled CPU or EPS.

I'm thinking then getting this one

https://www.amazon.com.au/CORSAIR-C...cphy=9071723&hvtargid=pla-1415659957571&psc=1

I'm surprised price is same as CX series. hopefully the cable connectors have a guide.

 

[tecmo34]

@juoza Yes, the Corsair RM850X is a good power supply and you'll be fine with that and give you some head room on the power requirements.

 

[ProfSeaGoat]

I would grab the MSI AGF 850, it has a promotion for Assassins Creed Valhalla + Dawn of Ragnorak DLC. Is also cheaper. https://www.msi.com/Promotion/assassins-creed-valhalla-dawn-of-ragnarok-game-bundle

https://www.jw.com.au/msi-mpg-a850gf-850w-atx-power-supply-unit-483365

I just did this myself.. great PSU. I run an RTX 3070.

 

[logainofhades]

I looked at all those PSU's but the connectors are confusing on some.

What is confusing about it? 6+2 are for PCI-E, the 4+4 is for the additional CPU power. Connector is usually on the top left, of the motherboard.

 

[Aeacus]

Also how did you know that the image I sent, that's where the PCI-e goes and not the CPU cable? It's not clear. The port for the "pcie / cpu" looks the exact same just upside down. So seems like the pcie and cpu port would fit each other on psu side?

Best way to describe why on PSU side, the port is labeled PCIE/CPU, is these two following images of similar example:

Upper image is USB-A (rectangular connector) to USB-C, while lower image is USB-A to micro USB.

Now, both of these cables can be connected to USB-A port, but since the end of the cable is different between the two, they are meant for different devices.
Very same is true with PSU's PCIE/CPU port. The port is same, but the cable that connects to it is different. For GPU, it is 6+2 PCIE and for CPU it is 4+4 EPS. Do you get it now?

I looked at all those PSU's but the connectors are confusing on some.

Further reading about PSU connectors,
link: http://www.playtool.com/pages/psuconnectors/connectors.html

I'm thinking then getting this one

https://www.amazon.com.au/CORSAIR-C...cphy=9071723&hvtargid=pla-1415659957571&psc=1

RM850x is a good PSU. Comes with 10 years of warranty, among other things. It's also one of the Corsair units i suggested above.

 

[juoza]

What is confusing about it? 6+2 are for PCI-E, the 4+4 is for the additional CPU power. Connector is usually on the top left, of the motherboard.

Because the port on the psu, i heard that the port for 4+4 cpu draws 12 volts which is different to the 6+2. The ports are the EXACT same from what i can see on the PSU, but apprently the voltage is different. Not too sure.

 

[juoza]

Best way to describe why on PSU side, the port is labeled PCIE/CPU, is these two following images of similar example:

Upper image is USB-A (rectangular connector) to USB-C, while lower image is USB-A to micro USB.

Now, both of these cables can be connected to USB-A port, but since the end of the cable is different between the two, they are meant for different devices.
Very same is true with PSU's PCIE/CPU port. The port is same, but the cable that connects to it is different. For GPU, it is 6+2 PCIE and for CPU it is 4+4 EPS. Do you get it now?



Further reading about PSU connectors,
link: http://www.playtool.com/pages/psuconnectors/connectors.html



RM850x is a good PSU. Comes with 10 years of warranty, among other things. It's also one of the Corsair units i suggested above.

It sort of does. This is the back of the PSU of the rm850x, and it says same thing with the 6+6 & 4+4. All the ports are the same but people kept telling me that "you can't plug the PCIE cable in the 4+4 connector" something like that. So you're saying that i can plug in the pcie cable in ANY of those 8 pin connectors? https://ibb.co/Dp8BR3m

Or my current PSU the CS750M has the same thing, but are you saying i could plug in 2 pcie cables in the 6+2 and 4+4 port "on" the psu? or does 6+2 and 4+4 not relate to the port on the psu but on the motherboard / gpu?

 

[Karadjgne]

The port at the psu means absolutely nothing, zero, nada. It's just a connection. It's not 8pin or 6pin or even 12pin, it's just a physical location to plug in the necessary wires.

What means Everything is what's on the business end of those cables. A pcie 6+2 is an adaptable 6pin that can be used if required as an 8 pin pcie. A 4+4 is EPS, it's sole purpose is to help power the cpu. While both technically add upto 8pins, the pinout is opposite. The pcie will have ground pins on top row and power pins on bottom row, whereas EPS will have power pins on the top row and grounds on the bottom. So if trying to cram either in the wrong port, you'll be putting 12v into the ground, and running power in the back door to the cpu or gpu. At which point you had better pray you bought a very good psu with every level of protection and those protections are sensitive enough to actually work and save your equipment.

