\usetikzlibrary{arrows}
\begin{tikzpicture}[scale = \FigureSize,pile/.style={thick, ->, >=stealth', shorten <=2pt, shorten >=2pt}]

	% Draw fourth fine propagation  
	\fill[gray!30] (12.5,-3) -- (14,-3) -- (14,-2) -- (12.5,-2) -- (12.5,-3);
	\fill[gray!30] (13,-4) -- (14,-4) -- (14,-3) -- (13,-3) -- (13,-4);
	\fill[gray!30] (13.5,-5) -- (14,-5) -- (14,-4) -- (13.5,-4) -- (13.5,-5);

	% Draw grid
	\draw[] plot coordinates{ (0,0) (0,-5) (14,-5) };  
	\draw[] plot coordinates{ (0,1) (14,1) };
	\draw[] plot coordinates{ (0,0) (14,0) };
	\draw[] plot coordinates{ (0,-1) (14,-1) };
	\draw[] plot coordinates{ (0,-2) (14,-2) };  
	\draw[] plot coordinates{ (0,-3) (14,-3) };  
	\draw[] plot coordinates{ (0,-4) (14,-4) };    
	
	\draw [->,very thick] (0,-5.75) -- (2,-5.75);		
	\draw (1,-5.4) node { $Time$ };

	\draw [<->,dashed,thick ] (0,1.5) -- (3,1.5);
	\draw [<->,dashed,thick ] (3,1.5) -- (6.5,1.5);
	\draw [<->,dashed,thick ] (6.5,1.5) -- (10,1.5);
	\draw [<->,dashed,thick ] (10,1.5) -- (13.5,1.5);
	\draw [<-,dashed,thick ] (13.5,1.5) -- (14,1.5);	
	\draw[thick] plot coordinates{ (3,1.4) (3,1.6) };
	\draw[thick] plot coordinates{ (6.5,1.4) (6.5,1.6) };  
	\draw[thick] plot coordinates{ (10,1.4) (10,1.6) };  
	\draw[thick] plot coordinates{ (13.5,1.4) (13.5,1.6) };  	
	
	\draw (1.5,2) node {$Iter.\,k=0$};	
	\draw (4.75,2) node {$Iter.\,k=1$};
	\draw (8.25,2) node {$Iter.\,k=2$};
	\draw (11.75,2) node {$Iter.\,k=3$};			
		
    % Labels
	\draw (-1.5,0.5) node {$GPU.\,1$};
	\draw (-1.5,-0.5) node {$GPU.\,2$};
	\draw (-1.5,-1.5) node {$GPU.\,3$};
	\draw (-1.5,-2.5) node {$GPU.\,4$};
	\draw (-1.5,-3.5) node {$GPU.\,5$};
	\draw (-1.5,-4.5) node {$GPU.\,6$};

	% Draw first coarse propagation
	\fill[gray!90] (0,0) -- (0,1) -- (0.5,1) -- (0.5,0) -- (0,0);
	\draw[] plot coordinates{ (0,0) (0,1) (0.5,1) (0.5,0) (0,0) };  
	\fill[gray!90] (0.5,-1) -- (0.5,0) -- (1,0) -- (1,-1) -- (0.5,-1);
	\draw[] plot coordinates{ (0.5,-1) (0.5,0) (1,0) (1,-1) (0.5,-1) };  
	\fill[gray!90] (1,-2) -- (1,-1) -- (1.5,-1) -- (1.5,-2) -- (1,-2);
	\draw[] plot coordinates{ (1,-2) (1,-1) (1.5,-1) (1.5,-2) (1,-2) };  	
	\fill[gray!90] (1.5,-3) -- (1.5,-2) -- (2,-2) -- (2,-3) -- (1.5,-3);
	\draw[] plot coordinates{ (1.5,-3)  (1.5,-2)  (2,-2)  (2,-3)  (1.5,-3) };  	
	\fill[gray!90] (2,-4) -- (2,-3) -- (2.5,-3) -- (2.5,-4) -- (2,-4);
	\draw[] plot coordinates{ (2,-4)  (2,-3)  (2.5,-3)  (2.5,-4)  (2,-4) }; 
	\fill[gray!90] (2.5,-5) -- (2.5,-4) -- (3,-4) -- (3,-5) -- (2.5,-5);
	\draw[] plot coordinates{ (2.5,-5) (2.5,-4) (3,-4) (3,-5) (2.5,-5) }; 	
	
