Maya (Arnold) to Nuke best EXR setting for time

Compression Types:
Run Length Encoding (RLE) : This is a basic form of compression that is comparable to that used by standard Targa files.
Zip (16 Scanline) : deflate compression applied to blocks of 16 scanlines at time. This tends to be the most effective style of compression to use with rendered images that do not have film grain applied.
Zips (1 Scanline) : deflate compression with zlib wrapper applied to individual scanlines (not based on the ZIP file format despite its name).

Not great for compositing packages such as Nuke or Fusion

AutoCrop :
If you have a lot of black space this might help cropping out un-used pixels.

Merge AOVs :
This create one EXR file instead multiple pre channel/pass

Arnold to Nuke EXR

Bit DepthCompressionGBTitledCropLoad SecMemWrite sec
32bitZip (16 scanline)1.7Tiledno3.231.6 GB59.2
32 bitZip (16 scanline)1.76Scanlineno1.061.6 GB56.5
32 bitZipS (1 Scanline)1.7Tiledno1.831.6 GB67.86
32 bitZipS (1 Scanline)1.76Scanlineno0.018.18 KB52.92
32 bitZipS (1 Scanline)1.76ScanlineYes0.078.18 KB52.92
32 bitnone14Scanlineno0.088.18 KB174.92
16 bitZip (16 scanline)0.51Tiledno0.781.6 GB51.26
16 bitZipS (1 Scanline)0.53Scanlineno0.058.18 KB43.1
16 bitZipS (1 Scanline)
0.53Scanlineyes0.058.18 KB42.95