Does a 8 pin to 2x 8 pin also only provide 150w max?

[deezy263]

Normaly a single 8pin to 8pin connector is said to be able to provide max 150w (or at least without getting too hot). I was just wondering if a 8 pin to 2x 8 pin is also only able to provide 150w at max? I have a be quiet Pure Power 11 700w PSU which includes 12pin (from which only 8 are used) to dual 8pin connectors for the GPU. 

[WhitetailAni]

1 minute ago, deezy263 said:

Normaly a single 8pin to 8pin connector is said to be able to provide max 150w (or at least without getting too hot). I was just wondering if a 8 pin to 2x 8 pin is also only able to provide 150w at max? I have a be quiet Pure Power 11 700w PSU which includes 12pin (from which only 8 are used) to dual 8pin connectors for the GPU. 

Yep. It will still just provide 150W.

You're just splitting up the power delivery pins, which isn't recommended.

 

[deezy263]

8 minutes ago, ragnarok0273 said:

Yep. It will still just provide 150W.

You're just splitting up the power delivery pins, which isn't recommended.

 

Well atm I'm using a Gigabyte Vega 56 Gaming OC which can consume under heavy load up to 280W I think, which also is only plugged into one of those cables. Sometimes I had some black screen issues with a 100% fan speed. Never thought that this cable might be an issue until i randomly read, that a 8 pin is only supposed to provide 150w max. Do you think that this issue might be because of the cables? And also I found some cables from be quiet which are using the full 12 pin connector on PSU side to a dual 8 pin on GPU side, do you think that this cable will do it, if the cable might be a problem? Of course I could also just plug in separat 8 pin, but I'm planning on getting a RTX 3080 if I can get one for around MSRP and these use (with aftermarket cooler) 3x pin connectors. So I'm also wondering if I upgrade, do I have to upgrade my PSU as well, as I can only plug in 2 PCIE cables in my PSU?

[WhitetailAni]

Just now, deezy263 said:

Well atm I'm using a Gigabyte Vega 56 Gaming OC which can consume under heavy load up to 280W I think, which also is only plugged into one of those cables. Sometimes I had some black screen issues with a 100% fan speed. Never thought that this cable might be an issue until i randomly read, that a 8 pin is only supposed to provide 150w max. Do you think that this issue might be because of the cables? And also I found some cables from be quiet which are using the full 12 pin connector on PSU side to a dual 8 pin on GPU side, do you think that this cable will do it, if the cable might be a problem? Of course I could also just plug in separat 8 pin, but I'm planning on getting a RTX 3080 if I can get one for around MSRP and these use (with aftermarket cooler) 3x pin connectors. So I'm also wondering if I upgrade, do I have to upgrade my PSU as well, as I can only plug in 2 PCIE cables in my PSU?

If your PSU doesn't have the necessary cables, it's for a reason.

You'll need to upgrade your PSU.

[deezy263]

10 minutes ago, ragnarok0273 said:

If your PSU doesn't have the necessary cables, it's for a reason.

You'll need to upgrade your PSU.

But then why would the PSU provide cables with a 12 pin to dual 8 pin?

[WhitetailAni]

Just now, deezy263 said:

But then why would the PSU provide cables with a 12 pin to dual 8 pin?

Because the PSU can support 300W on PCIe power, but not 450W.

[deezy263]

3 minutes ago, ragnarok0273 said:

Because the PSU can support 300W on PCIe power, but not 450W.

In this case I should be fine, should't I? Sorry for asking so dumb. But if I'll be able to get a max of 300w on the PCIE cable on PSU side, which then provides max 150w per 8pin on GPU side, then thats plenty or not? In this case one 12 pin to dual 8 pin for my Vega 56 should be enough (max of 300w) and for a 3080 simply another 8 pin (3x150w)? Am I seeing this wrong?

[WhitetailAni]

Just now, deezy263 said:

In this case I should be fine, should't I? Sorry for asking so dumb. But if I'll be able to get a max of 300w on the PCIE cable on PSU side, which then provides max 150w per 8pin on GPU side, then thats plenty or not? In this case one 12 pin to dual 8 pin for my Vega 56 should be enough (max of 300w) and for a 3080 simply another 8 pin (3x150w)? Am I seeing this wrong?

Well, unless your PSU has 3 8-pin connectors, you'll need to upgrade it.

How many PCIe power connectors does it have?

[deezy263]

1 minute ago, ragnarok0273 said:

Well, unless your PSU has 3 8-pin connectors, you'll need to upgrade it.

How many PCIe power connectors does it have?

Well my PSU has only 2 PCIE connectors, but they are 12 pin connectors and not 8 pin

[WhitetailAni]

Just now, deezy263 said:

Well my PSU has only 2 PCIE connectors, but they are 12 pin connectors and not 8 pin

I'm a bit confused as to what you mean.

Like, the NVIDIA 12-pin connector thing?

Or a connector on your power supply?
Can you take a picture?

[deezy263]

6 minutes ago, ragnarok0273 said:

I'm a bit confused as to what you mean.

