I've tried what I thought would fix this as my performance is subpar in my game, and I have a pretty okay laptop. Plays TS4 perfectly, anyway haha.
I have an alienware and it has the 965m, sims 3 runs pretty badly, honestly. I cap my game to 30 and once inside the game it can't hold a steady 30 frames and drops into the low 20s. I also can't use a HQ mod, which is just strange because I was running this game at a almost steady 30 on my old laptop with an integrated ATI. I have changed the Nvidia settings to tell it to use nvidia, and my logs show the nvidia card as being the one it's using. The taskbar shows slight evidence to the contrary, though. It shows the intel symbol next to my battery and usually that would be the nvidia card there, so I feel like it's still using the Intel somehow? Or is below 30 average for this game? I inserted some of my dxdiag below.
I have base game, WA, Amb, LN, Generations, Pets, Seasons, supernatural, University, and island paradise installed

Operating System: Windows 10 Home 64-bit (10.0, Build 10586) (10586.th2_release_sec.160223-1728)
Language: English (Regional Setting: English)
System Manufacturer: Alienware
System Model: Alienware 15
BIOS: A04
Processor: Intel(R) Core(TM) i5-4210H CPU @ 2.90GHz (4 CPUs), ~2.9GHz
Memory: 8192MB RAM
Available OS Memory: 8078MB RAM
Page File: 4056MB used, 5301MB available
Windows Dir: C:\WINDOWS
DirectX Version: 12
DX Setup Parameters: Not found
User DPI Setting: Using System DPI
System DPI Setting: 120 DPI (125 percent)
DWM DPI Scaling: UnKnown
Miracast: Available, with HDCP
Microsoft Graphics Hybrid: Supported
DxDiag Version: 10.00.10586.0000 64bit Unicode
Display Devices
---------------
Card name: Intel(R) HD Graphics 4600
Manufacturer: Intel Corporation
Chip type: Intel(R) HD Graphics Family
DAC type: Internal
Device Type: Full Device
Device Key: Enum\PCI\VEN_8086&DEV_0416&SUBSYS_06851028&REV_06
Display Memory: 6010 MB
Dedicated Memory: 1971 MB
Shared Memory: 4038 MB
Current Mode: 1920 x 1080 (32 bit) (60Hz)
Monitor Name: Generic PnP Monitor
Monitor Model: unknown
Monitor Id: SDC4C48
Native Mode: 1920 x 1080(p) (59.996Hz)
Output Type: Internal
Driver Name: igdumdim64.dll,igd10iumd64.dll,igd10iumd64.dll,igd12umd64.dll,igdumdim32,igd10iumd32,igd10iumd32,igd12umd32
Driver File Version: 20.19.0015.4331 (English)
Driver Version: 20.19.15.4331
DDI Version: 12
Feature Levels: 12.1,12.0,11.1,11.0,10.1,10.0,9.3,9.2,9.1
Driver Model: WDDM 2.0
Graphics Preemption: Primitive
Compute Preemption: Thread group
Miracast: Supported
Hybrid Graphics GPU: Integrated
Power P-states: Not Supported
Driver Attributes: Final Retail
Driver Date/Size: 11/18/2015 12:00:00 AM, 35016296 bytes
WHQL Logo'd: Yes
WHQL Date Stamp:
Device Identifier: {D7B71E3E-5099-11CF-D06A-88261CC2C735}
Vendor ID: 0x10DE
Device ID: 0x13D9
SubSys ID: 0x06851028
Revision ID: 0x00A1
Driver Strong Name: oem13.inf:5f63e534dd929195:iHSWM_w10:20.19.15.4331:pci\ven_8086&dev_0416
Rank Of Driver: 00D12001
Video Accel: ModeMPEG2_A ModeMPEG2_C ModeWMV9_C ModeVC1_C
DXVA2 Modes: DXVA2_ModeMPEG2_VLD DXVA2_ModeVC1_D2010 DXVA2_ModeVC1_VLD DXVA2_ModeH264_VLD_Stereo_Progressive_NoFGT DXVA2_ModeH264_VLD_Stereo_NoFGT DXVA2_ModeH264_VLD_NoFGT DXVA2_ModeHEVC_VLD_Main DXVA2_ModeMPEG4pt2_VLD_Simple DXVA2_ModeMPEG4pt2_VLD_AdvSimple_NoGMC
Deinterlace Caps: {BF752EF6-8CC4-457A-BE1B-08BD1CAEEE9F}: Format(In/Out)=(YUY2,YUY2) Frames(Prev/Fwd/Back)=(0,0,1) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY VideoProcess_AlphaBlend DeinterlaceTech_EdgeFiltering
{335AA36E-7884-43A4-9C91-7F87FAF3E37E}: Format(In/Out)=(YUY2,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY VideoProcess_AlphaBlend DeinterlaceTech_BOBVerticalStretch
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(YUY2,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY VideoProcess_AlphaBlend
