According to the specs, my HD 4870 X2 graphics card should have 2 GB of memory. Yet I can only make use of 1 GB in CAL. For example, I can allocate 61 textures of size 1024x1024 and type float4, which would correspond do 61*16 MB = 976 MB. Allocating more memory fails, with calGetErrorString() returning the error message 'Operational error'.
Assigning the memory equally to both gpu cores does not help, in that case I can allocate 30 textures on each core.
Any ideas why I cannot allocate more memory? Can someone confirm these results? I am using 64 bit gentoo linux.