Like, the NVIDIA 12-pin connector thing?

Or a connector on your power supply?
Can you take a picture?

Yeah it's kinda strange, but the newer be quiet PSUs have 12 pin PCIE connectors. And with the PSU included, there are 2 VGA cables. Each being a 12 pin to 2x 8 pin connector but on the PSU side from the 12 pins, there are only 8 in use. If you can zoom in, the cables in the very left are the ones included. And there you can only see, that on one side there are like 5 and the other side, there are 3 connected.

[WhitetailAni]

So you end up with 4 8-pin connectors total, but only 2 cables?

[deezy263]

1 minute ago, ragnarok0273 said:

So you end up with 4 8-pin connectors total, but only 2 cables?

Yeah exactly, at least on GPU side

[deezy263]

4 minutes ago, ragnarok0273 said:

So you end up with 4 8-pin connectors total, but only 2 cables?

It's a pigtail, if I recall correctly. For better understanding as to how these cables look, there are more pictures.

[Grabhanem]

That configuration is perfectly fine. The PCIe 8-pin standard is massively underspecced - physically those connectors can take 300+W without breaking a sweat - so most manufacturers break out a single connector on the PSU end to two on the graphics card end. Having an independent cable for each 8-pin is a bit better for transient response, but not strictly necessary.

[seon123]

1 hour ago, deezy263 said:

black screen issues with a 100% fan speed.

Not a PSU issue, then. Try troubleshooting other things. 

 

As for the cables, you are supposed to use one connector from each PCIe cable for high power GPUs, over 225W. Additional, the 12V rail configuration on the Pure Power 11 is a bit strange, which is even more reason to use two separate cables for high power GPUs. PCIe 1 is shared with EPS, and PCIe 2 is shared with ATX, peripherals, and SATA. 

[deezy263]

1 hour ago, Grabhanem said:

That configuration is perfectly fine. The PCIe 8-pin standard is massively underspecced - physically those connectors can take 300+W without breaking a sweat - so most manufacturers break out a single connector on the PSU end to two on the graphics card end. Having an independent cable for each 8-pin is a bit better for transient response, but not strictly necessary.

Alright, so I'll keep my PSU for first, I mean i can always upgrade afterwards.

 

1 hour ago, seon123 said:

Not a PSU issue, then. Try troubleshooting other things. 

 

As for the cables, you are supposed to use one connector from each PCIe cable for high power GPUs, over 225W. Additional, the 12V rail configuration on the Pure Power 11 is a bit strange, which is even more reason to use two separate cables for high power GPUs. PCIe 1 is shared with EPS, and PCIe 2 is shared with ATX, peripherals, and SATA. 

Maybe it's a heat problem? The hot spot temperature is quite high, reaching up to 100-105°C under full load. Core temp is fine though, maybe need to repaste?

So for now, I connected my second separat y-splitter to my GPU, using only 1 8-pin connector each. But if I were to upgrade to a aftermarket 3080 I'll need 3 8-pin connectors, so then I'll also need to use the y-splitter in addition to a single 8-pin. 

[WhitetailAni]

3 minutes ago, deezy263 said:

so then I'll also need to use the y-splitter in addition to a single 8-pin. 

NO.

Do NOT use it.

[deezy263]

On 2/5/2021 at 6:46 PM, ragnarok0273 said:

NO.

Do NOT use it.

I found this picture, apparently it's from a PSU manufacturer, so I guess I'll be fine? Also Seasonic says, it's standard to use a daisy chained cable, even if separate ones are recommended.

 https://knowledge.seasonic.com/article/8-installation-remark-for-high-power-consumption-graphics-cards

[WhitetailAni]

2 hours ago, deezy263 said:

I found this picture, apparently it's from a PSU manufacturer, so I guess I'll be fine? Also Seasonic says, it's standard to use a daisy chained cable, even if separate ones are recommended.

 https://knowledge.seasonic.com/article/8-installation-remark-for-high-power-consumption-graphics-cards

NVIDIA recommends a 750W PSU minimum, though.

If you have crashes where your whole PC resets once you get a 3080, it's most likely your PSU.

[Ankerson]

On 2/5/2021 at 12:41 PM, deezy263 said:

Maybe it's a heat problem? The hot spot temperature is quite high, reaching up to 100-105°C under full load. Core temp is fine though, maybe need to repaste?

So for now, I connected my second separat y-splitter to my GPU, using only 1 8-pin connector each. But if I were to upgrade to a aftermarket 3080 I'll need 3 8-pin connectors, so then I'll also need to use the y-splitter in addition to a single 8-pin. 

 

Ah no, you will need a new PSU.

 

700W isn't enough for the 2X 8 Pin cards (750W min), much less the 3X 8 Pin cards, you need an 850W PSU and even that can be tight depending on the rest of the system.

 

The 3X 8 Pin 3080's pull 450W+ with the transient power spikes of 976W.

