331.XX Branch and SLI... (Just doesn't enable)

Is there any reason across all released drivers to date under the NVIDIA’s 331.XX branch SLI does not enable? In fact the only real branch that SLI has worked for me is the 319.XX branch. All other’s remain in single GPU mode despite xorg configuration updated with SLI required variables.

If I change to the 319.XX branch using the exact same procedure’s SLI enables absolutely fine.

Anyhow be nice to have some clarification as to why SLI appears not to work (atleast under my configuration) with NVIDIA’s Latest Long Lived Branch that is 331.XX (including latest 331.20).

Procedure:
sudo nvidia-xconfig --sli=On

(However I usually opt for SFR SLI Rendering using “–sli=SFR” since this yielded much better performance under SLI)

OS:
Ubuntu 13.04
3.8.0-33-generic
x86_64

System Spec:
Intel i7 2700K OC@4.6GHZ (WC)
Asrock Z68 Extreme4 Gen3 1155 Motherboard
8GB G.Skill RipjawX OC@1866MHZ (2x 4GB)
2x Nvidia Gainward GTX570 Golden Sample Goes Like Hell Edition (SLI)
Corsair TX750w PSU

Best Regards,

s89

SLI enables just fine for me in ubuntu 13.10 with 331.20 driver, problem is it’s useless because theres no profiles for games, so, most of the time performance is worse than one card.

Sli does not enable at all in any branch other then 319.XX for me.

Driver 319.XX:

01:00.0 VGA compatible controller: NVIDIA Corporation GF110 [GeForce GTX 570] (rev a1)
02:00.0 VGA compatible controller: NVIDIA Corporation GF110 [GeForce GTX 570] (rev a1)

01:00.0 VGA compatible controller: NVIDIA Corporation GF110 [GeForce GTX 570] (rev a1) (prog-if 00 [VGA controller])
Subsystem: CardExpert Technology Device 0801
Flags: bus master, fast devsel, latency 0, IRQ 16
Memory at f6000000 (32-bit, non-prefetchable)
Memory at e8000000 (64-bit, prefetchable)
Memory at f0000000 (64-bit, prefetchable)
I/O ports at e000
[virtual] Expansion ROM at f7000000 [disabled]
Capabilities:
Kernel driver in use: nvidia

01:00.1 Audio device: NVIDIA Corporation GF110 High Definition Audio Controller (rev a1)
Subsystem: CardExpert Technology Device 0801
Flags: bus master, fast devsel, latency 0, IRQ 17
Memory at f7080000 (32-bit, non-prefetchable)
Capabilities:
Kernel driver in use: snd_hda_intel

02:00.0 VGA compatible controller: NVIDIA Corporation GF110 [GeForce GTX 570] (rev a1) (prog-if 00 [VGA controller])
Subsystem: CardExpert Technology Device 0801
Flags: bus master, fast devsel, latency 0, IRQ 17
Memory at f4000000 (32-bit, non-prefetchable)
Memory at d8000000 (64-bit, prefetchable)
Memory at e0000000 (64-bit, prefetchable)
I/O ports at d000
[virtual] Expansion ROM at f5000000 [disabled]
Capabilities:
Kernel driver in use: nvidia

02:00.1 Audio device: NVIDIA Corporation GF110 High Definition Audio Controller (rev a1)
Subsystem: CardExpert Technology Device 0801
Flags: bus master, fast devsel, latency 0, IRQ 18
Memory at f5080000 (32-bit, non-prefetchable)
Capabilities:
Kernel driver in use: snd_hda_intel

Driver 331.XX:

Log coming…