# Driver 331.20 or 331.38 + CUDA + Base Mosaic = Freeze

**URL:** <https://forums.developer.nvidia.com/t/driver-331-20-or-331-38-cuda-base-mosaic-freeze/32120>\
**Category:** Linux\
**Created:** [January 29, 2014, 8:09pm UTC](https://forums.developer.nvidia.com/t/driver-331-20-or-331-38-cuda-base-mosaic-freeze/32120 "2014-01-29T20:09:46Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![0chi](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@0chi](https://forums.developer.nvidia.com/u/0chi)\
**Post date:** [January 29, 2014, 8:09pm UTC](https://forums.developer.nvidia.com/t/driver-331-20-or-331-38-cuda-base-mosaic-freeze/32120/1 "2014-01-29T20:09:46Z")

</div>

Hello,

since driver version 331.20, I’m experiencing hard X freezes and Xid errors when running a CUDA (or OpenCL) application when Base Mosaic is activated (2 cards, 3 monitors). Downgrading to 325.15 or disabling Base Mosaic helps. A rather minimal example triggering the errors is to run the “vectorAdd” example from the CUDA 5.5 package.

SSHing into the machine is possible. The system log is spammed with

```auto
NVRM: Xid (0000:04:00): 38, 0000 00000000 00000000 00000000 00000000 00000000

```

The relevant section from my xorg.conf:

```auto
Section "Device"
  Identifier "GeForceSLI"
  Driver "nvidia"
  BusID "PCI:3:0:0"
  Option "UseEdidDpi" "false"
  Option "DPI" "96 x 96"
  Option "Coolbits" "4"
  Option "SLI" "Mosaic"
  Option "BaseMosaic" "true"
  Option "MetaModes" "GPU-0.DFP-3: 1680x1050+0+0, GPU-0.DFP-0: 1680x1050+1680+0, GPU-1.DFP-0: 1680x1050+3360+0"
EndSection

```

Further specs:  
2x EVGA GeForce 670 GTX  
Arch Linux, Kernel 3.12.9  
Xorg 1.15.0

Does anyone have similar problems in such a configuration?

---

<div class="post-metadata">

**Author:** ![rickyzhang](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/rickyzhang/32/71248_2.png) [@rickyzhang](https://forums.developer.nvidia.com/u/rickyzhang)\
**Post date:** [February 2, 2014, 7:16am UTC](https://forums.developer.nvidia.com/t/driver-331-20-or-331-38-cuda-base-mosaic-freeze/32120/2 "2014-02-02T07:16:35Z")

</div>

I experienced the same problem as you did in fedora 20. Mine configuration is GTX590 + dual monitors. GTX590 contains dual GPUs. Disable mosaic do helps.

I guess that 331.x cuda driver is for 6.0. It may have backward compatibility issues.

In any case, I encountered problems when trying to downgrade to 325.15.

---

<div class="post-metadata">

**Author:** ![rickyzhang](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/rickyzhang/32/71248_2.png) [@rickyzhang](https://forums.developer.nvidia.com/u/rickyzhang)\
**Post date:** [February 20, 2014, 2:41am UTC](https://forums.developer.nvidia.com/t/driver-331-20-or-331-38-cuda-base-mosaic-freeze/32120/3 "2014-02-20T02:41:57Z")

</div>

The latest driver 331.49 has resolved the problem.