Severe lag when cutting or moving clips in VEGAS Pro 23 (4K 25fps)

Cyrielle wrote on 11/7/2025, 9:47 AM

Hello,

I’m experiencing a major issue with VEGAS Pro 23 while derushing my footage.
Every time I make a cut on the timeline, there’s a 2–3 second delay before the action is registered.
The same thing happens when I try to move or join two clips together. I always have to wait several seconds before VEGAS reacts.

I want to make it clear that preview playback is perfectly smooth, with no lag at all.
The problem occurs only when interacting with the timeline cutting, trimming, or moving clips becomes extremely slow and makes it almost impossible to work efficiently.

This issue happens only with my 4K 25fps files, and it makes derushing practically unusable.
I’m honestly considering reinstalling VEGAS Pro 16 just to do my rough cuts and then returning to Pro 23 for the final edit, because right now, it’s impossible to work this way.

Here are a few details about my setup:

Footage: 4K, 25 fps

GPU: NVIDIA RTX 5090

RAM: 64 GB

Proxy files: created and enabled

GPU acceleration: “Optimal NVIDIA RTX 5090”

I’ve attached a short video demonstration to show you exactly how slow and unusable the editing process becomes when I try to cut or move clips.

Do you have any idea what could be causing these timeline slowdowns, or any settings I could adjust to make cutting and moving clips more responsive?

Thank you very much in advance for your time and help.

Comments

andyrpsmith wrote on 11/7/2025, 10:36 AM

Two quick questions, what is your media and what happens if you unselect all your FX's? I found that certain sound FX's would cause this both with V22 and V23 when more than one FX was used. The delay increased with each FX added.

Cyrielle wrote on 11/7/2025, 10:46 AM

Thx you for reply Andy

My media files are recorded in Sony XAVC-S (AVC) format, 3840x2160, 25 fps (PAL), with progressive scan and limited color range.

I haven’t applied any FX at all not even the default ones. The project is completely clean, but the lag still occurs every time I cut, move, or paste clips on the timeline.

john_dennis wrote on 11/7/2025, 11:05 AM

@Cyrielle said: "My media files are recorded in Sony XAVC-S (AVC) format, 3840x2160, 25 fps (PAL), with progressive scan and limited color range."

Which camera are you using?

Why is your audio track mono?

Is the audio from another source?

andyrpsmith wrote on 11/7/2025, 11:10 AM

Your sound track shows an FX with a blue dot indicating an FX has been applied. I use the same media with no issues unless I add specific sound FX to reduce wind noise.

john_dennis wrote on 11/7/2025, 11:23 AM

@Cyrielle Please use this link: (FAQ) How to post MediaInfo and VEGAS Pro File Properties to tell us about the media on your timeline.

Also, give us a screenshot of your Project Properties panel.

Cyrielle wrote on 11/7/2025, 11:59 AM

@Cyrielle said: "My media files are recorded in Sony XAVC-S (AVC) format, 3840x2160, 25 fps (PAL), with progressive scan and limited color range."

Which camera are you using?

Why is your audio track mono?

Is the audio from another source?

Hi John,

I’m filming with a Sony A7 IV camera.

You’re right, the audio comes from an external recorder, a Zoom F3, which is why it’s in mono.

I’ll provide the MediaInfo details and a screenshot of my Project Properties panel as you requested.

Cyrielle wrote on 11/7/2025, 12:03 PM

Général
Nom complet                              : C:\YOUTUBE\TELEGRAM ENQUETE\PARTIE 1.MP4
Format                                   : XAVC
Identifiant du codec                     : XAVC (XAVC/mp42/iso6)
Taille du fichier                        : 19,6 Gio
Durée                                    : 27 min 25 s
Type de débit global                     : Variable
Débit global                             : 102 Mb/s
Débit im/s                               : 25,000 im/s
Date d'encodage                          : 2025-10-31 13:07:52 UTC
Date de marquage                         : 2025-10-31 13:07:52 UTC