{BF752EF6-8CC4-457A-BE1B-08BD1CAEEE9F}: Format(In/Out)=(UYVY,YUY2) Frames(Prev/Fwd/Back)=(0,0,1) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY VideoProcess_AlphaBlend DeinterlaceTech_EdgeFiltering
{335AA36E-7884-43A4-9C91-7F87FAF3E37E}: Format(In/Out)=(UYVY,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY VideoProcess_AlphaBlend DeinterlaceTech_BOBVerticalStretch
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(UYVY,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY VideoProcess_AlphaBlend
{BF752EF6-8CC4-457A-BE1B-08BD1CAEEE9F}: Format(In/Out)=(YV12,YUY2) Frames(Prev/Fwd/Back)=(0,0,1) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY VideoProcess_AlphaBlend DeinterlaceTech_EdgeFiltering
{335AA36E-7884-43A4-9C91-7F87FAF3E37E}: Format(In/Out)=(YV12,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY VideoProcess_AlphaBlend DeinterlaceTech_BOBVerticalStretch
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(YV12,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY VideoProcess_AlphaBlend
{BF752EF6-8CC4-457A-BE1B-08BD1CAEEE9F}: Format(In/Out)=(NV12,YUY2) Frames(Prev/Fwd/Back)=(0,0,1) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY VideoProcess_AlphaBlend DeinterlaceTech_EdgeFiltering
{335AA36E-7884-43A4-9C91-7F87FAF3E37E}: Format(In/Out)=(NV12,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY VideoProcess_AlphaBlend DeinterlaceTech_BOBVerticalStretch
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(NV12,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY VideoProcess_AlphaBlend
{BF752EF6-8CC4-457A-BE1B-08BD1CAEEE9F}: Format(In/Out)=(IMC1,YUY2) Frames(Prev/Fwd/Back)=(0,0,1) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY VideoProcess_AlphaBlend DeinterlaceTech_EdgeFiltering
{335AA36E-7884-43A4-9C91-7F87FAF3E37E}: Format(In/Out)=(IMC1,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY VideoProcess_AlphaBlend DeinterlaceTech_BOBVerticalStretch
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(IMC1,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY VideoProcess_AlphaBlend
{BF752EF6-8CC4-457A-BE1B-08BD1CAEEE9F}: Format(In/Out)=(IMC2,YUY2) Frames(Prev/Fwd/Back)=(0,0,1) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY VideoProcess_AlphaBlend DeinterlaceTech_EdgeFiltering
{335AA36E-7884-43A4-9C91-7F87FAF3E37E}: Format(In/Out)=(IMC2,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY VideoProcess_AlphaBlend DeinterlaceTech_BOBVerticalStretch
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(IMC2,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY VideoProcess_AlphaBlend
{BF752EF6-8CC4-457A-BE1B-08BD1CAEEE9F}: Format(In/Out)=(IMC3,YUY2) Frames(Prev/Fwd/Back)=(0,0,1) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY VideoProcess_AlphaBlend DeinterlaceTech_EdgeFiltering
{335AA36E-7884-43A4-9C91-7F87FAF3E37E}: Format(In/Out)=(IMC3,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY VideoProcess_AlphaBlend DeinterlaceTech_BOBVerticalStretch
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(IMC3,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY VideoProcess_AlphaBlend
{BF752EF6-8CC4-457A-BE1B-08BD1CAEEE9F}: Format(In/Out)=(IMC4,YUY2) Frames(Prev/Fwd/Back)=(0,0,1) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY VideoProcess_AlphaBlend DeinterlaceTech_EdgeFiltering
{335AA36E-7884-43A4-9C91-7F87FAF3E37E}: Format(In/Out)=(IMC4,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY VideoProcess_AlphaBlend DeinterlaceTech_BOBVerticalStretch
{5A54A0C9-C7EC-4BD9-8EDE-F3C75DC4393B}: Format(In/Out)=(IMC4,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY VideoProcess_AlphaBlend
D3D9 Overlay: Not Supported
DXVA-HD: Supported
DDraw Status: Enabled
D3D Status: Enabled
AGP Status: Enabled
MPO Caps: Not Supported
MPO Stretch: Not Supported
MPO Media Hints: Not Supported
MPO Formats: Not Supported

