Sata to 8 pin connectors

[LTD3000]

I have finally gotten VR in to the college and with that, we will be getting some GTX 1080's to install on some of our Dell xeon systems.

Although the PSU's are Stock manufacture dell PSU's and do not have 8 pin connectors on them,

but it dose have one free sata power cable free for use.

 

so my question is, if I get a sata splitter to give me 2 sata power connectors and then plug them in to a 2 sata to 8 pin connectors, will that work or is that likely to cause problems?

 

and just to add I am not a 100% on wattage of the PSU but will be able to find that out on Friday.

This is my firs post so hope I did everything right 

[blu4]

It's not going to work because the power draw will exceed the rail voltage on the PSU. You will more likely get away with molex connectors but just use the proper ones. Don't risk damaging something.

[Naeaes]

Whooooooo. Nooooooo.  Don't do it man! The 12VDC rail on Sata is rated for 45W whereas the 8-pin connector is rated for 150W. The GPU has no idea there's an adapter in there and that it's not cool to draw more than 45W. It'll destroy the PSU. Really, actually, blow it up. Do not even try!

[Naeaes]

3 minutes ago, blu4 said:

It's not going to work because the power draw will exceed the rail voltage on the PSU. You will more likely get away with molex connectors but just use the proper ones. Don't risk damaging something.

NO! Molex is rated for 45 Watts on the +12VDC side. the 150W draw will destroy that too.

[blu4]

Just now, Naeaes said:

NO! Molex is rated for 45 Watts on the +12VDC side. the 150W draw will destroy that too.

Well... I got molex to 8pin with my 980ti

[Naeaes]

2 minutes ago, blu4 said:

Well... I got molex to 8pin with my 980ti

Good for you! Don't let your warranty provider hear that.

"Rated for" doesn't mean that there's an actual detonation device in there that's triggered by a current monitor. At times, you can get lucky and exceed the specs. The manufacturers do have the option to put in chunkier wiring if their margins allow. The thing is, OP has an OEM PSU. It's not going to be like your Corsair PSU.

[LTD3000]

Hmmm this is very interesting, I never realized that there was a watt limit on each rail.

My dad actually uses a 2 Sata to 8 pin connector so will tell him to buy a proper PSU.

Thanks for the comments this has already helped a lot!

If I get another PSU are there any recommendations, after this upgrade it is very unlikely the systems will get another upgrade so bare minimum is ok.

[Cryptonite]

1 hour ago, LTD3000 said:

Hmmm this is very interesting, I never realized that there was a watt limit on each rail.

My dad actually uses a 2 Sata to 8 pin connector so will tell him to buy a proper PSU.

Thanks for the comments this has already helped a lot!

If I get another PSU are there any recommendations, after this upgrade it is very unlikely the systems will get another upgrade so bare minimum is ok.

it depends though, some PSUs use a single powerful rail and are not split, however split rails are the most common.

[LTD3000]

19 minutes ago, Cryptonite said:

it depends though, some PSUs use a single powerful rail and are not split, however split rails are the most common.

Ok so if it's a single rail then the wattage may be high enough, ok makes sense thanks Cryptonite.

[Edgar R. Zakarian]

6 hours ago, Naeaes said:

NO! Molex is rated for 45 Watts on the +12VDC side. the 150W draw will destroy that too.

Wait what?

 

There are adapters going from 2xmolex ->6-pin Pci-e or even 8-pin pci-e.

 

Will all these destroy all the power supplies they are used on then?

 

[Cryptonite]

4 minutes ago, Edgar R. Zakarian said:

Wait what?

 

There are adapters going from 2xmolex ->6-pin Pci-e or even 8-pin pci-e.

 

Will all these destroy all the power supplies they are used on then?

 

no. it depends on each individual psu. you get single rail PSUs that spreads the wattage across all connectors. You even get some PSUs that are say split into rails like one of mine: 140w, 240w and 216w however the maximum load of them all together cannot exceed 535 watt. so mine wouldn't mind a Molex to 6/8 pin connector (second pc)

[Edgar R. Zakarian]

1 minute ago, Cryptonite said:

no. it depends on each individual psu. you get single rail PSUs that spreads the wattage across all connectors. You even get some PSUs that are say split into rails like one of mine: 140w, 240w and 216w however the maximum load of them all together cannot exceed 535 watt. so mine wouldn't mind a Molex to 6/8 pin connector (second pc)

How do you even check the rails on a PSU? Haven't seen anything,

YOu have to find the datasheet or? Is it always IN the datasheet?

[Cryptonite]

8 minutes ago, Edgar R. Zakarian said:

How do you even check the rails on a PSU? Haven't seen anything,

YOu have to find the datasheet or? Is it always IN the datasheet?

depends from brand to brand, some of them even have a column on the PSU showing the rail wattages.

