Recent Prblems with Iray and Daz

sylak2_09896ed591

I dont know why but lately trying to render a scene it gets to 2% and then iteration after iteration is produced but the percentage does not change.

Also the REnder times seems to have increased exponetially I cant work it out.

The Render is really grainy quite a few times I have then left it overnight to render expecting when I look at it in the morning it will all have cleared up but no.

The render has finished but the image quality is exactly the same as when I left it very grainy.

I am using two nvidia cards a 750GTX and a 680GTX previously these same scenes has been ok I have tried adding iray lights reducing iray lights increasing luminosity on said lights but nothing seems to help.

Any ideas on what I need to change?

 Cheers

Sy