Asus rog mars gtx 760 sli disabled!!!

[stf61]

Hi there,
Recently I've bought a ASUS ROG MARS GTX 760 Graphics card. But sorry to say that, I can only find 2gb of vram instate of 4gb!!! I've tried to enable SLI. But there is no SLI option in NVIDIA CONTROL PANEL. Picture attached. please help me!!!! Thanks
My system configuration is:

Processor: Intel core i7-3770
Mobo: Asus p8z77-v
8GB ADATA ddr3 2000g 2oz RAM
Kingstone SV300 120GB SSD
600W power supply

[kkn]

it have shared memory, 2 gigs on each GPU chip.
http://thepcenthusiast.com/asus-mars-gtx-760-dual-gpu-review/

[stf61]

stf61 wrote:
Hi there,
Recently I've bought a ASUS ROG MARS GTX 760 Graphics card. But sorry to say that, I can only find 2gb of vram instate of 4gb!!! I've tried to enable SLI. But there is no SLI option in NVIDIA CONTROL PANEL. Picture attached. please help me!!!! Thanks
My system configuration is:

Processor: Intel core i7-3770
Mobo: Asus p8z77-v
8GB ADATA ddr3 2000g 2oz RAM
Kingstone SV300 120GB SSD
600W power supply

This is the peoples review.. here shows that their gpu is enabled SLI


But mine one said that SLI is disable... How may I able to enable SLI on this card?? TIA