[Smeghead_3]

Ok, RickRuski thank you for taking the time to help.
Your suggestion of using precision has lead to a few discoveries.

I monitored both GPU's whilst running COD and both were at 99%, but no SLI indicator was present. I thought great it's working but the SLI overlay isn't showing up.
I tried a few other games that work well with SLI and discovered that with SLI enabled both GPU's were in the 80-85% range. But if I disabled SLI (in inspector) then both GPU's were at 99%. If i completely dissabled SLI in the control panel then GPU behaviour was as expected ie 99%, 3-5%.
It seems that setting SLI rendering mode to force single in inspector , whilst in surround mode, is not the same as disabling SLI. SLI rendering is disabled but both cards still run flat out, no idea what the second card is really doing though.

But with 2 graphic cards disabling SLI in the control panel also disables surround, must be because you have to have monitors on both cards.

Long story short, whilst testing all this out I ran COD with surround disabled and SLI worked fine.

So I can run with surround off and SLI on or nice 3 screen surround and SLI off.

Haven't had this issue with any other game but with COD development at an end it seems that it wont be fixed, unless of course you know how to enable SLI in COD whilst nvidia surround is enabled ?
I might try messing about in inspector, now that I know that the profile is definitely working

thanks again,