Dell (T5400) Power Supply 12 pin to 8 pin socket mod

[mesaritism]

I just wanted to upgrade my dell precision T5400 workstation and got my self in a whole lot of trouble!

Motherboard: 0RW203
PSU: GM869 or H875E-00
Psu wire Harness: YN945

I wanted to upgrade my gpu to Sapphire r9 280x dual-x. It requires 1x6(75w) pin and 1x8(150w) pin power connectors.

These are the PSU's (850W) outpouts
P1 - 24pin ATX Power
P2 - 20pin ATX Power
P3 - 12pin Power
P4 - None
P5 - 6pin Power (2x3)
P6 - 6pin Power (2x3)
3 x Sata Connectors
1 x 4pin Molex ( +1 x 4pin Floppy on the same cable)


Both 24pin and 20pin are connected to the motherboard and if I'm not mistaken the 20pin is utilized for fan power.
My problem is that there are only 2x6 pin connectors and only 1x4 pin-molex (even if I wanted to use two molex and an adapter to produce 8 pin conntector). I don't want to use a 6pin to 8 pin adapter since that equals to a lack of 75w.

There is a strange 12 pin socket that is currently connected to a sata power cable (2 sata plugs on the cable). My question is if I can (remove the sata cable and) connect on this 12 pin socket some kind of 8 pin adapter or even if I can retrofit something my self.
The wattage and amperage have to be the same as a regular 8 pin socket.

Just found the pinout. It's the P3

Thanks to Doramious for the pinout diagramm

PS: Please don't mention the ''get a new psu'' idea.

 

[GrinningB]

Sorry guys, life interfered in a big way recently and I'm playing catch up still.

The T7400 power supply fits in with no modifications at all, I just have less room between the power supply and the dvd drive internally. No problems with airflow though. I ended up using the wiring harness form the T7400 as well. It has both the 20 and 24 pin motherboard connectors needed and ample SATA, molex etc I needed for disk drives. It also comes stock with 2 6pin pci-e connectors although one of them is piggybacked off a 10 pin connector. The only change I made was to that 10 pin with piggyback. I simply pulled the connectors out and repinned to a 8-pin pci-e for my video card and was good to go.

 

[victorhooi]

Sorry guys, life interfered in a big way recently and I'm playing catch up still.

The T7400 power supply fits in with no modifications at all, I just have less room between the power supply and the dvd drive internally. No problems with airflow though. I ended up using the wiring harness form the T7400 as well. It has both the 20 and 24 pin motherboard connectors needed and ample SATA, molex etc I needed for disk drives. It also comes stock with 2 6pin pci-e connectors although one of them is piggybacked off a 10 pin connector. The only change I made was to that 10 pin with piggyback. I simply pulled the connectors out and repinned to a 8-pin pci-e for my video card and was good to go.

I'm in a similar boat - I have a Dell T5400 and looking at powering a R9 290X as well.

I'm interested in trying the same solution - buying a Dell T7400 PSU with the wiring hardness, and using that.

You mention that you re-pinned one of the 6-pin PCI-E connectors to an 8-pin - can you provide any more details on how you did that?

Thanks,
Victor

 

[Doramius]

Again, try using the following diagram to convert any one these 12V pin types to another. Just make sure you understand any changes in amperage [and even wattage] along the rails.

 

[mcoll2000]

Hi. I have stumbled into the same zone of error in having a t5400 and a graphics card requiring a 6pin and an 8pin power input.

I understand through reading this thread that the most graceful solution is to acquire a T7400 PSU and mod a cable for 8pin.

I am adept enough to purchase the T7400 but not to wire up a modded cable.

Would anyone be willing to help me out and wire up a cable for me? Will cover all costs and add some for gratis.

Much thanks in advance.

 

[Susquehannock]

Hi. I have stumbled into the same zone of error in having a t5400 and a graphics card requiring a 6pin and an 8pin power input.

I understand through reading this thread that the most graceful solution is to acquire a T7400 PSU and mod a cable for 8pin.

I am adept enough to purchase the T7400 but not to wire up a modded cable.

Would anyone be willing to help me out and wire up a cable for me? Will cover all costs and add some for gratis.

Much thanks in advance.

Looked up the specs for your PSU (t5400). 525 watt unit with three 18-amp 12-volt rails. Likely the PCIe connector has it's own rail - converts to 216 watts. Simply use a 6-pin to 8-pin adapter. As the image above shows, both connectors utilize three 12-volt wires. They are more than capable of handling the power required.

 

[mcoll2000]

Hi. I have stumbled into the same zone of error in having a t5400 and a graphics card requiring a 6pin and an 8pin power input.

I understand through reading this thread that the most graceful solution is to acquire a T7400 PSU and mod a cable for 8pin.

I am adept enough to purchase the T7400 but not to wire up a modded cable.

Would anyone be willing to help me out and wire up a cable for me? Will cover all costs and add some for gratis.

Much thanks in advance.

Looked up the specs for your PSU (t5400). 525 watt unit with three 18-amp 12-volt rails. Likely the PCIe connector has it's own rail - converts to 216 watts. Simply use a 6-pin to 8-pin adapter. As the image above shows, both connectors utilize three 12-volt wires. They are more than capable of handling the power required.