Card name: NVIDIA GeForce GTX 965M
Manufacturer: NVIDIA
Chip type: GeForce GTX 965M
DAC type: Integrated RAMDAC
Device Type: Render-Only Device
Device Key: Enum\PCI\VEN_10DE&DEV_13D9&SUBSYS_06851028&REV_A1
Display Memory: 6010 MB
Dedicated Memory: 1971 MB
Shared Memory: 4038 MB
Current Mode: n/a
Driver Name: nvd3dumx,nvwgf2umx,nvwgf2umx,nvwgf2umx,nvd3dum,nvwgf2um,nvwgf2um,nvwgf2um
Driver File Version: 10.18.0013.6472 (English)
Driver Version: 10.18.13.6472
DDI Version: 12
Feature Levels: 12.1,12.0,11.1,11.0,10.1,10.0,9.3,9.2,9.1
Driver Model: WDDM 2.0
Graphics Preemption: DMA
Compute Preemption: DMA
Miracast: Not Supported by Graphics driver
Hybrid Graphics GPU: Discrete
Power P-states: Not Supported
Driver Attributes: Final Retail
Driver Date/Size: 3/21/2016 12:00:00 AM, 17369448 bytes
WHQL Logo'd: Yes
WHQL Date Stamp:
Device Identifier: n/a
Vendor ID: 0x10DE
Device ID: 0x13D9
SubSys ID: 0x06851028
Revision ID: 0x00A1
Driver Strong Name: oem49.inf:0f066de35be7b214:Section109:10.18.13.6472:pci\ven_10de&dev_13d9&subsys_06851028
Rank Of Driver: 00D10001
Video Accel: n/a
DXVA2 Modes: DXVA2_ModeMPEG2_VLD DXVA2_ModeVC1_D2010 DXVA2_ModeVC1_VLD DXVA2_ModeH264_VLD_Stereo_Progressive_NoFGT DXVA2_ModeH264_VLD_Stereo_NoFGT DXVA2_ModeH264_VLD_NoFGT DXVA2_ModeHEVC_VLD_Main DXVA2_ModeMPEG4pt2_VLD_Simple DXVA2_ModeMPEG4pt2_VLD_AdvSimple_NoGMC
Deinterlace Caps: n/a
D3D9 Overlay: n/a
DXVA-HD: n/a
DDraw Status: Enabled
D3D Status: Enabled
AGP Status: Enabled
MPO Caps: Not Supported
MPO Stretch: Not Supported
MPO Media Hints: Not Supported
MPO Formats: Not Supported

You have dual gpus switchable laptop, Intel HD4600 and Nvidia GTX965M, you need to install the Intel's proper driver first for win 10, after that then install the latest Nvidia driver, some games won't run the Nvidia with this dual switchable setup even though you've set it up accordingly, it keeps running the Intel instead because some of those games doesn't recognize this dual switchable gpus setup, like the very first Company of Heroes and TS3 very first patch generation, they keep switching back to Intel even you tell the Nvidia control panel to use the GTX965M you have.

To make this setup work, first you have to install the Intel HD driver first then followed by the Nvidia, you need the Intel HD driver because the trigger to activate the Nvidia is in the Intel driver's pack, and secondly your TS3 need to have the more recent patch, I recommend the 1.67 patch, then install FPS limiter to protect your gpus. You might want to read this thread http://modthesims.info/showthread.php?t=570283 for more details, your case is quite similar.

Once you got this setup work accordingly, you still need to edit the GraphicsCards.sgr file for TS3 to run your GTX965M, GTX965M is not on its list, the closest one to yours would be the GTX460M on its list, put your GTX965M device ID replacing GTX460's device ID, the best TS3 can run your GTX965M would treat it as GTX460M.

Alrighty, so I tried out that stuff and noticed no difference. I did switch it to start up on the intel though, and that was a lot slower. So I guess it is using the right card, only thing is that now it won't let me save my options and the game always starts in low settings now haha. But is it necessarily normal for the frame rate to drop whenever the camera moves etc. and then spike back up to 30? it usually dips into the 20's. I haven't played this game in ages, so I guess I could be thinking with rose colored glasses. Without my FPS limiter it's in the 100s and flies up and down all over the place.

EDIT: could be worth adding I have a quad core processor I'm pretty sure, and I haven't done anything in terms of memory editing or if there's anything to make it use more of the processor. I've been on a long extended leave from TS3, so I could be missing something big haha.

You can check it if you're currently using the right card when playing TS3 in your DeviceConfig in your TS3 Docs folder, if it shows your Nvidia GTX965M card, that means you are done with both of drivers issues, it just a matter to make your GTX965M works as GTX460M. When you get this right you'll have a reasonable FPS, I personally set it to 30 FPS max, some people do 60 FPS but I'll stay with 30, don't go without FPS limiter, it will burnt your GTX965M, that's why I got here because TS3 burnt my old GTX280..

You can select manually in NVidia Panel, installed auto with drivers (ATI has it's own too) which GPU will be used for particular program. There's sometimes a problem in windowed mode on laptops - sometimes this association is not recognised properly and stubborn Intel wins. But in fullscreen mode it's not a case.

And there's also Riva Tuner Statistics Server (for example, if FPSLimiter refuse cooperation) which allows you to set demanded FPS while GPU works with particular program.