[mariushm]

25 minutes ago, Edgar R. Zakarian said:

Wait what?

 

There are adapters going from 2xmolex ->6-pin Pci-e or even 8-pin pci-e.

 

Will all these destroy all the power supplies they are used on then?

 

 

A molex connector isn't restricted to a particular amount of current. The value of 45w is more or less a recommendation, devices that are to be powered from a molex connector should be designed in such a way as to not consume more power than that value.

 

The maximum current that can go to a device is limited by the diameter of the wire first of all ... for AWG18 wires (the most often used in PC power supplies), the maximum recommended is about 8-10A in order to prevent the cables from heating and reduce the voltage drop on the cable due to internal wire resistance. There's also the issue of mating of connectors - there's often resistance at the contact, imperfect connections / oxidation / etc can cause electric arcs or overheating of the metal contacts/pins and potentially damage the connector if the current is too high.

That's why the molex recommends to be maximum 45w ( 12v @ 3-4A or something like that, same for 5v), because power supplies could have a strip of 2-3 molex connectors and in total the strip could provide to 3 devices up to maximum safe current for that single yellow wire (3-4A per connector, times 3 connectors in the strip)

 

Safety, reliability..  and Voltage drop are reasons there's more than a single pair of wire going to a pci-e connector ..

 

A 6 pin pci-e connector is meant to provide the video card with 75w ( 12v at about 6A) through three pairs of wires, but even a single pair of wires could actually provide those 75w safely. But, at 6a going through a single pair of wires you may have 12v at the power supply but the video card only sees 11.8 or 11.9v at the connector due to the voltage drop on the cable (caused by the resistance of the wire itself). By going with 3 pairs of wires, the current is even through each pair and the voltage drop is smaller, and in addition everything is also safer because if one of the contacts is loose or bad, there's still two other pairs capable of providing the full power the video card needs.

 

[Naeaes]

7 hours ago, Edgar R. Zakarian said:

Wait what?

 

There are adapters going from 2xmolex ->6-pin Pci-e or even 8-pin pci-e.

 

Will all these destroy all the power supplies they are used on then?

 

"Only a Sith deals in absolutes." The thing is, if a wire is rated for 45W, it can still handle more if it's made "too thick". Some powersupplies have overcurrent protection that actually works and prevents catastrohies and so on. But waht the power supplies don't have is individual fuses for the internal DC rails.

So pretty much, yeah. As you probably know, higher wattage needs thicker cables so the cables for a 45W line can be pretty flimsy in comparison to 150W line cables. Things like the connectors and solder joints tend to be most at risk. You know the trick with a single strand from a wire and a 9V battery? If you connect the strand to the leads, it gets hot enough to melt plastics and styrofoam. Until it burns out or burns your fingers. It's the same effect. Too much current though the too thin wire makes it heat up, melt the plastic insulation, the cores contact each other and you got a short on your hands. Boom goes the PSU.

 

The 45W-thing and 150W-thing and other stuff I'm omitting come from the ATX12V and Intel EPS12V specifications. ATX12V v2.4 I believe is the most recent but in consumer-grade stuff I most often see compliance with v2.31. That's the one that made the 80% minimum efficiency mandatory IIRC. 

 

Edit: Oh, yeah, the adapters. They exist. That's right. And super scary. I guess there's no law against connecting a plug to another with a few wires. And even if there was, who's going to keep morons from daisy-chaining the adapters. The 2x Molex to 6-pin is actually technically fine since one Molex is 45W and the 6-pin PCI-E is 75W. But the thing is, the Molex connectors on the PSU usually stem from a single wire. It just moves the weak point to the PSU wires instead of the adapter. 

 

BTW, these specs are the reason the 6+2-pin PCI-E connectors exists. The specification says there has to be 8-pins (but nothing about how many wires) for the 150W line. So they just build the 6-pin cables with enough gauge for 150W and split the extra two wires at the very end.

[don_svetlio]

14 hours ago, LTD3000 said:

I have finally gotten VR in to the college and with that, we will be getting some GTX 1080's to install on some of our Dell xeon systems.

Although the PSU's are Stock manufacture dell PSU's and do not have 8 pin connectors on them,

but it dose have one free sata power cable free for use.

 

so my question is, if I get a sata splitter to give me 2 sata power connectors and then plug them in to a 2 sata to 8 pin connectors, will that work or is that likely to cause problems?

 

and just to add I am not a 100% on wattage of the PSU but will be able to find that out on Friday.

This is my firs post so hope I did everything right 

The chances of you starting a fire are high - very high

[LTD3000]

Ok thanks everyone for your input!

I have decided to buy some new PSU's