	% Draw first fine propagation
	\fill[gray!30] (0.5,0) -- (3.5,0) -- (3.5,1) -- (0.5,1) -- (0.5,0);
	\draw[] plot coordinates{ (0.5,0) (3.5,0) (3.5,1) (0.5,1) (0.5,0) };  
	\fill[gray!30] (1,-1) -- (4,-1) -- (4,0) -- (1,0) -- (1,-1);
	\draw[] plot coordinates{ (1,-1) (4,-1) (4,0) (1,0) (1,-1) };  
	\fill[gray!30] (1.5,-2) -- (4.5,-2) -- (4.5,-1) -- (1.5,-1) -- (1.5,-2);
	\draw[] plot coordinates{ (1.5,-2) (4.5,-2) (4.5,-1) (1.5,-1) (1.5,-2) };
	\fill[gray!30] (2,-3) -- (5,-3) -- (5,-2) -- (2,-2) -- (2,-3);
	\draw[] plot coordinates{ (2,-3) (5,-3) (5,-2) (2,-2) (2,-3) };		
	\fill[gray!30] (2.5,-4) -- (5.5,-4) -- (5.5,-3) -- (2.5,-3) -- (2.5,-4);
	\draw[] plot coordinates{ (2.5,-4) (5.5,-4) (5.5,-3) (2.5,-3) (2.5,-4) };	
	\fill[gray!30] (3,-5) -- (6,-5) -- (6,-4) -- (3,-4) -- (3,-5);
	\draw[] plot coordinates{ (3,-5) (6,-5) (6,-4) (3,-4) (3,-5) };		
	
	% Draw second coarse propagation
	\fill[gray!90] (4,0) -- (4,-1) -- (4.5,-1) -- (4.5,0) -- (4,0);
	\draw[] plot coordinates{  (4,0) (4,-1)  (4.5,-1)  (4.5,0)  (4,0) };  	
	\fill[gray!90] (4.5,-1) -- (4.5,-2) -- (5,-2) -- (5,-1) -- (4.5,-1);
	\draw[] plot coordinates{  (4.5,-1)  (4.5,-2)  (5,-2)  (5,-1)  (4.5,-1) }; 
	\fill[gray!90] (5,-2) -- (5,-3) -- (5.5,-3) -- (5.5,-2) -- (5,-2);
	\draw[] plot coordinates{  (5,-2)  (5,-3)  (5.5,-3)  (5.5,-2)  (5,-2) }; 	
	\fill[gray!90] (5.5,-3) -- (5.5,-4) -- (6,-4) -- (6,-3) -- (5.5,-3);
	\draw[] plot coordinates{  (5.5,-3) (5.5,-4) (6,-4) (6,-3) (5.5,-3) }; 		
	\fill[gray!90] (6,-4) -- (6,-5) -- (6.5,-5) -- (6.5,-4) -- (6,-4);
	\draw[] plot coordinates{  (6,-4) (6,-5) (6.5,-5) (6.5,-4) (6,-4) }; 		
	
	% Draw second fine propagation
	\fill[gray!30] (4.5,-1) -- (7.5,-1) -- (7.5,0) -- (4.5,0) -- (4.5,-1);
	\draw[] plot coordinates{ (4.5,-1)  (7.5,-1)  (7.5,0)  (4.5,0)  (4.5,-1) };  
	\fill[gray!30] (5,-2) -- (8,-2) -- (8,-1) -- (5,-1) -- (5,-2);
	\draw[] plot coordinates{ (5,-2)  (8,-2)  (8,-1)  (5,-1)  (5,-2) };
	\fill[gray!30] (5.5,-3) -- (8.5,-3) -- (8.5,-2) -- (5.5,-2) -- (5.5,-3);
	\draw[] plot coordinates{ (5.5,-3)  (8.5,-3)  (8.5,-2)  (5.5,-2) (5.5,-3) };		
	\fill[gray!30] (6,-4) -- (9,-4) -- (9,-3) -- (6,-3) -- (6,-4);
	\draw[] plot coordinates{ (6,-4) (9,-4) (9,-3) (6,-3) (6,-4) };	
	\fill[gray!30] (6.5,-5) -- (9.5,-5) -- (9.5,-4) -- (6.5,-4) -- (6.5,-5);
	\draw[] plot coordinates{ (6.5,-5) (9.5,-5) (9.5,-4) (6.5,-4) (6.5,-5) };	
	
