QUESTIONS ABOUT EDITING SUPERPC

Hi,
I have always used Apple Computer for my editing.
After some years witrh FINALCUT 7 I begun to use Da Vinci Resolve and actually it is my preferred Editing system by far. My present gears are an IMAC 27 2014 and a Powerbook 2012.
As I'd like to begin to edit 4K footages I do need to increase the power of my gears.
The logical solution could have been to buy the new Powermac but it is too much expensive to me and not personalizable as I'd like
So I have dediced to build a SUPERPC to solve the problem with less money. I have understood what I need about RAM and harddisks but noy about CPUs and GPUs
I have some questions I'm not able to solve so I ask your help as more skilled users.
Here the questions:
1) As DaVinci uses more GPU than CPU (as I have undestood) is it better for me to buy powerfull GPU then a powerfull CPU? in particular is it better to buy 2 GPUS ( my choise is GEFORCE GTX 1080) to run parrallel computing in order to have the best result possible in terms of speedy and performances?
2) Is it better to run WINDOWS 10 or LINUX to have better performances?
3) As Quicktime is no longer supported under windows have I to have problems with .mov files under WIN10?

Let me know
Thank for your support

Unless you have the expensive panel for the Linux version then you can't use Resolve in Linux as it will only work with the expensive panel.

QuickTime still works fine under Windows 10 just don't install the player or web plug-in components.

The latest version of Resolve shouldn't need QuickTime, although it depends on what's inside the .mov files as .mov is just a wrapper and can contain any number of different codecs inside.

Again, depending on what is in the files depends on how powerful a CPU you need. If they are h264 based then you will need a powerful CPU to decode the footage, especially if you want to decode multiple streams at the same time, then you will need powerful GPU's for the real-time playback, so if possible 2 GTX 1080's would be good

Unless you have the expensive panel for the Linux version then you can't use Resolve in Linux as it will only work with the expensive panel.

QuickTime still works fine under Windows 10 just don't install the player or web plug-in components.

The latest version of Resolve shouldn't need QuickTime, although it depends on what's inside the .mov files as .mov is just a wrapper and can contain any number of different codecs inside.

Again, depending on what is in the files depends on how powerful a CPU you need. If they are h264 based then you will need a powerful CPU to decode the footage, especially if you want to decode multiple streams at the same time, then you will need powerful GPU's for the real-time playback, so if possible 2 GTX 1080's would be good

Adam what do you mean as "Expensive panel" with Linux? I dont understand
I'd wait for the new GTX 1081 due to be shown at CES
Follwing your suggestions the best could be 2 GTX
Is the CPU not a problem or do I need some particular one?
my problem resides in rendering I see a lot of time with my long footages, for it do I need CPU power or GPU power?
let me know

Resolve for linux only comes with the big control panel, and that's 29995 usd.
Free Resolve and the Resolve Studio come only for windows and mac.

Nobody knows the ideal CPU/GPU combination -- or if BMD knows, they're not saying -- but for a new system you would probably want a CPU with a minimum of 6-cores, and possibly 8, 12 or more, depending on your needs. This could mean an i7-5930K or an i7-5960X with the x99 chipset at the lower end, all the way up to dual-xeon CPUs with a total of 28 cores. If you want to consider a used machine, HP workstations with dual xeons tend to be good buys.

But at what point CPU power goes to waste remains an open question....

Look at the Resolve configuration guide. It goes over this material. Buying a system doesn't have to be guesswork.

The Haswell-e i7-5xxx range were superseded by the Broadwell-E i7-6xxx range earlier this year which now gives up to a 10 core, and the Xeon E5-2600 V4 CPU's now go up to 22 cores each, so you could go up to 44 physical cores with 44 hyper-threaded cores, although I'm not sure if Resolve sees above 64 cores or if they have since fixed that.

As to the guide, it's OK for a basic look at things, but doesn't go into good detail and most of the hardware is outdated

Based on what I've observed here, you want to focus on having not just enough GPU power, but also enough GPU RAM! 8GB is probably OK for 4K editing, but one user here seems to be starting to struggle with his 8GB card using all available VRAM with his 4K projects. So 12 GB might be better future proofing. If running two cards, it is best that they be matched in type and RAM capacity. Maybe a single 1080 GTX Ti with 12 GB is the way to go?

CPU seems to generally be less of an issue than GPU. CPU is used primarily for decoding and encoding footage. So if you do a lot of long projects that require a lot of encoding, then you might want to add power here. But for normal decoding of timeline footage, it seems like any reasonably powerful modern 6-10 core or better CPU will be adequate. My personal inclination would be to lean more toward higher clock speeds than extra cores. My thinking is that one of the toughest timeline decoding tasks is h.264 footage, and Resolve's decoding does not scale well with core count. It cannot come even close to saturating 12 Xeon cores. So it is probably better to have the fewer cores that do get spawned operating in the 4Ghz range rather than the 3Ghz range if you think you may want to use h.264 sources without intermediaries from time to time.

BTW, the many comments I've read here about possible Windows 7 inefficiencies while decoding h.264 prompted me to upgrade my home box to Win 10. My initial experience is that Resolve is marginally worse at decoding h.264 under Win 10 - not better.

h.264 editing will probably be problematic with Resolve for at least the near future. That means using a good intermediary or even more data dense format (raw) for footage that will more likely stress a drive than the CPU. So you probably want to make sure you have some really fast hard drives and plenty of space. I'm thinking SSD and perhaps SSD drives in RAID configurations.

