CX750M Safe to use?

[JamiePCMR]

Is this safe/correct should i upgrade PSU?
Im using a single PCIE cable from the PSU and then using the 2x 6+2pin splitter that comes off it for my 1080ti (Needs 2x 8 pin). PSU is the Corsair CX750M (Grey 2017 Version)

Full spec below.

Case - Corsair iCUE 465X RGB Mid-Tower 
CPU - Intel core I5-9600K 3.7GHz/4.6GHz 
Motherboard - ASUS ROG Strix Intel Z390-E GAMING 
Ram - Corsair Vengeance LPX 16GB 3200MHz 
GPU - ASUS ROG Strix GeForce GTX 1080 Ti OC Edition 11GB
Power Supply - Corsair CX750M Semi Modular 
SSD - Samsung 860 Evo 500GB 
HDD - 1TB WD 7200 / 1TB Samsung 7200
Cooler - Corsair Hydro H100i RGB Platinum 240mm 
Fans - 3x ML120 / 2x ML120 Pro Rgb 
Cables - Custom Sleeved 

Thanks for your time

[Kanna]

Why wouldn't it be safe?

[BlueChinchillaEatingDorito]

Seems like a Tier B supply on our PSU Tier list. You should be fine.

 

[JamiePCMR]

3 minutes ago, Kanna said:

Why wouldn't it be safe?

Using a single cable? Ive read you should avoid this but why would they include a splitter? Just want reinsurance from PCMR Pros

[Kanna]

Just now, JamiePCMR said:

Using a single cable? Ive read you should avoid this but why would they include a splitter? Just want reinsurance from PCMR Pros

Can I get an image of the splitter?

[JamiePCMR]

2 minutes ago, BlueChinchillaEatingDorito said:

Seems like a Tier B supply on our PSU Tier list. You should be fine.

 

Awesome glad to know! Thanks

[BlueChinchillaEatingDorito]

3 minutes ago, JamiePCMR said:

Using a single cable? Ive read you should avoid this but why would they include a splitter? Just want reinsurance from PCMR Pros

Wait, what sort of cable is this again? Is this something that came with the GPU? I'm sort of confused as to what this cable you're describing is. 

[TechJezus]

Just now, JamiePCMR said:

Using a single cable? Ive read you should avoid this but why would they include a splitter? Just want reinsurance from PCMR Pros

It's safe. But the 1080ti needs more power then a single cable can deliver to reach maximum boost clock. 

[JamiePCMR]

PCIE cable for the GPU

[JamiePCMR]

1 minute ago, TechJezus said:

It's safe. But the 1080ti needs more power then a single cable can deliver to reach maximum boost clock. 

Right now i know why 2 individual cables are better thanks! Also could using a single cable cause more coil whine? 

[JamiePCMR]

5 minutes ago, Kanna said:

Can I get an image of the splitter?

[JamiePCMR]

5 minutes ago, BlueChinchillaEatingDorito said:

Wait, what sort of cable is this again? Is this something that came with the GPU? I'm sort of confused as to what this cable you're describing is. 

[Kanna]

Just now, JamiePCMR said:

Yeah that is just a normal PSU cable it's fine

[JamiePCMR]

Just now, Kanna said:

Yeah that is just a normal PSU cable it's fine

Ok great stuff thanks

[Spotty]

8 minutes ago, TechJezus said:

It's safe. But the 1080ti needs more power then a single cable can deliver to reach maximum boost clock. 

The graphics card will draw however much power it needs, regardless of whether there's two cables plugged in to the PSU side or just one. There won't be any difference in the max boost clock.

[TechJezus]

Just now, Spotty said:

The graphics card will draw however much power it needs, regardless of whether there's two cables plugged in to the PSU side or just one. There won't be any difference in the max boost clock.

No, that is just wrong. one single cable could only deliver 150w. That gives you 225w to the gpu, from one cable and the motherboard. The 1080 ti is a 250w card at stock. Why do you think cards come with more than one pcie power connector, if one cable is all you need? 

[SansVarnic]

13 minutes ago, TechJezus said:

No, that is just wrong. one single cable could only deliver 150w. That gives you 225w to the gpu, from one cable and the motherboard. The 1080 ti is a 250w card at stock. Why do you think cards come with more than one pcie power connector, if one cable is all you need? 

The cable doesn't determine draw. The GPU determines draw and PSU rail will provide what the GPU wants unless the rail is limited by its step downs and resistors. (PSUers don't nit pick me I am just speaking basics). The real issue is whether or not the cable can handle the load safely. Copper gauges are rated for loads, yes, but do not determine the load it carries.

 

I can always run a 1200 watts at 100 amps on a 12 gauge wire and yes it will burn but it will still carry the load until it burns.

[Spotty]

5 minutes ago, TechJezus said:

No, that is just wrong. one single cable could only deliver 150w. That gives you 225w to the gpu, from one cable and the motherboard. The 1080 ti is a 250w card at stock. Why do you think cards come with more than one pcie power connector, if one cable is all you need? 

I think you might be confusing cable with connector.

OPs power supply comes with a cable that has two PCIe connectors on the end. You can see the photo in their post above. Single cable with two connectors can occupy both 8pin PCIe slots on the graphics card.

Their cx750m should come with two PCIe cables with 2 connectors on each cable, for a total of 4 6+2pin PCIe connectors. Assuming they haven't lost the cables if they want to they can use both cables with one connector from each cable and the second connector on each cable will just dangle loose in the case.

 

Power cables are kind of dumb. They don't really know how much power is going through them and they don't limit themselves to 150w. That's just what is recommended for an 8pin PCIe cable. The cable will deliver whatever the card pulls. If it's too much, eventually the cables or connector will melt or burn. That's why it's common to see melted SATA connectors when someone uses a SATA to PCIe adapter to power a graphics card.

Fun fact: the 6pin PCIe cable and 8pin PCIe cable have the same number of 12v wires (3), even though the 6pin is only recommended for 75w. 

Der8auer has a video where he cuts wires from the PCIe cable to see if it'll still work, I'll recommend giving it a watch as it might surprise you. He also explains the PCIe connector in a bit more depth.

[SansVarnic]

9 minutes ago, Spotty said:

<snip>

[Guest]

Absolute maximum capability of that cable is 336W.

 

But as current rises, temperature of the pins rise.  As current and temperatures rise, voltage drops.

 

So while it should be "safe", be aware of the potential problems you may encounter.