Unknown budget - vMix "Pro" production - PCIe Lanes connundrum (updated questions)

[Mikavelli]

Hi,

(sorry for lengthy post)

 

I have to prepare a build for in-house live video productions (that's why it's unknown, but still not "insane" budget; if Board member signs it - and he rather wants to start this project - we're golden)

So, here are the issues I have (aside from the fact that last time I really made PCs from hand-picked parts was in P4/Athlon times, later just quick component swaps at work and lots of theory):

 

So far we've worked with 4-8 FullHD sources via Blackmagic hardware switchers, but we'd like to dip our toes in multi-location sources (due to pandemic of course), and we'd want:

- vMix Call is main goal (up to 8 WebRTC sources),

- machine should be able to serve as replacement for FHD hardware solutions we use (so 4 inputs - with capability of up to 8 - and 2-4 streams+recording);

- 2-3 4K camera sources possible if someone will want 4K streaming (we'll go with hardware mixer sooner or later, no point in focusing on this too much);

- during longer breaks it'll serve as Adobe Suite workstation - we tend to keep 1-2 simultaneous renders while working on 3rd project, so I think this is what will also happen with this machine 

 

I've checked vMix (it's the only software aside from Livestream that can manage video calls properly) recommendations: https://www.vmix.com/products/vmix-reference-systems.aspx#obsidian

Hence my hope for succesful AMD build - it looks like I'm aiming at their top of the line specs anyway 

The goal is stability under long loads - so no overclocking here; RGB unfortunately will be turned off during this PC work hours

 

vMix did testing with Threadripper (PCIe4x64) - but even cheapest one is really more expensive than recommended i9 10th series.

On the other hand they hadn't tested i.e. 3950x (which is in my sights right now) due to "low PCIe lanes" compared to i9 10th.

 

UPDATE

I found the motherboard - Asus Pro WS X570-Ace - supports 8x8x8x setup via hijinks on the chipset - but based on bandwidth required by expansion cards and available on chipset-CPU route, it'll work (Blackmagic 8K Pro needs ~6GB/s, which leaves about 1.5-1.7GB/s left on PCIe4x4 chipset-CPU connection.

 

So, Now I'd like to focus on remaining questions - which RAM configuration is "optimal" for Ryzen 3950X, and are there "better" 2070/2070 Super/2080/similar models on the market I should focus on, or it's mostly "whatever you'll pick, it's fine"?

 

Bonus question (forgot about it in original post) - what kind of storage is recommended - I know (from LTT of course) that PCIe4 ones are not optimized yet, but is there basically Samsung EVO and that's it?

EDIT2 - and what cooler should I use for said Ryzen?

 

So here is my first question - since for GPU PCIe3x8 is oftenmost sufficient, Blackmagic capture cards require anywhere from PCIe2x8 to PCIe3x8, how will it work on PCIe4 config?

I plan on having:

- higher end 1xRTX (let's assume full PCIe3x16),

- 1xBlackmagic 8K Pro (PCIe3x8),

- 1x 4K Extreme 12G(PCIe2x8),

- maybe some throwaway card like audio or some not important connections we won't need in the next 2 years

effectively It'll "eat up" PCIe3x(8+4+?)+GPU -> up to 32 lanes in PCIe3.

 

I assume there should be no hickups, but still - Is it safe to say that PCIe4x16 is effectively PCIe3x32 dynamically (or manually) distributed as fit; or will it rather have a chance of failing spectacularly? I hope some of you actually ran few cards like blackmagic ones and could share your knowledge. Video ingest cards really require the bandwidth they claim they do - in "4th Intel era" I've used not supported motherboard - turns out the lanes were "fake" x4 in said mobo and only properly working was taken by GPU.

UPDATE ENDED

 

Then - dual channel vs quad memory - should I be concerned with it now, or is it rather a higher bar set by vMix to utilize 4K to it's limit? Any advice? What speeds should I run it at? 

 

GPU - I know that 2080Ti is higher bar set by vMix, so I'll choose something between RTX2070 Super and RTX2080, depending on resulting configuration (These GPUs are artificially limited to only 2 concurrent decode/encode streams anyway, but maybe I'll try unlocking this feature - Quadro RTX is prohibitively expensive)

 

Motherboard:

- As I've mentioned above, sooner than later we'll move to 10Gbps network for video editing - 2,5Gbps or 5Gbps should be more than enough for footage we record right now (BRAW 8:1), but still... )

Here are my picks (dual ethernet, one of those is either 5 or 10gbps; 3 full length PCIe +at least one x1)

ASRock X570 Creator

ASRock X570 Aqua

ASUS ROG X570 Crosshair VIII Formula

Is there something better/reliable about those picks, or is there a nicer alternative?