"My thinking is that one of the toughest timeline decoding tasks is h.264 footage, and Resolve's decoding does not scale well with core count."

Q1: With the i7 6700 chip supporting 2190p h.264 decode and encode I was thinking Resolve would take advantage of the i7 chip's hardware when working with h.264. Does it?

Q2: I also thought h.264 decode and encode would be passed to a GPU board like the GTX 970 > GTX 1080 because I assumed they would be very fast at doing the decode and encode. Does it?

If both answers are "no" then the CPU cores are used -- so when you say "decoding does not scale well with core count" where is tipping point? There are reasonably priced Haswell 6-core chips available.

Q3: the 4-core i5 does not support Hyper-threading. Does Resolve use Hyper-threading?

It depends if you are going to use the noise reduction feature of the Studio version (not free). It's really great quality noise reduction and you need a lot of GPU power to run it beyond the basic settings.

But regardless, I think you need to spend money on both GPU and CPU, it makes a big difference to have a powerful system, especially with 4K. The GPU needs to be latest generation because the performance is so crucial. But the CPU can be older. You may want to buy a used HP dual-Xeon workstation and put a new GPU in it.

If it was me I would buy at least 8-core (single or dual CPU, but make sure you have at least 8 cores or more total). And I would buy two Titan X or two 1080's. If you only buy one GPU then buy the Titan.

I have 12-core and they all work 100% when I'm exporting the final file, but that depends on the codec you use (ProRes and DNxHD definitely use all cores). And with a single Titan X I often run out of room for real-time playback of noise reduction. If I was to build a new system I would buy the 10-core 6950X CPU and two Titan X (new generation, Pascal). As for RAM, 32GB is more than fine, more will not really make a difference. So save some money there.

You don't specify which kind of file you're going to work with. Heavy decoding material (like GoPro/MP4/H264) require a robust CPU on top of a good GPU.

If you use uncompressed formats, you will need disk speed and disk space, don't discount that.

Which video card are you going to use? do you have enough Slots? enough PCI lanes? RAID cards?

...

You don't specify which kind of file you're going to work with. Heavy decoding material (like GoPro/MP4/H264) require a robust CPU on top of a good GPU.
...

I've yet to hear of a CPU combo that deals with h.264 well in Resolve. The Resolve decoder is simply not very efficient nor will it saturate the CPU's multi-threading capability. Over and over the answer seems to be to re-encode h.264 etc. to an intermediate format or suffer with a slow timeline for anything moderately demanding.

Thank you a lot

Based on what I've observed here, you want to focus on having not just enough GPU power, but also enough GPU RAM! 8GB is probably OK for 4K editing, but one user here seems to be starting to struggle with his 8GB card using all available VRAM with his 4K projects. So 12 GB might be better future proofing. If running two cards, it is best that they be matched in type and RAM capacity. Maybe a single 1080 GTX Ti with 12 GB is the way to go?

CPU seems to generally be less of an issue than GPU. CPU is used primarily for decoding and encoding footage. So if you do a lot of long projects that require a lot of encoding, then you might want to add power here. But for normal decoding of timeline footage, it seems like any reasonably powerful modern 6-10 core or better CPU will be adequate. My personal inclination would be to lean more toward higher clock speeds than extra cores. My thinking is that one of the toughest timeline decoding tasks is h.264 footage, and Resolve's decoding does not scale well with core count. It cannot come even close to saturating 12 Xeon cores. So it is probably better to have the fewer cores that do get spawned operating in the 4Ghz range rather than the 3Ghz range if you think you may want to use h.264 sources without intermediaries from time to time.

BTW, the many comments I've read here about possible Windows 7 inefficiencies while decoding h.264 prompted me to upgrade my home box to Win 10. My initial experience is that Resolve is marginally worse at decoding h.264 under Win 10 - not better.

h.264 editing will probably be problematic with Resolve for at least the near future. That means using a good intermediary or even more data dense format (raw) for footage that will more likely stress a drive than the CPU. So you probably want to make sure you have some really fast hard drives and plenty of space. I'm thinking SSD and perhaps SSD drives in RAID configurations.

Thank is the new nex generation annouced at CES CTX GPU the solution?
Which is the difference of one GPU vs two? Is it possible to add a third GPU devoted only to manage screens to have more power in the rendering final work? Consider that I'd like to work in 4K with graded footages on around 30 - 50 minutes of final work

It depends if you are going to use the noise reduction feature of the Studio version (not free). It's really great quality noise reduction and you need a lot of GPU power to run it beyond the basic settings.

But regardless, I think you need to spend money on both GPU and CPU, it makes a big difference to have a powerful system, especially with 4K. The GPU needs to be latest generation because the performance is so crucial. But the CPU can be older. You may want to buy a used HP dual-Xeon workstation and put a new GPU in it.

If it was me I would buy at least 8-core (single or dual CPU, but make sure you have at least 8 cores or more total). And I would buy two Titan X or two 1080's. If you only buy one GPU then buy the Titan.

I have 12-core and they all work 100% when I'm exporting the final file, but that depends on the codec you use (ProRes and DNxHD definitely use all cores). And with a single Titan X I often run out of room for real-time playback of noise reduction. If I was to build a new system I would buy the 10-core 6950X CPU and two Titan X (new generation, Pascal). As for RAM, 32GB is more than fine, more will not really make a difference. So save some money there.