[BUG] NVENC Recording Starts at Low FPS for 30 seconds

[klaxian]

I have been using Bandicam for years to record gameplay at 30fps. Now that YouTube supports 60fps, I want to record my footage at the higher framerate. Unfortunately, the video files recorded by Bandicam using NVENC or CUDA begins at 30fps or less, despite my best efforts. My game is rendering at 100-144fps so I have plenty of headroom. If I select the "Ultrafast setting for 60 fps" preset, I can record at 60fps with motion JPEG from the start. Nvidia's Shadowplay has no problem recording smooth 60fps at 50mbps H.264 on the same games with my setup. After the first 30-45 seconds of footage, 60 frames are finally recorded each second? Earlier parts of my videos have far fewer frames per second.

Settings
Version: Bandicam 2.1.0.708 licensed
Tried both AVI and MP4
Tried "full size" (1440p) and scaling down to 1080p
60fps
Succeeds: Xvid, MPEG-4, Motion JPEG, Nvidia ShadowPlay, x264vfw external codec
Fails: NVENC, CUDA
Quality: 80
Audio: tried PCM and stereo AAC 48khz
Games: World of Warcraft, Middle-earth: Shadow of Mordor
Tried disabling CPU and GPU power saving features like SpeedStep

System
Intel i7 3770K @ 4.5GHz stable
Nvidia GTX 780ti
16GB DDR3 2133MHz CL9
Nvidia Driver 344.60 (tested 344.48 also)
ASUS ROG Swift 1440p screen with G-Sync
Game files on Samsung 840 Evo SSD
Video recorded to separate HDD

[Zuzu_Typ]

Please, Do not use NVENC! NVENC is the worst thing NVIDIA ever made, use CUDA instead, how to use it?
Watch this post: viewtopic.php?f=10&t=2645

[klaxian]

Thank you for the suggestion. I followed the instructions and switched back to CUDA. Unfortunately, videos appear with lower framerates than NVENC. Footage is at about 35fps in my latest test with CUDA. Even if NVENC is bad, it doesn't appear to be the problem in this case. Any other ideas?

[klaxian]

Perhaps this is a GPU acceleration issue in Bandicam. It appears that other codecs like Xvid, MPEG-4, and Motion JPEG that don't use the GPU are able to produce smooth 60fps videos. NVENC and CUDA H.264 produce choppy video files at 35-45fps. I updated the OP with the additional details.

[CamJGaming]

I don't think that Zuzu_Typ knew what he was talking about. NVENC is an onboard h264 encoder that isn't used by games. So it wouldn't affect your fps. What will affect your fps is the encoding settings you are using, such as h264 or x264. It is recommended by Bandicam to use x264 with the following settings for maximum performance.

[Zuzu_Typ]

I do know what I am talking about, but who cares about fps if the output is like 20% worse?
Also NVENC can cause recording problems and also you really don't need 60 FPS, cause your eye is only able to see 24 FPS so 30 FPS is just fine. So 60 FPS does NOT mean 100% performance.
However why did you write this:

NVENC is an onboard h264 encoder that isn't used by games. So it wouldn't affect your fps

???
I mean you just said that it isn't made for games so why did you mention that it wouldn't affect your fps it maybe does not affect your FPS, but it does affect your performance so who doesn't know what he's talking 'bout?

[klaxian]

I may not be explaining this well. However, Zuzu_Typ, you really need to check your facts before you post statements that are clearly false. Human eyes can distinguish more than 24 frames per second. This is not an opinion. It is scientific fact. Look it up.

GPU encoders have been historically worse in quality than their CPU counterparts because GPUs are not well-suited to that task. However, it is up to each individual to determine how much quality they are willing to sacrifice for speed improvement. NVENC should be better in quality because it makes use of a specific hardware H.264 encoder built into recent Nvidia cards instead of trying to use GPU cores to do the rendering.

Those points are not relevant to this post though. To be clear, I am not concerned about my fps in-game because it is always above 100fps. The problem is that the video files that Bandicam creates contain only 35-45fps even though my system has ample power to record 60fps and the games I'm playing are always well above that framerate. Only GPU-accelerated codecs like NVENC and CUDA are affected. This seems like a bug in Bandicam related to their use of nvidia GPU acceleration technologies like NVENC, but I wanted to check with the community to make sure I'm not missing something.

If you don't have any other ideas, where is the best place to report the bug? Thanks!

[Dfactor]

I do know what I am talking about, but who cares about fps if the output is like 20% worse?
Also NVENC can cause recording problems and also you really don't need 60 FPS, cause your eye is only able to see 24 FPS so 30 FPS is just fine. So 60 FPS does NOT mean 100% performance.
However why did you write this:

NVENC is an onboard h264 encoder that isn't used by games. So it wouldn't affect your fps

???
I mean you just said that it isn't made for games so why did you mention that it wouldn't affect your fps it maybe does not affect your FPS, but it does affect your performance so who doesn't know what he's talking 'bout?

1) NVENC is meant for capturing videos and is currently the best way to capture anything (with Nvidia cards)
2) Human eye does not see the world in "FPS". Please do some more research before trying to prove something.
3) Due to language barrier you interpret things completely wrong.
4) He said that NVENC utilizes the part of GPU that isn't in use while the game is running, thus not affecting game's performance. (True, but not completely)

@klaxian
Did you use VBR? What's the keyframe? The quality doesn't work that well, better keep it on 100q.
Also keep the Full Size. Do you have any forced options on those games? As in Nvidia control panel > Adjust image settings with preview. Should be "Let the 3D application decide."
Is it possible to disable G-Sync and check if there's a difference?
In any case it seems like some compatibility issue. I've been using 1080p/1440p 60fps NVENC for quite a while now.

[klaxian]

Thanks for the response! Yes, I use VBR. I tested with "full size" and downscaling to 1080p. There was no difference. There are no forced options in the Nvidia control panel except G-sync. I will disable G-sync and try your other suggestions to test. Much appreciated.

[klaxian]

Thanks again for the suggestions. However, the following things failed to solve the issue or produce any change whatsoever:

1. Disabled G-sync
2. Disabled MSI Afterburner
3. Set quality to 100
4. Recorded at "full size"
5. Set all Nvidia control panel settings to defaults
6. Forced GPU maximum performance with Nvidia control panel
7. Tried keyframes 60, 120, 150

In my tests, my game is always running at over 100fps while recording. However, the video file produced by Bandicam contains about 39fps with some stutter. This is not a playback problem. The video simply doesn't contain enough frames for 60fps when I use NVENC or CUDA. Other codecs work fine. Nvidia's ShadowPlay records smooth 60fps video at 50mbps and presumably uses the same NVENC API. It seems like there is a bug in Bandicam or something in Bandicam is bottlenecking the application. How can I report the bug?