Showing posts with label NVIDIA. Show all posts
Showing posts with label NVIDIA. Show all posts

Thursday, 22 May 2014

Using the EVGA Nvidia GTX 780 6GB graphics card with DaVinci Resolve


Thought I would offer some feedback on the new Nvidia GTX 780 with 6GB of GPU RAM (double the original card). The gaming community weren't too enthusiastic about this card saying that the extra RAM would have no effect on game play, but looking at the demands of DaVinci it seemed like the extra RAM would help. Unusually I became an early adopter and bought the EVGA branded card from Overclockers when it was released. Here are my findings.

Prior to installing the new card I had an Nvidia GTX 570 (1.28GB) with an old Nvidia Quadro card. I have a Windows i7 3.6GHz processor with an Asus P9X79 motherboard (not the Pro) and 32GB of RAM, so not a slow machine. 

With this setup HD playback was fine until I added NR or sharpen when playback was 1 or 2 frames per second. As soon as I changed the project settings to UHD the screen filled with shash and I got the message that I was out of memory. I could render out in 4K but it was slow and I could not see the results processing.

With the GTX780 installed in PCIEX16 slot 1 and the GTX 570 in slot 2. Thanks to a tweet form @rohit_bmd I tried removing the GTX570 as he suggested this card may slow things down. He was right and all speeds have increased by 2-3 fps with just the GTX 780 in place.


The result:
In Media and Edit modes the 4K (well UHD) footage from the BMPC plays back at 21 - 23 fps and audio is smooth. This is only on a 1920x1080 computer monitor - I don't have an external 4K monitor yet. 

In Color mode even without adding any grading, NR or sharpening the playback occurs in bursts with a slight pause (less than a second) between each one. DaVinci reports that playback speed is varying between 10fps and 13fps. Adding sharpen lowers this rate to 8-10 fps. Not ideal but at least I can see what the effect the colour correction on a full 4K image. For noise reduction this makes a big difference. I have not received any out of memory pop-ups.

Delivery (rendering) is very quick and I can now see the pictures as they are processed.

The computer RAM is barely being troubled by Resolve and 16GB would be more than enough but the CPU peaks at around 75% usage on playback so a fast processor is recommended. 

An added bonus of the new card is the speed of After Effects which is loving the massive CUDA core boost. 

Conclusion: For the money I think this is an excellent upgrade for DaVinci if you are wanting to work with 4K footage. It surpasses what would be expected from the DaVinci configuration guide from this setup. I think that if I added another GTX 780 6GB card I would be close to running at 25fps in Color mode.

Hope this helps others looking at buying this card. EVGA are offering a step-up if you have an older EVGA card.

Tuesday, 25 March 2014

The Blackmagic Production Camera 4K experience Part 2

In part 1 of this blog I documented the first experiences of using the Blackmagic Design Production Camera (BMPC) and how I chose the SanDisk Extreme II 240GB SSDs, a cheap battery solution and a low priced EVF monitor. So far this setup has cost £2310 for the camera, nothing for the battery system (OK about £16 if you bought it), £260 for 2 SSD cards and £400 for the Cineroid EVF-4CSS a total of £2986 (or €3577 or $4936). To this I have to add a tripod and of course suitable Canon lenses which can easily double the price.

But as a result I have a rig capable of shooting 4K pictures on a good codec (ProRes at the moment) with a global shutter (so no "jello") and I have a piece of software that would cost $995 if bought separately, more about this later. But the usability of the BMPC is always an issue and the form factor of the camera worried me because it is heavy and, I predict, easy to drop. I also needed something to attach the EVF and an external microphone. 

I had looked at a lot of cages but the cheap ones were, well cheap, and all of them were bulky and meant I couldn't fit all the kit in my brilliant Lowepro Stealth Reporter D550AW bag. My solution is from Redrock Micro with a top handle and the Ultraplate which added about £100 to the total. The Ultraplate offers just enough screw points to attach the handle, the EVF on a mini magic arm and a mic or recorder if needed.





So the whole rig looks like this.




Post Production

So I have shot the footage, got (most of) it in focus thanks to the EVF and now I need to edit it and Blackmagic Design have kindly included a copy of DaVinci Resolve 10 with a USB key in the BMPC box to help me. This is the first time I have tried to work with 4K footage and I have a pretty powerful PC to do so with i7 processor, 32 GB RAM, Nvidia GeForce GTX 570 and Quadro FX580 graphics cards. Unfortunately this is far to weak to properly edit 4K footage and as I don't have a 4K monitor I can either view the footage in HD or just see the top half of the footage spread over two 1920 monitors. 

It's not brilliant but it is possible to work this way and produce great results. I work mainly with Avid Media Composer which is less than useless for 4K or Adobe After Effects which is more than good but Resolve is like neither of these and if you are going to use it properly will take fair bit of learning  - persevere it is well worth it. This is not a tutorial in Resolve so I just want to highlight some of the Eureka moments I have had so far. 

Where you store your footage for editing is really important, run the included Blackmagic Disk Speed Test on all your drives and put the material on the fastest one - you can archive to a slower drive later. A raid drive such as the G-Raid is likely to be the best, better than the fast SSD (that was a surprise). 

Unless you have a monster $1000+ GPU like the GTX690 or NVIDIA Titan you will not be able to play 4K on your timeline, you will get a screen of shash and a GPU out of memory message. Go to project settings and select 1920x1080 as your timeline resolution. 

THIS IS IMPORTANT. When you have finished editing and grading and you go to the "delivery" window and select UHD as your output you have to go back into project settings and set the timeline to UHD, if you don't your final output will be HD expanded to fit the UHD raster. Resolve is actually very good at this and it took a lot of looking to see the difference. Below is a still from a scene in Trafalgar Square and two crops with the timeline set to different resolutions. The middle picture shows the image at 400% with the timeline set to UHD and the bottom picture with it set to HD. The bottom picture shows a lot less detail.









If you look at the comparison table of Resolve lite and the full version there doesn't seem to be a lot of difference, but go about a third of the way down and you will see this section:



After the sharpening tool (like the 5D the images generally benefit from a bit of sharpening) the noise reduction tools make a huge difference particularly in areas like sky or flesh tones, be gentle with it and you will be rewarded. The BMPC is not good at shooting in low light (and I am not a fan of ProRes for this) and sometimes scenes like the one below in St Pancras Station mean lifting the dark areas considerably which can bring in really bad speckle. The noise reduction tool in Resolve is amazing at reducing this.




The format you output will always depend on where you will put it, but I have established a workflow from producing 4K time lapses where I output QuickTime Cineform versions which are indistinguishable from uncompressed files but much smaller and then use Adobe Media Encoder to produce QuickTime PhotoJPEG versions for stock companies or broadcasters since that is such a user friendly format and one that Resolve cannot output directly. 


These two blogs have been a quick summary of what I have learnt "hands-on" with this amazing camera and what I feel is the minimum requirement to shoot good footage. Hopefully it will give a bit of guidance to those still in the queue for the 4K Production Camera.