NVIDIA の最新のドライバ 319.49(2013年8月20日)版でも GeForce GTX Titan に正式対応していないようです。。。ただし普通に動作はします。
# nvidia-smi
Tue Aug 27 01:09:17 2013
+------------------------------------------------------+
| NVIDIA-SMI 5.319.49 Driver Version: 319.49 |
|-------------------------------+----------------------+----------------------+
| GPU Name Persistence-M| Bus-Id Disp.A | Volatile Uncorr. ECC |
| Fan Temp Perf Pwr:Usage/Cap| Memory-Usage | GPU-Util Compute M. |
|===============================+======================+======================|
| 0 GeForce GTX TITAN Off | 0000:01:00.0 N/A | N/A |
| 30% 33C N/A N/A / N/A | 68MB / 6143MB | N/A Default |
+-------------------------------+----------------------+----------------------+
| 1 GeForce GTX TITAN Off | 0000:02:00.0 N/A | N/A |
| 30% 34C N/A N/A / N/A | 14MB / 6143MB | N/A Default |
+-------------------------------+----------------------+----------------------+
+-----------------------------------------------------------------------------+
| Compute processes: GPU Memory |
| GPU PID Process name Usage |
|=============================================================================|
| 0 Not Supported |
| 1 Not Supported |
+-----------------------------------------------------------------------------+
# nvidia-smi
Tue Aug 27 01:09:17 2013
+------------------------------------------------------+
| NVIDIA-SMI 5.319.49 Driver Version: 319.49 |
|-------------------------------+----------------------+----------------------+
| GPU Name Persistence-M| Bus-Id Disp.A | Volatile Uncorr. ECC |
| Fan Temp Perf Pwr:Usage/Cap| Memory-Usage | GPU-Util Compute M. |
|===============================+======================+======================|
| 0 GeForce GTX TITAN Off | 0000:01:00.0 N/A | N/A |
| 30% 33C N/A N/A / N/A | 68MB / 6143MB | N/A Default |
+-------------------------------+----------------------+----------------------+
| 1 GeForce GTX TITAN Off | 0000:02:00.0 N/A | N/A |
| 30% 34C N/A N/A / N/A | 14MB / 6143MB | N/A Default |
+-------------------------------+----------------------+----------------------+
+-----------------------------------------------------------------------------+
| Compute processes: GPU Memory |
| GPU PID Process name Usage |
|=============================================================================|
| 0 Not Supported |
| 1 Not Supported |
+-----------------------------------------------------------------------------+