 

Is there some kind of PC case (so normal-ish tower) that would be "rack moddable" - as in by attaching made by manufacturer rails/brackets to let it sit safely on the bottom when we'll start using it as mobile broadcast/switching table? Or I'm just looking for something that does not exist?

[SpaceGhostC2C]

16 minutes ago, Mikavelli said:

 

I assume there should be no hickups, but still - Is it safe to say that PCIe4x16 is effectively PCIe3x32 dynamically (or manually) distributed as fit; or will it rather have a chance of failing spectacularly?

No. PCIe4x16 i equivalent to PCIe3x32 in terms of bandwidth, but any "split" of bandwidth across physical slots and bandwidth share must be bulti-in the motherboard with some sort of switch over the PCB traces. Therefore, you'll need to check the manual of the motherboard you are considering for the different supported layouts.

For example, I have a first-gen TR board with 4 physically x16  PCIe3 slots and an x1 PCIe2 slot. The big slots have 48 lanes total, but I can choose which to run at x16, x8, or even x4, with some restrictions (the first one is always x16, the others admit some variation).

I think the best you can do is to check the motherboard's spec page or the manual (they are all available at the manufacturer's website) and allocate devices to the physical slots, taking into account which layouts would be available to you.

 

Can't say much about the rest, I'm afraid I'm not familiar with your use case.

[igormp]

4 hours ago, Mikavelli said:

GPU - I know that 2080Ti is higher bar set by vMix, so I'll choose something between RTX2070 Super and RTX2080, depending on resulting configuration (These GPUs are artificially limited to only 2 concurrent decode/encode streams anyway, but maybe I'll try unlocking this feature - Quadro RTX is prohibitively expensive)

Just throwing this in for you.

[Mikavelli]

6 hours ago, SpaceGhostC2C said:

No. PCIe4x16 i equivalent to PCIe3x32 in terms of bandwidth, but any "split" of bandwidth across physical slots and bandwidth share must be bulti-in the motherboard with some sort of switch over the PCB traces. Therefore, you'll need to check the manual of the motherboard you are considering for the different supported layouts.

For example, I have a first-gen TR board with 4 physically x16  PCIe3 slots and an x1 PCIe2 slot. The big slots have 48 lanes total, but I can choose which to run at x16, x8, or even x4, with some restrictions (the first one is always x16, the others admit some variation).

I think the best you can do is to check the motherboard's spec page or the manual (they are all available at the manufacturer's website) and allocate devices to the physical slots, taking into account which layouts would be available to you.

 

Can't say much about the rest, I'm afraid I'm not familiar with your use case.

If I'll check slots in x8, x8, x4 pcie4 (as 3 candidates seem to support) will it mean x16 x16, x8 pcie3 bandwidth for connected components (especially GPU and 3rd add-in which requires "pcie2x8") or is there some caveat I missed? I hope in such scenarios full slot is still "wired" to cards properly despite lowered "X" values.

[SpaceGhostC2C]

1 minute ago, Mikavelli said:

If I'll check slots in x8, x8, x4 pcie4 (as 3 candidates seem to support) will it mean x16 x16, x8 pcie3 bandwidth for connected components (especially GPU and 3rd add-in which requires "pcie2x8") or is there some caveat I missed? I hope in such scenarios full slot is still "wired" to cards properly despite lowered "X" values.

Good question. I don't know if a device that is built for PCIe3  x16 will use the full bandwidth of PCIe4 x8. PCIe is backward compatible, so it will work, but I do not know if the PCIe swtich disables physical connections so the device is left with fewer functional pins. It could happen in that case that a PCIe3 device can0t use the remaining pins to work at x16 speeds, even if the motherboard supports additional traffic through those pins...

I'm sorry I can't be more helpful, you need someone with better knowledge  

[igormp]

11 hours ago, Mikavelli said:

If I'll check slots in x8, x8, x4 pcie4 (as 3 candidates seem to support) will it mean x16 x16, x8 pcie3 bandwidth for connected components (especially GPU and 3rd add-in which requires "pcie2x8") or is there some caveat I missed? I hope in such scenarios full slot is still "wired" to cards properly despite lowered "X" values.

No. The moment you plug a PCIe 3.0 card in a 4.0 slot, the slot is going to fall back to 3.0 and you're going to lose half of the bandwidth the slot could offer. It will still eat up from your total of lanes (i.e.: 48 4.0 lanes in total, you plug a 3.0 x16 card, you're left with 32 4.0 lanes).