2xSLI GTX 670 GPU Memory Clock 0.0 MHz

[cminusincplusplus]

Just built my first PC, read about overlocking CPU etc. but didn't try OC my GPU's yet. I probably lack PSU power for that. Anyway, I was checking CPU-Z and saw my GPU Memory Clock on my first card never changes and remains at 0.0MHz. Downloaded GPU-Z and MSI Afterburner which give the same results.

This probably isn't normal is it?

Under load (running Insurgency)

PC Specs
+CPU: Intel Core i7-3820 3.6GHz Quad-Core Processor @ 4.62GHz
+CPU Cooler: Noctua NH-D15 82.5 CFM
+MOBO: Asus P9X79 ATX LGA2011
+Video Card: Asus GeForce GTX 670 2GB Video Card (2-Way SLI)
+Memory: Corsair Vengeance LP 16GB (2 x 8GB) DDR3-1600
+SSD: Samsung 840/850 Pro/EVO Series 128GB/250 2.5"
+HDD: Western Digital Caviar Green 2TB 3.5" 5400RPM
+Case: Thermaltake Core V71 ATX Full Tower
+Monitor: BenQ XL2420G 144Hz 24.0"
+Monitor 2: LG 2342T Flatron
+Power Supply: Corsair 760W 80+ Platinum Certified Fully-Modular ATX
+OS: Microsoft Windows 7 Home Premium SP1 OEM (64-bit)
+Keyboard: Microsoft Natural Ergonomic 4000 Wired
+Mouse: Logitech G500 Wired Laser Mouse
+Extra case fans: Cooler Master 120mm a12015-08CB-3BN F1 & Cooler Master 140mm a14025-10CB-3BN F1
+Headset: Steelseries 4H

 

[Kliqx]

I am no expert but I'm assuming 1 card is doing the work and the other is just idling because it is under no real stress.
If your card still works perfectly and has no performance drops or heat spikes I see no noticeable issue with it.
Because the card is not being used, try playing a graphic intensive game and check results while playing.
There should be no issue overall but just check it may be a small bug or something with the SLI in GPU-Z

 

[cminusincplusplus]

Edit: 3DMark Firestrike results
http://www.3dmark.com/3dm/8463971