Not enough 6pin on PSU - Woops

Zico · 25 Dec 2011 at 02:41

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).

Zico · 25 Dec 2011 at 02:57

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.

Zico · 25 Dec 2011 at 03:05

Justintime said:
Would use seperate lines.

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

Zico · 25 Dec 2011 at 03:45

jmc007 said:
Forget crossfire and get a new single card solution?

The 5850s are being recycled (free) and I am not looking to replace them with a single card solution unless it is also free.

KingArthur said:
THROW THAT PSU IN THE BIN NOW BEFORE IT EXPLODES IN YOUR FACE!

Thank you for your useful comment. :rolleyes:

Zico · 25 Dec 2011 at 04:05

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.

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 · 25 Dec 2011 at 04:56

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.

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