# \-ta nvidia,host and libcuda.so requirement **URL:** \ **Category:** Legacy PGI Compilers (archived)\ **Created:** [November 27, 2009, 11:42am UTC](https://forums.developer.nvidia.com/t/ta-nvidia-host-and-libcuda-so-requirement/131471 "2009-11-27T11:42:58Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![noe](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@noe](https://forums.developer.nvidia.com/u/noe)\ **Post date:** [November 27, 2009, 11:42am UTC](https://forums.developer.nvidia.com/t/ta-nvidia-host-and-libcuda-so-requirement/131471/1 "2009-11-27T11:42:58Z")
Hi, I was trying version 10.0 to create unified binaries that run with or without accelarator. It seems however, that libcuda.so is required in any case (even with ACC\_DEVICE=host) and must be installed also on platforms without accelerator. Also libcuda.so is not shipped with the compiler. Under openSUSE, for instance, it’s part of the video driver package, which would not usually be installed without accelerator. Is this the intended behaviour ? Or shouldn’t the runtime system try to avoid using any CUDA libraries when apparently no accelerator is present or wanted. Also, copying libcuda.so to some place listed in $LD\_LIBRARY\_PATH does not help, I then get the error call to cuInit returned error 100: No device Regards, Norbert ---
**Author:** ![MatColgrove](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/matcolgrove/32/14047_2.png) [@MatColgrove](https://forums.developer.nvidia.com/u/MatColgrove)\ **Post date:** [November 30, 2009, 7:43pm UTC](https://forums.developer.nvidia.com/t/ta-nvidia-host-and-libcuda-so-requirement/131471/2 "2009-11-30T19:43:30Z")
Hi Norbet, I just double checked, and did not have any problems when I created a unified binary on a system with a NVIDIA GPU and then ran it on another without a GPU. I was only able to recreate your error when I compiled with just “-ta=nvidia”. Can you please double check that you compiled with “-ta=nvidia,host”? Thanks, Mat ---
**Author:** ![noe](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@noe](https://forums.developer.nvidia.com/u/noe)\ **Post date:** [December 1, 2009, 9:16am UTC](https://forums.developer.nvidia.com/t/ta-nvidia-host-and-libcuda-so-requirement/131471/3 "2009-12-01T09:16:41Z")
Ok, one by one. I was actually using one of the official examples: hostA% pgaccelinfo | grep ‘Device Name’ Device Name: Tesla C1060 Device Name: Tesla C1060 hostA% pgfortran -o f2.uni f2.f90 -ta=nvidia,host -Minfo -fast main: 1, PGI Unified Binary version for -tp=nehalem-64 -ta=host 20, Unrolled inner loop 8 times 26, Generated an alternate loop for the loop Generated vector sse code for the loop Generated a prefetch instruction for the loop 32, Generated an alternate loop for the loop Generated vector sse code for the loop Generated a prefetch instruction for the loop 38, Loop not vectorized/parallelized: contains call main: 1, PGI Unified Binary version for -tp=nehalem-64 -ta=nvidia 20, Unrolled inner loop 8 times 25, Generating copyin(a(1:n)) Generating copyout(r(1:n)) 26, Loop is parallelizable Accelerator kernel generated 26, !$acc do parallel, vector(256) 32, Generated an alternate loop for the loop Generated vector sse code for the loop Generated a prefetch instruction for the loop 38, Loop not vectorized/parallelized: contains call hostA% ./f2.uni 100000 iterations completed 1230 microseconds on GPU 1482 microseconds on host Now hostB, same directory, same environment but no cuda installed (and no accelerator HW): hostB% pgaccelinfo | grep ‘Device Name’ hostB% ./f2.uni libcuda.so not found, exiting hostB% ACC\_DEVICE=host ./f2.uni libcuda.so not found, exiting At this point I noticed that I had not mentioned fortran in my original post and Mat is probably using C. So same test with a C example: … hostB% ./c2.uni 100000 iterations completed 1546 microseconds on GPU 1530 microseconds on host hostB% Aaaah. so it’s probably a fortran runtime problem. Also interesting: hostB reports having spent some time on the non-existant GPU. But that’s off-topic. Norbert ---
**Author:** ![MatColgrove](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/matcolgrove/32/14047_2.png) [@MatColgrove](https://forums.developer.nvidia.com/u/MatColgrove)\ **Post date:** [December 1, 2009, 4:38pm UTC](https://forums.developer.nvidia.com/t/ta-nvidia-host-and-libcuda-so-requirement/131471/4 "2009-12-01T16:38:03Z")
Hi Norbert, The example code you are using has the following line: ```nohighlight call acc_init( acc_device_nvidia ) ``` In other words, by using this runtime call, the code is forcing the use of the NVIDIA device. Changing acc\_init to use “acc\_device\_default” will allow you to use the unified binary. Note that the c2 C example has the same issue. Hope this helps, Mat