Hello, OpenEXR devs. I've been doing some comparative rendering tests I've found something a bit surprising.
TIFF and EXR texture access *times* seems more or less the same, which is fine because the underlying data is equivalent. (Same data type, compression, tile size, etc.) But the RAM overhead seems much higher for EXRs. We've got a 9GB render using TIFFs and a 13GB render using EXRs.
Does anyone have some theories why EXR texture access is requiring 4GB more memory?
Prman-20.11, OSL shaders, OIIO/TIFF textures:
OpenImageIO ImageCache statistics (shared) ver 1.7.3dev
Options: max_memory_MB=4000.0 max_open_files=100 autotile=64
autoscanline=0 automip=1 forcefloat=0 accept_untiled=1
accept_unmipped=1 read_before_insert=0 deduplicate=1
unassociatedalpha=0 failure_retries=0
Images : 1957 unique
ImageInputs : 136432 created, 100 current, 796 peak
Total size of all images referenced : 166.0 GB
Read from disk : 55.5 GB
File I/O time : 7h 2m 33.9s (16m 54.2s average per thread)
File open time only : 27m 44.0s
Prman-20.11, OSL shaders, OIIO/EXR textures:
real 00:21:14
OpenImageIO ImageCache statistics (shared) ver 1.7.3dev
Options: max_memory_MB=4000.0 max_open_files=100 autotile=64
autoscanline=0 automip=1 forcefloat=0 accept_untiled=1
accept_unmipped=1 read_before_insert=0 deduplicate=1
unassociatedalpha=0 failure_retries=0
Images : 1957 unique
ImageInputs : 133168 created, 100 current, 771 peak
Total size of all images referenced : 166.0 GB
Read from disk : 55.5 GB
File I/O time : 6h 15m 42.1s (15m 1.7s average per thread)
File open time only : 1m 22.5s