Vidéo
ID                                       : 1
Format                                   : AVC
Format/Infos                             : Advanced Video Codec
Format, Profil                           : High@L5.1
Paramètres du format                     : CABAC / 2 Ref Frames
Paramètres du format, CABAC              : Oui
Paramètres du format, Recadrer           : 2 images
Identifiant du codec                     : avc1
Identifiant du codec/Infos               : Advanced Video Coding
Durée                                    : 27 min 25 s
Type de débit                            : Variable
Débit                                    : 96,8 Mb/s
Débit maximum                            : 100,0 Mb/s
Largeur                                  : 3 840 pixels
Hauteur                                  : 2 160 pixels
Facteur de forme l/h                     : 16/9
Type de débit im/s                       : Débit im/s constant
Débit im/s                               : 25,000 im/s
Espace de couleurs                       : YUV
Sous-échantillonnage de la chrominance   : 4:2:0
Profondeur binaire                       : 8 bits
Type de balayage                         : Progressif
Bits/(Pixel*Image)                       : 0.467
Taille du flux                           : 18,5 Gio (95%)
Bibliothèque utilisée                    : AVC Coding
Date d'encodage                          : 2025-10-31 13:07:52 UTC
Date de marquage                         : 2025-10-31 13:07:52 UTC
Gamme de couleurs                        : Limited
Coordonnées de chromaticité              : BT.709
Caractéristiques du transfert            : BT.709
Coefficients de la matrice               : BT.709
Metas                                    : 3
Erreurs de conformité                    : 1
 AVC                                     : Yes
  Conformité générale                    : Bitstream parsing ran out of data to read before the end of the syntax was reached, most probably the bitstream is malformed (frame [0..3428], time [-00:00:00.040..00:02:17.069], offset [0x7AEDF..0x4E537C362])
Configuration des codecs                 : avcC

Audio
ID                                       : 2
Format                                   : PCM
Paramètres du format                     : Big / Signed
Identifiant du codec                     : twos
Durée                                    : 27 min 25 s
Type de débit                            : Constant
Débit                                    : 1 536 kb/s
Canal(aux)                               : 2 canaux
Échantillonnage                          : 48,0 kHz
Profondeur binaire                       : 16 bits
Taille du flux                           : 301 Mio (1%)
Date d'encodage                          : 2025-10-31 13:07:52 UTC
Date de marquage                         : 2025-10-31 13:07:52 UTC

Autre
ID                                       : 3
Type                                     : meta
Format                                   : Sony Real Time Metadata
Identifiant du codec                     : rtmd
Durée                                    : 27 min 25 s
Type de débit                            : Constant
Code temporel de la première image       : 10:49:02:10
Taille du flux                           : 763 Mio (4%)
Date d'encodage                          : 2025-10-31 13:07:52 UTC
Date de marquage                         : 2025-10-31 13:07:52 UTC
TransferCharacteristics_FirstFrame       : BT.709
ColorPrimaries_FirstFrame                : BT.709
MatrixCoefficients_FirstFrame            : BT.709
IrisFNumber_FirstFrame                   : 1.601928
FocusPositionFromImagePlane_FirstFrame   : 0.788 m
LensZoom35mmStillCameraEquivalent_FirstF : 25.200 mm
LensZoomActualFocalLength_FirstFrame     : 24.000 mm
FocusRingPosition_FirstFrame             : 78.2471%
AutoExposureMode_FirstFrame              : Manual
AutoFocusSensingAreaSetting_FirstFrame   : Full Screen Sensing Auto
ImageSensorDimensionEffectiveWidth_First : 35.880 mm
ImageSensorDimensionEffectiveHeight_Firs : 20.183 mm
CaptureFrameRate_FirstFrame              : 25.000 fps
ShutterSpeed_Angle_FirstFrame            : 177.5°
ShutterSpeed_Time_FirstFrame             : 1/51 s
CameraMasterGainAdjustment_FirstFrame    : 0.00 dB
ISOSensitivity_FirstFrame                : 100
ElectricalExtenderMagnification_FirstFra : 100%
AutoWhiteBalanceMode_FirstFrame          : Preset
ExposureIndexofPhotoMeter_FirstFrame     : 100

Cyrielle wrote on 11/7/2025, 12:07 PM

Ah, you’re right. I hadn’t noticed, I actually had three audio FX applied on the sound track.
But after unchecking them and testing again (cutting or doing actions on the part where I removed the FX), it’s still the same the lag is still there.