PCIe riser and GPU on single 6-Pin line?

Vann

hero member

Activity: 1036

Merit: 606

Quote from: thedon84 on June 26, 2017, 05:33:07 PM

Whoops, forgot about the 3rd pin, my fault. Roll Eyes

The Y-cable of Amazon probably does not fit for PCIe (reviews)

Quote from: Vann on June 26, 2017, 03:40:48 PM

Powered risers draw less than 50 W and are perfectly safe to use with a SATA connector.

How do you know that a riser needs less than 50W? I've nowhere found infos about that.

If you have a power usage meter and a dual PSU setup like I do that has the main PSU powering the motherboard and all of the risers and the second PSU powering the VGA power inputs, you will find each of the risers use 45-50 W.

https://bitcointalksearch.org/topic/m.19780697

BBT also uses molex and SATA powered risers for his builds and has said the same. The cable in the link should work for the 6+2 cables coming from a PSU PCI-E port. If you want a better quality one with thicker cables there is this one.

http://www.ebay.com/itm/11-Inch-18AWG-PCI-Express-PCIE-8-Pin-Male-to-2x-PCI-E-6-2-Female-Splitter-Cable-/322543875241

hyet24

full member

Activity: 166

Merit: 100

He is right I had all the main PSU powering the PCIe while server PSU power the 2 GPUs. I notice the main PSU still draws under 400w even though it is powering the all the PCIe risers.

My setup is this
single 1080ti and all 4 PCIe risers on main that consume around 350w it should have been around 600w if those risers are doing highload work.
three 1080ti on the server PSU and the consumption peak around 700w.

another thing i found out if you don't connect the PCIe risers to server PSU. its easy to turn on both PSU without timing. you can turn on the server PSU first before main PSU. this leaves me thinking that the PCIe risers all it does power GPUs to connect and recognize while the PCIe 6 pin and 8 pin on the GPU gets use while on the load.

thedon84

newbie

Activity: 10

Merit: 0

Whoops, forgot about the 3rd pin, my fault. Roll Eyes

The Y-cable of Amazon probably does not fit for PCIe (reviews)

Quote from: Vann on June 26, 2017, 03:40:48 PM

Powered risers draw less than 50 W and are perfectly safe to use with a SATA connector.

How do you know that a riser needs less than 50W? I've nowhere found infos about that.

Vann

hero member

Activity: 1036

Merit: 606

Quote from: thedon84 on June 26, 2017, 03:06:06 PM

@rogeriosmorais:
Sata Power only got two 12V lines, each for 1.5A = 36W total
4-Pin Molex are 5A on 12V = 60W
PCIe x16 is specified for 75W and you can find pictures of burnt sata and molex plugs which were used for risers

Sata connectors have 3 12V pins for a total of 54 W. The SATA cable and connector are rated to handle 4.5A over each of the 3.3V, 5V and 12V rails for a total of 91.35 W.

http://www.playtool.com/pages/psuconnectors/connectors.html#sata

Powered risers draw less than 50 W and are perfectly safe to use with a SATA connector. Burnt connectors are from overloading the cable by using more than two connectors per cable strand MAX or using a Sata connector to power a high draw card.

You can use an 8-pin splitter cable into dual 6 pins to power the card and riser on the same cable.

https://www.amazon.com/Phobya-PCI-E-Splitter-Cable-Sleeving/dp/B00A5TA7NG

thedon84

newbie

Activity: 10

Merit: 0

@rogeriosmorais:
Sata Power only got two 12V lines, each for 1.5A = 36W total
4-Pin Molex are 5A on 12V = 60W
PCIe x16 is specified for 75W and you can find pictures of burnt sata and molex plugs which were used for risers

rogeriosmorais

newbie

Activity: 26

Merit: 0

Can't you use molex or SATA for the riser? What you intend to do doesn't sound like a good idea.

thedon84

newbie

Activity: 10

Merit: 0

Hi,
as far as i know the 6-Pin PCIe can handle up to 75W, while the 8-Pin can handle 150W.
could it be a problem if I connect a GPU (6-Pin) and a PCIe riser (6-Pin) with an Y-Cable together on a single PCIE 6-Pin line? (cant find Y-Cable with 8-Pin input Roll Eyes

)

http://fs5.directupload.net/images/170626/q78qzhev.jpg

http://fs5.directupload.net/images/170626/cxby5dq3.jpg

Topic: PCIe riser and GPU on single 6-Pin line? (Read 824 times)