4k/2k 30/60fps Write Speed Requirements & File Size Estimate?

[nocktwice]

Having a bit of trouble finding info for 4k/2k write speeds & estimated file sizes for recording. Mainly because I don't have a 4k or 2k monitor & would like the opinions of those who do what their experiences are when recording at these resolutions, using these codecs: UTvideo, MagicYUV, Lagarith, Matrox in 420 colorspace. If the codec you use is not listed feel free to share them please!

I'm currently using UTvideo 420 BT709 (64bit) settings to record my 1080p (1920x1080) gameplays. I get around 300gb+ for a little over 2.5 hrs of gameplay with Far Cry Primal on very high settings (not even ultra) which is massive. But considering 4k/2k that would be much, much bigger lol.

Also what drives do you use? Do you use HDD or SSD for 4k/2k?

[chronosek]

some disk transfer for loseless codecs you can find in this old thread: http://forum.exkode.com/index.php?topic=1790.0

[ClassifyLP]

If you have an Nvidia card you can use the DSR setting. That's how I record in 1440p even though I only have a 1080p monitor.

I get around 90MB/s in Skyrim (1440p @ 30fps MagicYUV 4:2:0 YUV). Got around 170MB/s in Mirror's Edge (1440p @ 60fps, same settings).

You can generally say that fps scale linear (double the fps, double the transfer rate) and resolution on ones axis does the same, while total resolution scales exponentially (e.g. "double" from 1080p to 2160p, quadrouple the transfer rate).

I'd recommend a RAID 0 of at least two HDDs for anything above 1440p. Do not use SSDs for recording, they'll wear out pretty fast unless you get the enterprise ones.

[nocktwice]

If you have an Nvidia card you can use the DSR setting. That's how I record in 1440p even though I only have a 1080p monitor.

This is a good tip! Will try this out see if there's any quality difference when recording in 2560x1440
Only problem is now all the text is blurry.

some disk transfer for loseless codecs you can find in this old thread: http://forum.exkode.com/index.php?topic=1790.0

Are these still accurate? I ask because the last edit was february this year (2016). Thx

[chronosek]

Are these still accurate?

I think it is still acurate, cause it depends only on codec method compression

[ClassifyLP]

This is a good tip! Will try this out see if there's any quality difference when recording in 2560x1440
Only problem is now all the text is blurry.

There is a DSR smoothing setting, set it lower if you think it is too blurry. I have mine on 25%.
Also, the recording will always be sharp, no matter what.

[nocktwice]

There's a buggy invisible wall in games where my cursor cant go passed when I use the DSR settings. But apart from that the quality difference is noticeable especially on exports. The write speeds is def too much for my current 7200 rpm drive. There's also a considerable impact to FPS too with DSR. And the blurryness only exists in windows. Once I go full screen in games its fine.

Now the question is DSR result the same quality & performance as an actual 2k monitor?

[nocktwice]

Are these still accurate?

I think it is still acurate, cause it depends only on codec method compression

Cool. Those transfer speeds look optimistically low. According to that sheet, a 1hr recording of 4k gameplay using utvideo 420 bt 709 with 130mb/s gives about a total 468gb file size. Times that by 2.5hrs & we get 1.17tb file size in comparison to my 1080p recording. Which is around 67% more than what my 1080p records. I hope that math is right lols. But wow what a difference. I take optimistic back.

How do people do it with 4k gameplay recording? What kind of HDDs are even capable of 4k recording? I can only imagine the cost it takes to build a full 4k gaming pc.

[ClassifyLP]

There's a buggy invisible wall in games where my cursor cant go passed when I use the DSR settings. But apart from that the quality difference is noticeable especially on exports. The write speeds is def too much for my current 7200 rpm drive. There's also a considerable impact to FPS too with DSR. And the blurryness only exists in windows. Once I go full screen in games its fine.

Now the question is DSR result the same quality & performance as an actual 2k monitor?

That should not happen, but you are not supposed to actually use DSR outside of a game anyway. And yes, it will impact game performance and encode perfomance, since the game runs at a higher resolution (it's a similar effect to anti-aliasing, so turn that off when using DSR).

The quality of the recording will be the exact same as if it was your monitor's native resolution, since Dxtory records before the scaling back to your native resolution happens.

Cool. Those transfer speeds look optimistically low. According to that sheet, a 1hr recording of 4k gameplay using utvideo 420 bt 709 with 130mb/s gives about a total 468gb file size. Times that by 2.5hrs & we get 1.17tb file size in comparison to my 1080p recording. Which is around 67% more than what my 1080p records. I hope that math is right lols. But wow what a difference. I take optimistic back.

How do people do it with 4k gameplay recording? What kind of HDDs are even capable of 4k recording? I can only imagine the cost it takes to build a full 4k gaming pc.

It's important to note that scene complexity (2D level) determines the bandwidth needed. A completely black screen might only take a tenth of a multi-colored, complex environment (e.g. an autumn forrest). That's due to how the codec manages to compress without losing quality.

Multiple HDDs bound together  by a RAID 0 (or similar technology). Dxtory also supports split recording, so you don't have to make a RAID, but you will have to record RAW and stitch the files together, which takes time.
A good HDD (I use a 2TB Western Digital Black) can have write speeds in the 150-200MB/s. It will be difficult to capture 4K with a single drive, but a RAID 0 of two will certainly be enough. However, you might be limited by the CPU and/or GPU at that point.

[nocktwice]

Yea I figured if you were roaming in a gfx intensive area with complex scenery that this would affect the transfer speeds heavily of the recording. I'll try DSR again with 2560x1440 res. I'm testing this with Far Cry Primal. This is the game I experienced those invisable unpassable walls. Should I reboot OS everytime I choose a DSR resolution? Or not required?

From what I can fathom with these 2k/4k gaming pcs, it must cost a fortune especially if you're building it specifically for recording gameplays. Gaming alone you'd just need the most recent gaming competitive CPU & GPU specs including enough RAM to run any one game without any crash interruptions. I know. Heavily generalising there. But the comparison between a pure gaming pc to a gaming + recording PC in cost is a huge gap in price. Like wow. The standard today in youtube from what I can see is 1080p 30fps. I rarely see a 2k or 4k youtuber. Maybe I'm not looking hard enough. But I guess the era of 4k streaming in youtube isn't here yet considering how much it costs to build a damn good PC for that very purpose.

Update on DSR attempt #2: Yep the invisable wall bug is gone. I guess something worked better the second time around.

[chronosek]

it must cost a fortune especially if you're building it specifically for recording gameplays

Profesional YouTuber use external 4k recorder, so they need pc what is only able to play in 4k...