Set pixel in RFloat texture - unity3d

Question

I want to implement an algorithm on GPU using Graphics.Blit. The input values are floats and output values are also float. I Create a texture with RFloat format and want to set values for every pixel. How can I set that? According to unity manual SetPixels doesn't work:
This function works only on ARGB32, RGB24 and Alpha8 texture formats.
For other formats SetPixels is ignored.
The algorithm needs float precision so the neither of these formats are usable. So how can it be done?
EDIT: After more struggle with unity RenderTextures, Here is the code I came up with to transfer data to GPU.
int res=512;
Texture2D tempTexture= new Texture2D(res, res, TextureFormat.RFloat, false);
public void ApplyHeightsToRT(float[,] heights, RenderTexture renderTexture)
{
RenderTexture.active = renderTexture;
Texture2D tempTexture = new Texture2D(res, res, TextureFormat.RFloat, false);
tempTexture.ReadPixels(new Rect(0, 0, renderTexture.width, renderTexture.height), 0, 0
, false);
for (int i = 0; i < tempTexture.width; i++)
for (int j = 0; j < tempTexture.height; j++)
{
tempTexture.SetPixel(i, j, new Color(heights[i, j], 0, 0, 0));
}
tempTexture.Apply();
RenderTexture.active = null;
Graphics.Blit(tempTexture, renderTexture);
}
This code successfully uploads the tempTexture to RenderTexture. The inverse operation is similarly done with the following method (RenderTexture is copied to tempTexture):
public void ApplyRTToHeights(RenderTexture renderTexture, float[,] heights)
{
RenderTexture.active = renderTexture;
tempTexture.ReadPixels(new Rect(0, 0, renderTexture.width, renderTexture.height), 0, 0
, false);
for (int i = 0; i < tempTexture.width; i++)
for (int j = 0; j < tempTexture.height; j++)
{
heights[i, j]=tempTexture.GetPixel(i, j).r;
}
RenderTexture.active = null;
}
To test the code I get the heightmap of a terrain then I call the first method to fill the RenderTexture with heightmap. Then I call the second method to get pixels from RenderTexture and put them on the terrain. It should do nothing. Right?
Actually calling the two methods one after another would flip the terrain heightmap and also create banding artifacts. Very weird. After further investigation the reason for flip turned out to be a formatting problem. The tempTexture that is created above the two methods is actually an ARGB32 texture not the RFloat I hoped it would be.
This explains the flips. After changing the code of tempTexture to be a ARGB32 texture and changing RenderTexture to be RGBA32, flip behaviour gone away. Now there is only banding artifacts:
And that would be understandable since I'm using only 8 bits (red channel) of both tempTexture and RenderTexture.
Now the problem is not about setting data on a RFloat texture. The problem is RFloat textures are not supported in my graphics card and probably many other different graphic devices. The problem is to find a way to transfer float arrays to the RenderTexture.