	% Draw third coarse propagation	
	\fill[gray!90] (8,-1) -- (8,-2) -- (8.5,-2) -- (8.5,-1) -- (8,-1);
	\draw[] plot coordinates{  (8,-1) (8,-2) (8.5,-2) (8.5,-1) (8,-1) }; 
	\fill[gray!90] (8.5,-2) -- (8.5,-3) -- (9,-3) -- (9,-2) -- (8.5,-2);
	\draw[] plot coordinates{  (8.5,-2) (8.5,-3) (9,-3) (9,-2) (8.5,-2) }; 	
	\fill[gray!90] (9,-3) -- (9,-4) -- (9.5,-4) -- (9.5,-3) -- (9,-3);
	\draw[] plot coordinates{  (9,-3) (9,-4) (9.5,-4) (9.5,-3) (9,-3) }; 		
	\fill[gray!90] (9.5,-4) -- (9.5,-5) -- (10,-5) -- (10,-4) -- (9.5,-4);
	\draw[] plot coordinates{  (9.5,-4) (9.5,-5) (10,-5) (10,-4) (9.5,-4) }; 
	
	% Draw third fine propagation  
	\fill[gray!30] (8.5,-2) -- (11.5,-2) -- (11.5,-1) -- (8.5,-1) -- (8.5,-2);
	\draw[] plot coordinates{ (8.5,-2) (11.5,-2) (11.5,-1) (8.5,-1) (8.5,-2) };
	\fill[gray!30] (9,-3) -- (12,-3) -- (12,-2) -- (9,-2) -- (9,-3);
	\draw[] plot coordinates{ (9,-3) (12,-3) (12,-2) (9,-2) (9,-3) };		
	\fill[gray!30] (9.5,-4) -- (12.5,-4) -- (12.5,-3) -- (9.5,-3) -- (9.5,-4);
	\draw[] plot coordinates{ (9.5,-4) (12.5,-4) (12.5,-3) (9.5,-3) (9.5,-4) };	
	\fill[gray!30] (10,-5) -- (13,-5) -- (13,-4) -- (10,-4) -- (10,-5);
	\draw[] plot coordinates{ (10,-5)  (13,-5)  (13,-4)  (10,-4)  (10,-5) };
	
	% Draw fourth coarse propagation	
	\fill[gray!90] (12,-2) -- (12,-3) -- (12.5,-3) -- (12.5,-2) -- (12,-2);
	\draw[] plot coordinates{  (12,-2) (12,-3) (12.5,-3) (12.5,-2) (12,-2) }; 	
	\fill[gray!90] (12.5,-3) -- (12.5,-4) -- (13,-4) -- (13,-3) -- (12.5,-3);
	\draw[] plot coordinates{  (12.5,-3) (12.5,-4) (13,-4) (13,-3) (12.5,-3) }; 		
	\fill[gray!90] (13,-4) -- (13,-5) -- (13.5,-5) -- (13.5,-4) -- (13,-4);
	\draw[] plot coordinates{  (13,-4) (13,-5) (13.5,-5) (13.5,-4) (13,-4) }; 		
	
	% Draw fuck-ton of arrows
	\draw [->,very thick ] (0.5,0.5) -- (0.5,-0.5);
	\draw [->,very thick ] (1,-0.5) -- (1,-1.5);	
	\draw [->,very thick ] (1.5,-1.5) -- (1.5,-2.5);	
	\draw [->,very thick ] (2,-2.5) -- (2,-3.5);	
	\draw [->,very thick ] (2.5,-3.5) -- (2.5,-4.5);
	% And them dots	
	\filldraw [black] (0.5,0.5) circle (0.07);
	\filldraw [black] (1,-0.5) circle (0.07);
	\filldraw [black] (1.5,-1.5) circle (0.07);
	\filldraw [black] (2,-2.5) circle (0.07);
	\filldraw [black] (2.5,-3.5) circle (0.07);	
	
	% Draw fuck-ton of arrows
	\draw [->,very thick ] (3.5,0.5) -- (3.5,-0.5);
	\draw [->,very thick ] (4.5,-0.5) -- (4.5,-1.5);	
	\draw [->,very thick ] (5,-1.5) -- (5,-2.5);	
	\draw [->,very thick ] (5.5,-2.5) -- (5.5,-3.5);	
	\draw [->,very thick ] (6,-3.5) -- (6,-4.5);
	% And them dots	
	\filldraw [black] (3.5,0.5) circle (0.07);
	\filldraw [black] (4.5,-0.5) circle (0.07);
	\filldraw [black] (5,-1.5) circle (0.07);
	\filldraw [black] (5.5,-2.5) circle (0.07);
	\filldraw [black] (6,-3.5) circle (0.07);	
	
	% Draw fuck-ton of arrows
	\draw [->,very thick ] (7.5,-0.5) -- (7.5,-1.5);	
	\draw [->,very thick ] (8.5,-1.5) -- (8.5,-2.5);	
	\draw [->,very thick ] (9,-2.5) -- (9,-3.5);	
	\draw [->,very thick ] (9.5,-3.5) -- (9.5,-4.5);
	% And them dots	
	\filldraw [black] (7.5,-0.5) circle (0.07);
	\filldraw [black] (8.5,-1.5) circle (0.07);
	\filldraw [black] (9,-2.5) circle (0.07);
	\filldraw [black] (9.5,-3.5) circle (0.07);	
	
