When I edit a clip, it takes every now and then a couple of seconds to load the clip during playback, which looks like lag in the recording, but which is just on Lightworks end.

Not to mention transition, which load so slowly that the playback progress just skips it and moves on with a frozen frame a few seconds before.

Is there a setting that can store a part of the clip in memory to smoothe out the playback?

Here are my laptop specs:

Dell Vostro 5568

Processor: Intel(R) Core(TM) i7-7500 CPU @ 2.70GHz 2.90 GHz
Installed memory (RAM): 16.0 GB
System type: 64-bit Operating System
Display adapters:

Intel(R) HD Graphics 620
32-Bit
128 MB Dedicated Video Memory

NVIDIA GeForce 940MX
64-Bit
4096 MB Dedicated Video Memory

Simple answer, no.

With the Pro version there's a feature called "Time Line Rendering" to render complex parts of an edit to hard drive to improve performance.

I assume, depending on the format of your footage, converting prior to import might bring significant acceleration. To find out what's best for you a mediainfo report of a file you typically use for editing would be helpful, please see:

www.lwks.com/index.php?option=com_kunena&func=view&catid=23&id=66072&Itemid=81

I assume you are on Windowsw 10 and you use your NVIDIA graphics with onboard Intel graphics disabled.

Thank you for your reply, hugly!

Oh, right, I am using Windows 10 and as for disabling the onboard intel graphics, I believe I have set Lightworks to "High performance NVIDIA processor" in NVIDIA Control Panel. I used the path:
c:\program files\lightworks\ntcardvt.exe (is this the path for Lightworks x64?)

My recordings are in mp4 format, and I always export with the Youtube settings on 30 fps and 720p.

Thank you for letting me know about MediaInfo! Is there any particular settings that I should be aware of to accommodate my normal export setup?

No, if your recordings are at 30fps that's all you can do.

MP4 is a container and may wrap different video and audio formats. I assume that you use the most common long GOP AVC-video with AAC-audio.

If that's the case you're using a format very demanding to decode for a NLE. It's good for streaming, but not for editing. Sometimes AVC video comes with variable frame rate which can cause sync issues between audio and video and has to be converted anyway (detectable with Mediainfo).

To improve overall editing performance and to avoid sync issues you should transcode your footage to an edit friendly intermediate format prior to import into Lightworks. Personally I use frequently MPEG2 I-Frame HD video with MP2 audio also wrapped into a MP4 container. If you wish to give it a try, you will find a suitable procedure here.

Alright, I'll give your settings on EyeFrame a try. Thank you very much!

Lightworks decodes and buffers compressed video to ram up to the limits of ram capacity by default. The bottleneck in your case is the CPU which handles decoding. The GPU renders decoded video to the screen.
MP4 compressed video at low bit rates is very processing intensive to decode.
If you are using your internal system drive to store your media, that to will slow things down. Add a dedicated external USB3 drive to speed things up. Does your laptop have USB3 ports (blue color)?
Transcoding to a DI format like Prores or Cineform speeds things up significantly. I use Cineform.
The free GoPro software app includes GoPro Studio which can import and transcode .MP4 videos to any of five different Cineform quality levels. File sizes will get much larger, but the processing overhead is much lighter.
Short comparison demo of a 1080p .mp4 from my iPad and the same clip in Cineform Hi:

the idea of Erlend1 is correct, if you use fusion you can add pcs to let them prerender near the playhead, so when the playhead is stopped lwks could buffer a few frames to the end for the active window ...

(of course this could be a config settings, how much to buffer, only to the end or also to the beginning, ... etc or "off" if you have less gigabytes ram free)
greets
simon

so this could be a thing of the past ...

"it's onyl fullHD"

www.dma.ufg.ac.at/assets/24933/intern/buffered_playhead_position_s.mp4

s.

Filling additional buffers may cause also playback delay. The basic dilemma of an NLE is that it doesn't know what the next play direction or jump location is. I don't know if LW has the best dynamic buffering system of the world, but it's not bad in my view. I believe that a normal user wouldn't be able to decide what's best buffer size.

The proxy functionality in the future Lightworks 14 version would be another option.
Provided that the 240p playback quality is sufficient for your purposes.

@hugly: it's just to don't have the "press play delay" by buffering.
if I stop and start again (as seen in the video) the pause should be gone.
the buffer could be auto set relating to project settings, if needed.
greets
simon

@schrauber: proxy is fine, but at the moment not very flexible in proxy-resolution as you said.
if you haven't time to generate proxes and just need a few parts of the video the buffer would reallly help.
of course scrubbing is not a thing the buffer can solve.

greets
simon

I didn't catch this meaning from the above.

Yes, I agree, to get rid of this kind of startup delay seems possible.

Maybe you should place this into a newly created topic in beta forums?

[quote="hugly" post=133081]

hi, yes I just ment that start delay with the statement above.
probably there are other areas where such a buffer could help.
greets
simon

LW has been wrangling 'buffering' for more than twenty-five years - seems to me they are pretty expert at it. There was a time custom buffering settings could be entered in config.dat but (a) Can't recall anyone arriving at anything better than the default (b) that was in the days of 64Mb RAM capacity

no, no, please don't prebuffer 25 years, even I'd so much ram ,-)

@topic. it's the same on a pc with more ram + xeons, but still there is the lag by pressing play.

simon