Blackmagic Forum

Hi everyone,

first of all a brief overview on my current situation. I just upgraded from an old Intensity Pro card to the newer 4K version. Using 2 GUI-Monitors (WQHD) and one preview-Monitor connected to the intensity pro I just figured out that my GTX 1080's 8GB of VRAM are apparently bottle-necking me atm.

Just as a remark the other specs of my system:

CPU: i7-6900K running @3.9GHz
RAM: 64GB DDR4
Drives: 512GB SSD, 4-bay RAID 0 providing around 550MB/s, 2-bay RAID 0 providing around 250 MB/s.

So apart from fighting to get smooth 25 fps playback on uncorrected footage, I occasionally get a report that the GPUs VRAM ran full.

Now my questions:

1. Would you expect a major benefit from getting another GTX 1080 (i.e. perfomance increase of 35% or more) or would i probably just run into VRAM limitation of 8GB once more?

2. Would an upgrade to a single 1080TI or to a 1080 and a 1080TI give a significant boost over the double 1080-configuartion?

3. Speaking of adding more GPUs: I got another Lan Card (for my CC-Interface), a Intensity Pro and a Raid controller connected to my mainboard. That gives me 5/6 PCIe-Lanes occupied atm. Means i probably will have to use some sort of PCIe splitter/riser. Do any of you guys have had positive experiences using one of those for adding in another GPU or combining other devices such as LAN-card and Intensity Pro?

I would really appreciate if you could comment on any of those issues. I tried to use the forum search, but couldn't really find a satisfying answer to it. If there is one already, please feel free to dip me into it

Thanks in advance!

Wolfgang

What kind of footage?

Are you using Resolve Studio?

What timeline resolution and what are you doing when you get the GPU VRAM message?

8G of VRAM should be adequate for most things.

Adding a second card will not give you more VRAM. VRAM across cards is not additive. If you have 4 1080 cards, you still have 8GB of VRAM.

Hi Dwaine,

Primarily 4.6k UMP 4:1 or 3:1 RAW Fototage, graded in a 4k Timeline in Resolve Studio.

Reducing Number of Nodes or changing timelime Resolution. Both works.

So I guess only changing the Card will do the Trick. So arm there seem to be 4 reasonable cards to me:

GTX 1080ti (11GB Vram)
AMD Vega 64 8+Hbcc it Resolve can use that
AMD Vega 64 FE 16+HBCC
AMD Pro Duo

Any recommendations on one of those?
Thank you!

That footage type has GPU accelerated decoding. So more GPU's would help that scenario.

4K footage on a 4K timeline is probably a bit much for a single GPU.

I haven't tested any of the Vega GPU's, so I would probably default to the 1080Ti.

If you wanted to add more GPU's, you'd need a PCIe expansion chassis. We list some Cubix and Cyclone options in the Resolve Config guide.

Dwaine Maggart wrote:I haven't tested any of the Vega GPU's, so I would probably default to the 1080Ti.

I don't think I've ever seen the Vega beat the 1080Ti in a post-production benchmark.