CUDA Memory allocation issue on GTX 850M on Windows 7 (64)

Hi guys,

We have run into a weird issue where we are unable to allocate more than 2GB of memory on 850M that has 4 GBs. Just to make sure that there is nothing wrong with our program, we wrote a small test app that keeps alloc’ing memory until it receives out of memory error. It works fine on Windows 8, however on Windows 7, it throws error after allocating 2 Gbs, and yet it shows it has 2 Gb free memory available. My question is why I am unable to allocate more than 2Gb memory on Windows 7? Another clue: I rolled back my driver and found out that I get this behavior starting from nvidia driver 352.86 all the way to the latest driver. On older drivers, it works like a charm even on Win 7.

Thanks in advance.