 

Here is what my 3080 FTW3 Ultra pulls, these are exact numbers from the PSU, AXI 1600. Direct hardware link from the PSU so we get true readings of what the PSU is providing by connection.

 

468W from the 3X 8 Pin alone then another 60W from the PCIe slot for a total of 528W. And that's just pushing the card, not the CPU. The CPU is pulling 84W just running background for a total of 612W draw. My normal gaming load is more than 700W. If I push the CPU and GPU I get about 800W Power draw from the PSU to the PC.

 

[Mark Kaine]

14 hours ago, deezy263 said:

I found this picture, apparently it's from a PSU manufacturer, so I guess I'll be fine? Also Seasonic says, it's standard to use a daisy chained cable, even if separate ones are recommended.

 https://knowledge.seasonic.com/article/8-installation-remark-for-high-power-consumption-graphics-cards

I am confused how you got to that conclusion, the picture clearly tells you *not* to use a daisy chained cable... 

 

Unless you have 3 pcie connectors on your card? 

[-iSynthesis]

On 2/5/2021 at 6:41 PM, deezy263 said:

Maybe it's a heat problem? The hot spot temperature is quite high, reaching up to 100-105°C under full load. Core temp is fine though, maybe need to repaste?

So for now, I connected my second separat y-splitter to my GPU, using only 1 8-pin connector each. But if I were to upgrade to a aftermarket 3080 I'll need 3 8-pin connectors, so then I'll also need to use the y-splitter in addition to a single 8-pin. 

To find out if heat is the issue try turning up your fans to 100%, this should get your hotspot temp lower. If it still crashes it's something else.

My vega is running on 1x8pin (PSU side) to 2x8pin (GPU side) without a problem since I repasted. Even overclocked shooting over 330W. 

 

Repaste, use a lot of Thermal Paste on Vegas. Start off by tightening the two screws further away from the PCIe slot FIRST, only when they are bottomed out screw in the other two till the end. This should drop your hotspot temp, which may be the reason for the crashes you're experiencing (This happened to me). 

To find out if it's the issue or the PSU try turning up your fans to 100%, this should get your hotspot temp lower.

 

I agree with the others, if you're going for a 3080 you'll want to get a new PSU.

[deezy263]

On 2/8/2021 at 7:54 AM, Ankerson said:

 

Ah no, you will need a new PSU.

 

700W isn't enough for the 2X 8 Pin cards (750W min), much less the 3X 8 Pin cards, you need an 850W PSU and even that can be tight depending on the rest of the system.

 

The 3X 8 Pin 3080's pull 450W+ with the transient power spikes of 976W.

 

Here is what my 3080 FTW3 Ultra pulls, these are exact numbers from the PSU, AXI 1600. Direct hardware link from the PSU so we get true readings of what the PSU is providing by connection.

 

468W from the 3X 8 Pin alone then another 60W from the PCIe slot for a total of 528W. And that's just pushing the card, not the CPU. The CPU is pulling 84W just running background for a total of 612W draw. My normal gaming load is more than 700W. If I push the CPU and GPU I get about 800W Power draw from the PSU to the PC.

 

Ok thats quite a lot, I mean for the 3080 the recommended PSU is a minimum of 750W. In this case with power spikes of 976W, wouldn't it crash even with a 750W/850W PSU or are the spikes so short like  >5ms? Also the 2x 8 Pin cards have a recommended PSU of 650W (at RTX 3070 and "older"), like my Vega 56 has.

 

20 hours ago, Mark Kaine said:

I am confused how you got to that conclusion, the picture clearly tells you *not* to use a daisy chained cable... 

 

Unless you have 3 pcie connectors on your card? 

Yeah we were talking about the 3080 with 3 PCIE connectors. My Vega 56 with 2 8-pin connectors is now plugged into two separat daisy chained cables, from which only 1 connector each is used. I just have been confused about what seasonic says about this.

9 hours ago, -iSynthesis said:

To find out if heat is the issue try turning up your fans to 100%, this should get your hotspot temp lower. If it still crashes it's something else.

My vega is running on 1x8pin (PSU side) to 2x8pin (GPU side) without a problem since I repasted. Even overclocked shooting over 330W. 

 

Repaste, use a lot of Thermal Paste on Vegas. Start off by tightening the two screws further away from the PCIe slot FIRST, only when they are bottomed out screw in the other two till the end. This should drop your hotspot temp, which may be the reason for the crashes you're experiencing (This happened to me). 

To find out if it's the issue or the PSU try turning up your fans to 100%, this should get your hotspot temp lower.

 

I agree with the others, if you're going for a 3080 you'll want to get a new PSU.

Alright, I might wanna try to repaste the chip. Which thermal compound did you use? I only have Arctic Mx-4 here. Do you think it will be fine with this one? Also did you keep your thermal pads?

[Mark Kaine]

9 minutes ago, deezy263 said:

talking about the 3080 with 3 PCIE connectors.

I see but then you run into a new problem as these cards aren't like ordinary cards and 3 separate pcie cables are *recommended* regardless what "Seasonic" says...