	% Draw fuck-ton of arrows
	\draw [->,very thick ] (11.5,-1.5) -- (11.5,-2.5);	
	\draw [->,very thick ] (12.5,-2.5) -- (12.5,-3.5);	
	\draw [->,very thick ] (13,-3.5) -- (13,-4.5);
	% And them dots	
	\filldraw [black] (11.5,-1.5) circle (0.07);
	\filldraw [black] (12.5,-2.5) circle (0.07);
	\filldraw [black] (13,-3.5) circle (0.07);
	
	% Draw legends
	\draw (0.25,0.5) node {{\scriptsize $T_{\mathcal{G}}$}};
	\draw (0.75,-0.5) node {{\scriptsize $T_{\mathcal{G}}$}};
	\draw (1.25,-1.5) node {{\scriptsize $T_{\mathcal{G}}$}};
	\draw (1.75,-2.5) node {{\scriptsize $T_{\mathcal{G}}$}};
	\draw (2.25,-3.5) node {{\scriptsize $T_{\mathcal{G}}$}};
	\draw (2.75,-4.5) node {{\scriptsize $T_{\mathcal{G}}$}};
	
	% Draw legends
	\draw (2.00,0.5) node {{\scriptsize $T_{\mathcal{F}}$}};
	\draw (2.5,-0.5) node {{\scriptsize $T_{\mathcal{F}}$}};
	\draw (3.0,-1.5) node {{\scriptsize $T_{\mathcal{F}}$}};
	\draw (3.5,-2.5) node {{\scriptsize $T_{\mathcal{F}}$}};
	\draw (4.0,-3.5) node {{\scriptsize $T_{\mathcal{F}}$}};
	\draw (4.5,-4.5) node {{\scriptsize $T_{\mathcal{F}}$}};
	
	% Draw legends
	\draw (4.25,-0.5) node {{\scriptsize $T_{\mathcal{G}}$}};
	\draw (4.75,-1.5) node {{\scriptsize $T_{\mathcal{G}}$}};
	\draw (5.25,-2.5) node {{\scriptsize $T_{\mathcal{G}}$}};
	\draw (5.75,-3.5) node {{\scriptsize $T_{\mathcal{G}}$}};
	\draw (6.25,-4.5) node {{\scriptsize $T_{\mathcal{G}}$}};
	
	% Draw legends
	\draw (6.0,-0.5) node {{\scriptsize $T_{\mathcal{F}}$}};
	\draw (6.5,-1.5) node {{\scriptsize $T_{\mathcal{F}}$}};
	\draw (7.0,-2.5) node {{\scriptsize $T_{\mathcal{F}}$}};
	\draw (7.5,-3.5) node {{\scriptsize $T_{\mathcal{F}}$}};
	\draw (8.0,-4.5) node {{\scriptsize $T_{\mathcal{F}}$}};
	
	% Draw legends
	\draw (8.25,-1.5) node {{\scriptsize $T_{\mathcal{G}}$}};
	\draw (8.75,-2.5) node {{\scriptsize $T_{\mathcal{G}}$}};
	\draw (9.25,-3.5) node {{\scriptsize $T_{\mathcal{G}}$}};
	\draw (9.75,-4.5) node {{\scriptsize $T_{\mathcal{G}}$}};
	
	% Draw legends
	\draw (10.0,-1.5) node {{\scriptsize $T_{\mathcal{F}}$}};
	\draw (10.5,-2.5) node {{\scriptsize $T_{\mathcal{F}}$}};
	\draw (11.0,-3.5) node {{\scriptsize $T_{\mathcal{F}}$}};
	\draw (11.5,-4.5) node {{\scriptsize $T_{\mathcal{F}}$}};
	
	% Draw legends
	\draw (12.25,-2.5) node {{\scriptsize $T_{\mathcal{G}}$}};
	\draw (12.75,-3.5) node {{\scriptsize $T_{\mathcal{G}}$}};
	\draw (13.25,-4.5) node {{\scriptsize $T_{\mathcal{G}}$}};
													
\end{tikzpicture}
%
%\draw plot coordinates{point sequence};	
%\draw plot ;	
%	\draw[smooth] plot coordinates{(0,0),{};
% \draw [smooth,very thick] (0,0) -- (4,-3) -- (8,-5) -- (12,-6);
% \draw[smooth,domain=0:6.5] plot function{sin(2*x)*exp(-x/4)};
% \draw[ycomb,color=gray,line width=0.5cm] plot coordinates{(1,1) (2,2) (3,3)};