Not enough 6pin on PSU - Woops

Zico

Zico

Zico

Soldato
Joined
15 Jan 2003
Posts
4,947
Location
South East
I bought a OcUK Crusade 850W PSU a month or so back but miss-read the spec.

I am fitting my PC with 2x 5850 gfx cards which both need 2x 6pin pcie power connections.

The PSU only has 2x 6pin pcie connections which means I am 2x short :(.

The PSU has 4 other cables as follows:
2x 4pin molex (one cable has 3x molex plugs, the other has 2x molex)
2x sata (both cables have 3x sata plugs).

Could I use each of the molex cables (using 2x plugs on each cable) with the following molex to 6pin pcie adaptor or do I need to use two seperate molex cables with a single adaptor (4x molex cables each connected to an adaptor)?


I plan on using the 2x sata power cables to power my DVDR (1 cable) and 2x HDD (1 cable).
 
Last edited:
I've just checked and I have molex to 6pin adaptors.

The XFX quick install guide does not support the use of molex to 6pin. It also shows the use of 2 seperate molex cables connecting to the adaptor.

Do I need to use two seperate molex cables running from the psu or can I use a single cable and connect to two plugs?

**edit**
Not that it makes much difference but the actual 5850's in question are Asus reference cards. The XFX quick install guide is also from a reference card.
 
Justintime said:
Would use seperate lines.
Click to expand...

Chuffing thought so!!

If that is the case then I am still screwed as I only have two seperate molex cables running from the psu.

I could possibly supplement using the two molex lines + adaptor and then the two sata lines with an adaptor but I would also be running the 2x hdd and 1x dvdr off of the sata lines.

Looking likely that I will need to get another psu :(
 
Justintime said:
Hmm.. a little bit of digging around points to it being a powercool rebranded unit.. Personally i'd not use it if it was.
Click to expand...

Yup, PowerCool 850W.

I'm most likely going to order a new PSU but I am wondering if it is worth me shipping this one back to OcUK for some kind of partial store credit (£60 - shipping plus whatever re-stocking fee they charge).
 
Zico said:
I'm most likely going to order a new PSU but I am wondering if it is worth me shipping this one back to OcUK for some kind of partial store credit (£60 - shipping plus whatever re-stocking fee they charge).
Click to expand...
Hate to say this, but I doubt OcUK will take that PSU back since it was bought a month ago (especially something that's basically a 2nd hand generic PSU). If it was still within the DSR period, then it's different...but unfortunately it's not.

Be wise next time...there's no shame in asking for advise prior to buying hardware. I seriously won't run a pair of 5850 in crossfire with that PSU...the 12v rail most likely won't handle the load and make the PSU go bang. Whether or not it will take the rest of your system with it, that would depend on your luck. Just get a decent reliable PSU...around 700-850W would be good, and that would be the smartest thing to do at this point.
 
Last edited:
Marine-RX179 said:
Hate to say this, but I doubt OcUK will take that PSU back since it was bought a month ago (especially something that's basically a 2nd hand generic PSU). If it was still within the DSR period, then it's different...but unfortunately it's not.

Be wise next time...there's no shame in asking for advise prior to buying hardware. I seriously won't run a pair of 5850 in crossfire with that PSU...the 12v rail most likely won't handle the load and make the PSU go bang. Whether or not it will take the rest of your system with it, that would depend on your luck. Just get a decent reliable PSU...around 700-850W would be good, and that would be the smartest thing to do at this point.
Click to expand...

The stupid thing is that I only took the thing out of the box a week ago and it was while I fitted it into the case yesterday that I noticed the error (been too busy at work to build anything until now).

To top things off, I must have been having a blonde moment when I ordered the psu as my other two systems (built 2 yr's ago) both have Corsair TX 650/950 PSUs respectively.

I've raised a ticket to query if OcUK will accept the Crusade PSU back (no harm in asking) and I'm now looking at either of the following PSUs:

Lepa B 850W
Antec 900W
 
Zico said:
I'm now looking at either of the following PSUs:

Lepa B 850W
Antec 900W
Click to expand...
The Antec High Current Gamer 900W would be the better out of the two, as it can output 850W on the 12v rail, and has a longer warranty period of 5 years comparing to 2 years offered by Lepa B.

While there are not a lot of user feedback for the Antec High Current Gamer series, the 750W model got a very good review on Custom PC (bit-tech) and they gave it premium grade rating, so I would imagine the same high quality applies to the 900W model as well. To be honest, I think a decent brand 750W would do you fine...but looking at the prices and seeing that the 750W PSUs are not much cheaper than the Antec High Current Gamer 900W, it is probably a good idea to go for the Antec High Current Gamer 900W for more headroom, which will allow the PSU to run more efficiently as well as more headroom for future upgrade. Just to give you an idea...each PCI-E 6pin will out put a max of 75W, so for a 2x6pin card, it will consume a max of 225W (75Wx2+75W from the PCI-E x16 slot). So basically power wise it would take three 2x6pin cards (total 675W), and still have 175W left for the CPU and other things that run on the 12v rail. But physically, it has four 6+2pin, so it's more toward two high power consumption cards rather than 3 moderate power consumption cards...but if you add two more PCI-E 6pin adapter, tri-fire 5850 or 6950 is doable.
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom