Run DXDIAG, save the text file and look at it. It will show the amount of dedicated video RAM, as well as the total video RAM.
Have you tried disabling SLI? Enabling it?
I hope this will answer your question... No sir, I haven't tried disabling SLI, I don't know what that is... sorry, I don't know anything about computers. Their is alot of stuff after I ran the DXDIAG thing, but this is the only thing I saw that said something about my cards. I would of pasted the whole thing... but their is alot of stuff and it would take two pages to put it all here... I think.
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System Information
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Time of this report: 2/4/2016, 11:43:34
Machine name: XXXXXXXXXX-PC
Operating System: Windows 7 Home Premium 64-bit (6.1, Build 7601) Service Pack 1 (7601.win7sp1_gdr.151230-0600)
Language: English (Regional Setting: English)
System Manufacturer: Gigabyte Technology Co., Ltd.
System Model: To be filled by O.E.M.
BIOS: BIOS Date: 07/16/12 16:20:51 Ver: 04.06.04
Processor: Intel(R) Core(TM) i7-3820 CPU @ 3.60GHz (8 CPUs), ~3.8GHz
Memory: 32768MB RAM
Available OS Memory: 16384MB RAM
Page File: 2342MB used, 30424MB available
Windows Dir: C:\Windows
DirectX Version: DirectX 11
DX Setup Parameters: Not found
User DPI Setting: Using System DPI
System DPI Setting: 96 DPI (100 percent)
DWM DPI Scaling: Disabled
DxDiag Version: 6.01.7601.17514 32bit Unicode
------------
DxDiag Notes
------------
Display Tab 1: No problems found.
Sound Tab 1: No problems found.
Sound Tab 2: No problems found.
Sound Tab 3: No problems found.
Input Tab: No problems found.
--------------------
DirectX Debug Levels
--------------------
Direct3D: 0/4 (retail)
DirectDraw: 0/4 (retail)
DirectInput: 0/5 (retail)
DirectMusic: 0/5 (retail)
DirectPlay: 0/9 (retail)
DirectSound: 0/5 (retail)
DirectShow: 0/6 (retail)
---------------
Display Devices
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Card name: NVIDIA GeForce GTX 650
Manufacturer: NVIDIA
Chip type: GeForce GTX 650
DAC type: Integrated RAMDAC
Device Key: Enum\PCI\VEN_10DE&DEV_0FC6&SUBSYS_26513842&REV_A1
Display Memory: 4038 MB
Dedicated Memory: 1990 MB
Shared Memory: 2048 MB
Current Mode: 1680 x 1050 (32 bit) (59Hz)
Monitor Name: Generic PnP Monitor
Monitor Model: HP w2338h
Monitor Id: HWP281B
Native Mode: 1920 x 1080(p) (60.000Hz)
Output Type: HD15
Driver Name: nvd3dumx.dll,nvwgf2umx.dll,nvwgf2umx.dll,nvd3dum,nvwgf2um,nvwgf2um
Driver File Version: 10.18.0013.5906 (English)
Driver Version: 10.18.13.5906
DDI Version: 11
Driver Model: WDDM 1.1
Driver Attributes: Final Retail
Driver Date/Size: 11/24/2015 18:10:29, 15717672 bytes
WHQL Logo'd: Yes
WHQL Date Stamp:
Device Identifier: {D7B71E3E-4C86-11CF-E04C-5C061CC2C735}
Vendor ID: 0x10DE
Device ID: 0x0FC6
SubSys ID: 0x26513842
Revision ID: 0x00A1
Driver Strong Name: oem34.inf:NVIDIA_Devices.NTamd64.6.1:Section032:10.18.13.5906:pci\ven_10de&dev_0fc6
Rank Of Driver: 00E62001