Seasonic X Series 850w and LGA 1366

[gun5l1ng3r]

Recently I have thought about adding another GTX 780 to my system.

I thought a 850w from Seasonic (X series, gold) would have the required connections...but I think my LGA 1366 x58 setup prevents this.

The PSU has 2 connectors on the back for PCI-e. One is needed to connect to my mother board and the other is used for my current 780.

Am I missing somthing here? Does the LGA 1366 take so much power that I have to sacrifice a PCI-e connection? It seems the only way to add another card is to use molex to PCI-e connectors off the peripheral rail...

Model number of the PSU X-850 SS-850KM.

I ended up getting their 1000W platinum and it looks like I will have 3 PCIe connections which allows me to conncet the LGA 1366 power plug and 2 GPU's


EDIT: Google Image search and you will see the layout for the back of the PSU. The connector labeled "CPU" did not fit with the cable provided to attach to the mother board. The only cable that I have that fits requires on of the wider PCIe slots

 

[lehtv]

What board?

 

[gun5l1ng3r]

It is a EVGA X58 SLI LE

Link to board manual Support Manual for EVGA X58 LE (141-BL-E757)

 

[lehtv]

OK. I'm not quite sure awhat you mean by this:

The PSU has 2 connectors on the back for PCI-e. One is needed to connect to my mother board and the other is used for my current 780.

The board does not need PCIe power. Never heard of a board that does. All it needs is 8-pin (EPS) for the CPU and standard 24-pin for the main power.

 

[gun5l1ng3r]

OK. I'm not quite sure awhat you mean by this:



The board does not need PCIe power. Never heard of a board that does. All it needs is 8-pin (EPS) for the CPU and standard 24-pin for the main power.

The PSU side for the 8 pin power EPS connects to the PSU in place of one of the PCIe sockets, leaving me only one open PCIe power connection.

Basically the cable that goes from my 8 pin EPS is more like 10 or 12 pins on the PSU side of the cable and needs to plug into one of the 2 available PCIe slots leaving no room for SLI

 

[lehtv]

It can't be that limited. Even my X650 and my current X660 can connect four PCIe connectors simultaneously with an EPS connector. Let's look at the X850 layout...

So there you have a 4x2 connector for the CPU, and two 6x2 connectors covering all four PCIe cables.

It seems to me you've been plugging the CPU cable into the PCIe/CPU header, leaving the CPU-only header unused.

 

[gun5l1ng3r]

It can't be that limited. Even my X650 and my current X660 can connect four PCIe connectors simultaneously with an EPS connector. Let's look at the X850 layout...

So there you have a 4x2 connector for the CPU, and two 6x2 connectors covering all four PCIe cables.

It seems to me you've been plugging the CPU cable into the PCIe/CPU header, leaving the CPU-only header unused.

I tried plugging the CPU only header into the 8pin but the cable will not connect to the M/B, thus I have to use the cable that has a 2x5 on the PSU side and the 8 pin EPS on the M/B side.

Maybe I need to look in my Seasonic bag for a different cable.

I was just wondering if all the of LGA platforms used the secondary 8 pin EPS and maybe LGA 1366 used an extra connector, thus reducing the number of PCIe plugs I have.

In the end, would a 850w be enough for 2 overclocked 780's and an overclocked (3.6ghz) i7 920?

 

[BTRY B 529th FA BN]

My EVGA 760 A1 has 2 8pin motherboard connections. Both aren't necessary, but I think 1 is. The manual should tell you.

 

[theAnimal]

The board does not need PCIe power. Never heard of a board that does.

The EVGA SR-2 mobo has 2 PCIe connectors (1 per CPU) for OCing purposes (but not required).