Just for the sake of clarity you made a typo on the PSU rating, it's rated at 825W with max of 875W.

I hope you are right. I have an adaptor on order.

But if you are right, and such a solution is correct, then why all the discussion above?

Humbly, I am in the dark and have no idea what to do, other than the solution proposed here, or, as you have suggested, my first hunch was to order an adaptor.

It should be here tomorrow or the day after. I'll let you know how I get on.

 

[Susquehannock]

Yes, my bad. Was looking at t3400 unit. Given your wiring, a good option for you would be a twin 6-pin to single 8-pin PCIe adapter. Many cards ship with one in the box.

Why all the discussion? At risk of starting an argument ... there are a lot of misconceptions about 6-pin vs 8-pin PCIe and wattage provided (75-w vs 150-w). Has more to do with how the PSU is set up, and power distributed, than what the wires and connectors themselves can actually handle.

By the way. I am running Dell T3500 with 525-w PSU which has three 18-amp 12-volt rails. The 6-pin to 8-pin adapter able to handle the power hungry MSI rx480 gaming X with no under voltage or bottleneck issues whatsoever. And I am not the only one running this configuration.

 

[mcoll2000]

Yes, my bad. Was looking at t3400 unit. Given your wiring, a good option for you would be a twin 6-pin to single 8-pin PCIe adapter. Many cards ship with one in the box.

Why all the discussion? At risk of starting an argument ... there are a lot of misconceptions about 6-pin vs 8-pin PCIe and wattage provided (75-w vs 150-w). Has more to do with how the PSU is set up, and power distributed, than what the wires and connectors themselves can actually handle.

By the way. I am running Dell T3500 with 525-w PSU which has three 18-amp 12-volt rails. The 6-pin to 8-pin adapter able to handle the power hungry MSI rx480 gaming X with no under voltage or bottleneck issues whatsoever. And I am not the only one running this configuration.

Thanks for sharing your knowledge.

I might -- yet again -- be the victim of my own impulsivity.

I recently took delivery of a Dell T5400 and a XFX Radeon HD 7970 Black Edition (3072 MB). The latter demanding a 6pin and an 8pin power input.

So the Dell has two 6pins and I'm waiting on an 8pin adaptor to arrive.

In the meantime I belatedly thought a check online might be a good idea.

Now I'm worrying, but, as you suggest, it might be unnecessary and it'll all go to plan. Although I've never had a build go completely to plan. Always seem to hit some snag

 

[Susquehannock]

Figuring a solution to snags is part of the fun.

Couple additions to my last post. A lot of ideas stem from when early PSU with 6-pin PCIe did only have two 12-volt wires. And back when cards were switching from 4-pin to 6-pin PCIe, many people tried using 4-pin molex to 6-pin adapters. Never a good thing trying to supply 75-watts over a single wire. In fact, there was a post here at Tom's a couple weeks back with image of burnt connector from someone who did exactly that.

 

[mcoll2000]

O dear. My commiserations to that person.

My chief worry at the moment is that I powered up the Dell with 2 6pins into the card that wanted a 6 and an 8. It powered up, but didn't post on the monitor.

And the fans revved up so loudly -- I assume in the Dell itself -- that I took a number of steps away from it, fearing it was going to take off.

 

[mcoll2000]

Well... all well so far. The 6-pin to 8pin adaptor enables the system to boot up and wotnot. And the Dell no longer roars like it's ambling to take off from an aircraft carrier.

All good. All good.

But... can't get Windows 10 to install. Needs drivers and I haven't a clue what drivers it's ambling for.

Linux installs without complaint although I'm not convinced the best graphics drivers have been inhaled.

Snag after snag after snag.

All I wanted was an affordable system to edit videos and play a few games.

Can't find a thread anywhere that discusses windows 10 installation on a dell t5400. There must be one, surely?

 

[Susquehannock]

Twin high velocity 120mm fans I believe. Good they do not do the hurricane thing anymore.

You are probably out of luck with Win10 on that system I am afraid.

[edit] - fixed link
http://www.dell.com/support/home/us/en/04/product-support/product/precision-t5400/drivers

 

[mcoll2000]

I've been using Linux for years now. Haven't played games since Soldier of Fortune came out. Would Windows 7 suffice for to be playing some more up-to-date floaty shooters and suchlike?

 

[Susquehannock]

Win7 ... that is what I am running on this re-purposed Dell rig. Most recent game I have is Doom (2016) runs great. Especially in Vulkan. Your RX9 280X should work well with it too.

 

[mcoll2000]

Thanks Susquehannock

It's going to be fun to see what the Dell can manage. I've only heard good things so far, hence the punt.

 

[william p]

I was looking at he pinout of the Dell Precision T7400 1000W PSU. It takes the same FBDIMMS dual CPU and multiple fans. The 24 pin, and 20 pin sockets are wired the same. It doesn't have the 12 pin connector that you say is for extra SATA devices. It has more GPU connectors. I think 2-6pin and 1-8pin. It's just the T5400s big brother.