RAM & CPU % usage generating optimized media in DaVinci Resolve

[Michael Gissing]

Resolve is GPU intensive so you need to look at what the GPU is doing during a render not just the CPU. Unusual choice of codec for optimised media. A 444 HDR codec is complete overkill for GH4 files. It maybe that with a big fat file like that the hard drive was a bottle neck.

The GTX 970 is a bit underpowered and take note that as Resolve moves into version 14 that it specifies Kepler NVIDIA cards. 4k files do better with a graphics card with at least 8 gig of onboard graphics RAM. So that and possibly the hard drive were slowing the render.

[Kevin Ollivier]

Thank you for your time Michael,

I don’t know if rendering is the same than “generating optimised media”:

– when I render the same kind of h.264 clips with gradation and effects, I can see my CPU used at approx. 85-95% and the GPU between 55-75%, which I think is correct.
– when I generate optimised media, the GPU isn’t used more than 10-12% and the CPU at max. 40%

I choose DNxHR 444 HDR for optimised media because it takes less space on my 7200rpm hard drive than “uncompressed-10 bits”.
If there is another codec that I should use with the GH4 files, I happy to learn!

I’m running DaVinci Resolve 14 on my 128gb SSD, maybe I should go back to 12.5 to benefit my gtx 970m and optimise overall performances?

Again, thanks

Kevin

NOTE: both files for optimised media and rendering go to the HDD, not on the SSD

msi gs60 6qe
CPU: i7-6700HQ @2.60GHz
ram: 16gb
GPU: gtx 970m 6gb
windows 10
DaVinci Resolve 14

[Kevin Ollivier]

Many tests done:

– cache files location from HDD to SSD and back
– rushes location from HDD to SSD and back
– generating optimised media and rendering to HDD and to SSD

I think you’re right Michael, it seems that the 7200 rpm HDD is a bottleneck! Disc activity shows 88-100% while generating on it.
When cache files are on the SSD, generating optimised media uses the processor up to 95% of its capacities, SSD activity is around 13%, and waiting is at least twice less than with the cache files on the HDD.

I think I’ll use the usb-c 3.1 port to plug a brand new big SSD for my cache files!

I’m still interested in some advice about the different codecs to use with gh4 files, and in which case to use it best.

Thanks again, I think the main issue is solved.

Kevin

msi gs60 6qe
CPU: i7-6700HQ @2.60GHz
ram: 16gb
GPU: gtx 970m 6gb
windows 10
DaVinci Resolve 14

[Ole Kristiansen]

Hi

You can download BlackMagic Disc Speed test !

best,
Ole

[Kevin Ollivier]

Thanks Ole, hard to find for windows but I finally got the speed test, I’m not sure how to read it… this is what it says about my 7200HDD

[Ole Kristiansen]

Hi Kevin

Here is how to read it

[Ole Kristiansen]

I have my video footage on a software raid 0 disc consisting of 2 Samsung SSD 850 EVO! Have the opportunity to add an extra Samsung SSD 850 EVO – for more speed! My media cache drive is also a Samsung SSD 850 EVO!

Here is the speed of my raid 0 disc

[Kevin Ollivier]

That is a fast system….

Regarding the kind of codec to use for optimised media for gh4 files, I will search furthermore about it. I shoot internally, so 422 8 bit if I’m correct… uncompressed codecs seems to create way too large files.

Thanks for your advices.

Kevin

msi gs60 6qe
CPU: i7-6700HQ @2.60GHz
ram: 16gb
GPU: gtx 970m 6gb
windows 10
DaVinci Resolve 14