The reason to Never use old cables is simply that you have absolutely no idea which connection is which at the psu. That port could have power pins on one side, and grounds on the other, power in center pins and grounds outside or up/down, so tracing the wires physically, the other end will not have power at its correct pins. Damages ensue.

So you plug your pcie wire into the port that says pcie. EPS/CPU wire goes into EPS/CPU. What you end up with is exactly no different than the old fashioned psus with full solid cables. The only difference between those and a modular psu is the ability to unplug unnecessary wires.

Think about a simple 4pin molex connector. Red-black-black-yellow. That's at the connector, every molex is like that. At the psu it could be black-red-yellow-black and the wires will cross in the middle to be the correct orientation at the molex. If you use old cables from a different psu, that connection could have flat cables, r-b-b-y, so your psu puts 5v to red, black is ground and yellow is 12v. With the old cables what you'd get is red ground, black 5v, black 12v, yellow ground, the wires not physically connecting to the correct pins regardless of color. Same applies to every connection at the psu, the wires need to be physically located at the correct pins.

 

[Aeacus]

Or my current PSU the CS750M has the same thing, but are you saying i could plug in 2 pcie cables in the 6+2 and 4+4 port "on" the psu? or does 6+2 and 4+4 not relate to the port on the psu but on the motherboard / gpu?

6+2 and 4+4 matter only on the MoBo/GPU side, since on the PSU side, both cables have the same connector that goes into PSU.

Karadjgne above also explains it quite well. But here's another round of explanation;

PSU side ----------cable---------> port at the end

8 pin port -------------------------> 6+2 pin PCIE = fits only GPU
8 pin port -------------------------> 4+4 pin EPS = fits only MoBo to power CPU

 

[--SID--]

Hi Everyone, hope you're well. This is so bloody confusing, I keep getting conflicting advice on what I can and can't do. I wanted to originally use my CS750M power supply for the Gigabyte 3070 Ti OC Vision, except I don't have 2 seperate PCI-E ports on my PSU, so I can't use my PSU. I have a section called "PCI-E 6+2 & 4+4 CPU" but I got told that I can use the 4+4 for the GPU and others told me I can't so, I'm completely confused.

Either way, I need a new PSU and was looking at getting the Corsair CX750M. My spec specs are the following:

Intel core i5 6600k - Overclocked to 4.2ghz
16gb of DDR4 2400mhz Hyperx ram
1 ssd at 256gb and 1 hdd at 1tb
z170 pro gaming motherboard

My question is, will this Corsair CX750M PSU be compatible with my motherboard? I heard that the "type 4" PSU's have a different ATX 24 pin connector, apparently the "pinout" is different, but I have no idea what they mean by "pinout". My CS750M PSU came with "type 3" cables.

Lastly, in the image attached, is this the right place to plug in 2x PCI-E cables to power my graphics card? https://ibb.co/f8XVCQ0

The image I sent, the labeling is so confusing. It says "PCIE / CPU" so can I plug both CPU and PCIE cable in there since the ports are the exact same just upside down?

So you want to downgrade from CS750M to CX750M? It's not a good move.

On the CS750M you can use both 8 pin sockets fot PCI-e and CPU because the pinout (on which pin the PSU is connected internally. 3,3v, 5v, 12v, 5vsb, ground, sense. PCI-e and CPU use 12v and ground only)) and the shape of the pins is the same. (same for any Corsair since 2014) But CS750M can be 8+ years old and the quality is not that good. Better replace it for a more decent PSU. RM850x is very good.

 

[juoza]

The port at the psu means absolutely nothing, zero, nada. It's just a connection. It's not 8pin or 6pin or even 12pin, it's just a physical location to plug in the necessary wires.

What means Everything is what's on the business end of those cables. A pcie 6+2 is an adaptable 6pin that can be used if required as an 8 pin pcie. A 4+4 is EPS, it's sole purpose is to help power the cpu. While both technically add upto 8pins, the pinout is opposite. The pcie will have ground pins on top row and power pins on bottom row, whereas EPS will have power pins on the top row and grounds on the bottom. So if trying to cram either in the wrong port, you'll be putting 12v into the ground, and running power in the back door to the cpu or gpu. At which point you had better pray you bought a very good psu with every level of protection and those protections are sensitive enough to actually work and save your equipment.

The reason to Never use old cables is simply that you have absolutely no idea which connection is which at the psu. That port could have power pins on one side, and grounds on the other, power in center pins and grounds outside or up/down, so tracing the wires physically, the other end will not have power at its correct pins. Damages ensue.

So you plug your pcie wire into the port that says pcie. EPS/CPU wire goes into EPS/CPU. What you end up with is exactly no different than the old fashioned psus with full solid cables. The only difference between those and a modular psu is the ability to unplug unnecessary wires.

