Error gpu issue when more than 3 gpus enabled
VERSIONS: XMRig/2.6.0-beta1 libuv/1.19.2 CUDA/9.10 MSVC/2015
CPU: Intel(R) Celeron(R) CPU J1800 @ 2.41GHz (1) x64 -AES-NI
GPU #0: GeForce GTX 1060 6GB @ 1708/4004 MHz 16x30 6x25 arch:61 SMX:10
GPU #1: GeForce GTX 1060 6GB @ 1708/4004 MHz 16x30 6x25 arch:61 SMX:10
GPU #2: GeForce GTX 1060 6GB @ 1708/4004 MHz 16x30 6x25 arch:61 SMX:10
GPU #3: GeForce GTX 1060 6GB @ 1708/4004 MHz 16x30 6x25 arch:61 SMX:10
GPU #4: GeForce GTX 1060 6GB @ 1708/4004 MHz 16x30 6x25 arch:61 SMX:10
GPU #5: GeForce GTX 1060 6GB @ 1708/4004 MHz 16x30 6x25 arch:61 SMX:10
ALGO: cryptonight, donate=1%
POOL #1: xmr.f2pool.com:13531
COMMANDS: 'h' hashrate, 'e' health, 'p' pause, 'r' resume
[2018-04-09 17:42:07] use pool xmr.f2pool.com:13531 116.211.169.162
[2018-04-09 17:42:07] new job from xmr.f2pool.com:13531 diff 16384
[CUDA] Error gpu [CUDA] Error gpu [CUDA] Error gpu [CUDA] Error gpu 3: <cryptonight_extra_cpu_final24[CUDA] Error gpu [CUDA] Error gpu 5>:: <: <01: <373cryptonight_extra_cpu_finalcryptonight_extra_cpu_final: <: <cryptonight_extra_cpu_final ">:>:cryptonight_extra_cpu_finalcryptonight_extra_cpu_final>:unspecified launch failure373373>:>:373" " "373373 "
unspecified launch failureunspecified launch failure " "unspecified launch failurePress any key to continue . 

This log is what happens when I use more than 3 GPUs, but works fine if less than 3 GPUs, how it comes?