License key - NVENC on NVIDIA GTX 750 TI (Maxwell)

Hi Nvidia,

we are a company which are trying to use the nvenc on the NVIDIA GTX 750 TI (Maxwell) to transcode videos.

Currently we try it with only this card but if we have success we would like to purchase hundreds of this card.

We run into trouble using “nvenc”, here is the log:

user@nvenc:~/Downloads/nvenc_3.0_linux_sdk/Samples/nvEncodeApp$ ./

>> GetNumberEncoders() has detected 1 CUDA capable GPU device(s) <<
  [ GPU #0 - < D16P2-30 > has Compute SM 5.0, NVENC Available ]

>> InitCUDA() has detected 1 CUDA capable GPU device(s)<<
  [ GPU #0 - < D16P2-30 > has Compute SM 5.0, Available NVENC ]

>> Select GPU #0 - < D16P2-30 > supports SM 5.0 and NVENC
File: src/CNVEncoder.cpp, Line: 1731, nvEncOpenEncodeSessionEx() returned with error 21
Note: GUID key may be invalid or incorrect.  Recommend to upgrade your drivers and obtain a new key
NVENC error at src/CNVEncoder.cpp:1733 code=21(<b>NVENC Feature not available for current license key type</b>) "nvStatus"


Can you please give me some informations where we can get a license key from and if it’s possible to use nvenc with this card? The internet is full of informations with users that have the same problem and nobody knows where to get the license key…

Kind Regards,

Same issue here, used the latest drivers which include GTX750 TI support(334.21), which supposedly has the key “built-in” (according to other forums) - but clearly does not. This issue conflicts with some of the information presented on websites such as - which indicate the NVENC capability of this card as one of the key features. I purchased this first Maxwell generation card with NVENC specifically in mind.
Please provide some feedback as to the reason of this inconsistency ?



I’m not having any problems under Windows 7 SP1 with the WHQL 334.89 drivers…

I just fired up one of my old NVENC-devtool. I’m using Windows 7 SP1 x64, the Geforce WHQL 02/18/2014 drivers (334.89), the CUDA 5.5 release library, and the older Sep 2013 NVENC 3 Beta SDK.

In my sample program, in the call to open the nvenc-session, I set the client_key var to all zeros {0}.

As far as reported abilities, the 750TI reports exactly the same surface-formats (NV12 tiled 64x16) , and nvenc_caps as my Geforce GTX650. I was kind of hoping to finally see the MVC/stereo profile, or the 444 chroma-mode, but alas they are still not exposed (as far as I can tell.)

For the two video resolutions that I’ve tried (1920x1080, 3840x2160), my GTX750TI (GM107) is indeed roughly ~2.0x as fast as my GTX650 (GK107) From what I can tell, on an Maxwell GPU doing nothing else, NVENC can barely exceed 60fps @ 3840x2160 (1 bframe, minQP rate-control.) It will be interesting to see if NVidia enhances the “Shadowplay” recording feature for Maxwell.

Hi nvencnotquicksync,

do you have the drivers also for linux? Anyway, can you give me a link where I can download the beta drivers? It seems with the official drivers that’s not possible anymore… :(

That would be awesome!



interesting, that makes this a pure Linux driver issue (forgot to mention that I am using Linux drivers as well) ?

Than this becomes a more formal request to NVidia to fix their drivers on Linux (also for NVENC ;=), and/or to provide Beta drivers that work on the 750GTX as well. Obviously reverting back to the included drivers (331.x) in the SDK 3.0 is not an option.

Ok i’ve now installed win7 with NVIDIA 335.23 Driver and NVENC 3.0 SDK and it’s running fine without license key and the NVIDIA GTX 750 TI.

For Linux there is only the 334.xx driver available not the 335.xx like for windows and it seems that there is the problem. Linux have to wait for 335.xx driver as far as I can see now…

One problem, does anyone know how to convert a mpeg2 to h264 via nvenc ? I’ve only had success with the YUV sample included in the nvenc sdk but if I try to convert a mpeg2 to h264, the h4264 video picture is like this:

Does anyone know why?!

I’m leaving the NVENC Idea now… tested with QuickSync which produces a much better video quality and is much faster!

330fps in QuickSync vs. 240 FPS in NVENC. Enough said i think… :)