Think about a simple 4pin molex connector. Red-black-black-yellow. That's at the connector, every molex is like that. At the psu it could be black-red-yellow-black and the wires will cross in the middle to be the correct orientation at the molex. If you use old cables from a different psu, that connection could have flat cables, r-b-b-y, so your psu puts 5v to red, black is ground and yellow is 12v. With the old cables what you'd get is red ground, black 5v, black 12v, yellow ground, the wires not physically connecting to the correct pins regardless of color. Same applies to every connection at the psu, the wires need to be physically located at the correct pins.

Ah that was the answer i was after! Thanks!

 

[juoza]

Y

So you want to downgrade from CS750M to CX750M? It's not a good move.

On the CS750M you can use both 8 pin sockets fot PCI-e and CPU because the pinout (on which pin the PSU is connected internally. 3,3v, 5v, 12v, 5vsb, ground, sense. PCI-e and CPU use 12v and ground only)) and the shape of the pins is the same. (same for any Corsair since 2014) But CS750M can be 8+ years old and the quality is not that good. Better replace it for a more decent PSU. RM850x is very good.

Yeah i just bought the rm850x.

 

[juoza]

6+2 and 4+4 matter only on the MoBo/GPU side, since on the PSU side, both cables have the same connector that goes into PSU.

Karadjgne above also explains it quite well. But here's another round of explanation;

PSU side ----------cable---------> port at the end

8 pin port -------------------------> 6+2 pin PCIE = fits only GPU
8 pin port -------------------------> 4+4 pin EPS = fits only MoBo to power CPU

Yep makes sense, thanks a bunch man. i might post a photo before i install just to verify when i get it. but i think i understand now.

One silly last question. i have a corsair hx850w from i think 2009. Professional series. really solid psu. do u think it would not last long on the 3070 ti? been using it ever since

 

[Karadjgne]

The HX were Tanks! Seriously solid and one of the best built psus of that Era, still are.

Your problem here is the capacitors. They age like a florescent lightbulb, exactly the same in fact. If you've ever seen a 4ft bulb with an end turning purple, that's where the cathode has started to build up scar deposits from the constant stream of electrons hitting it like tiny meteors. The inside of the capacitor is affected the same way. You get a breakdown in the ability of the capacitor to effectively pass full current.

That 850w will have been 850w when it was new, but after 13 years of use, it's now closer to 650w. Still good for lower wattage stuff, but anything that can demand 650w + is at high risk of either tripping the protections with a good high spike or simply overloading the caps and causing cascade failures.

Depending on the loads it saw, can change that wattage, it could be 550w if heavily abused or could be 750w if barely used, there's no exact measurement. You could use it with the Ti and get several more years worry free, or it could die the first hard load it sees. Absolutely no guarantee at that age, of anything other than now questionable reliability at high draw loads.

 

[Aeacus]

One silly last question. i have a corsair hx850w from i think 2009. Professional series. really solid psu. do u think it would not last long on the 3070 ti? been using it ever since

Again, Karadjgne explained it in detail. But i also agree, where while HX is ia good PSU, it's age is something to be concerned about. Better to go with new PSU, than use 13 year old unit.

 

[juoza]

The HX were Tanks! Seriously solid and one of the best built psus of that Era, still are.

Your problem here is the capacitors. They age like a florescent lightbulb, exactly the same in fact. If you've ever seen a 4ft bulb with an end turning purple, that's where the cathode has started to build up scar deposits from the constant stream of electrons hitting it like tiny meteors. The inside of the capacitor is affected the same way. You get a breakdown in the ability of the capacitor to effectively pass full current.

That 850w will have been 850w when it was new, but after 13 years of use, it's now closer to 650w. Still good for lower wattage stuff, but anything that can demand 650w + is at high risk of either tripping the protections with a good high spike or simply overloading the caps and causing cascade failures.

Depending on the loads it saw, can change that wattage, it could be 550w if heavily abused or could be 750w if barely used, there's no exact measurement. You could use it with the Ti and get several more years worry free, or it could die the first hard load it sees. Absolutely no guarantee at that age, of anything other than now questionable reliability at high draw loads.

Thanks for the really detailed response, much appreciated!

 

[juoza]

I just got my psu and barely got it to fit in my case haha, but ended up being ok once I reallocated the hdd tray. Just want to confirm if this setup is correct? 2 seperate pcie cables in those 2 seperate slots and the cpu cable next to it. I didn't utilize the top pcie /cpu slot originally cause not enough room between hdd cage and psu cable.https://ibb.co/vx7XK23

 

[Aeacus]

Just want to confirm if this setup is correct?

Yes.

Though, it doesn't matter which ports on PSU side, you use for GPU and which for CPU.

E.g below is my PSU's connectors:

Upper image - connectors
Lower image - end result (do note that i have my PSU flipped upside down, for fan to be at the bottom)