sampler samp0 : register(s0) = sampler_state
{
    ...//set filtering, address modes...
};

sampler samp1 : register(s1) = sampler_state
{
    ...//set filtering, address modes...
};
...and so on

sampler arrSamp[4];

dev->SetRenderTarget(0, rt0);
dev->SetRenderTarget(1, rt1);
dev->SetRenderTarget(2, rt2);
dev->SetRenderTarget(3, rt3);// all rts are of the same size
D3DRECT rcs[4];
rcs[0].x1 = 0;
rcs[0].x2 = rtSize;
rcs[0].y1 = 0;
rcs[0].y2 = rtSize;
rcs[1].x1 = 0;
rcs[1].x2 = rtSize;
rcs[1].y1 = 0;
rcs[1].y2 = rtSize;
rcs[2].x1 = 0;
rcs[2].x2 = rtSize;
rcs[2].y1 = 0;
rcs[2].y2 = rtSize;
rcs[3].x1 = 0;
rcs[3].x2 = rtSize;
rcs[3].y1 = 0;
rcs[3].y2 = rtSize;
HRESULT hr = dev->Clear(4, rcs, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, 0x00FFFFFF, 1.0f, 0L);

// Vertex shader// here Depth is floatOUT.Depth              = (OUT.Position.z / OUT.Position.w);//Pixel shaderOUT.Color = float4(IN.Depth, 1.0f, 1.0f, 1.0f);

// Vertex shader// here Depth is float2OUT.Depth.xy            = OUT.Position.zw;//Pixel shaderOUT.Color = float4(IN.Depth.x / IN.Depth.y, 1.0f, 1.0f, 1.0f);