Upgrading my system: when is an 8GB GPU REALLY not enough?

OK, so before I finally make up my mind whether or not to step up for 12GB Titan X or stay with another GTX 1080 with 8GB - please give me an example scenario of 8GB definitely being not enough for 4K editing/grading.

Like would it be TNR with say 5 frames? Or Multi-camera timeline? Or some specific OFX? TIA

Piotr

Hi Piotr,

How does it perform already with a 1080 / 8Gb for noise reduction for example ? And with what kind of footage (prores/uncompressed)?

You said for "editing" in 4K, but I guess you mean for color-grading in 4K right ?
Cause I don't see any interest in editing in 4K (optimized media in 1080p would probably be enough).

I also heard already that if you want to make a dual GPU system, it is better to use the same graphic cards, cause in case of two different GPUs, the best one will be limited to the lower one's performance. I'll be happy to have another opinion on that because I never double checked this. But it would mean that if you add a Titan to an existing 1080, the number of cuda cores actually used by resolve would be limited to the 1080. From what I heard, it is because of the Nvidia drivers. Once again, I'll be glad to heard another voice about it and I don't know if it is also the case for GPU memory (I heard it only about the number of process stream used by the soft on the GPU).

easy enough to test the limits of the 8g card you have now
- install a GPU monitoring software, open it on top
- select an ACES project
- select 4K + footage
- debyaer & cache to DNxHD444_HR
- playbck
- watch the GPU monitor
does it play back with reasonable overhead on your current single 8g card? (i would expect so, if not search out the bottleneck, maybe disks or CPU)

- add Resolve native NR/ temporal 5
- add a temporal OFX like BCC's flicker fixer, set that to temporal/5
- playbck
- watch the GPU monitor

does it still play back with reasonable overhead on your current single 8g card? if a bottleneck is reveled, what is it? GPU cores? (add another 8 gig card, or start cacheing) GPU memory? (reason to get a 12g card)

Hi Piotr,

How does it perform already with a 1080 / 8Gb for noise reduction for example ? And with what kind of footage (prores/uncompressed)?

You said for "editing" in 4K, but I guess you mean for color-grading in 4K right ?
Cause I don't see any interest in editing in 4K (optimized media in 1080p would probably be enough).

Hi Alex!

Well - it actually performs quite good, and even though I don't use a separate GPU for UI I'm usually using no more than 7GB out of the 1080's 8GB. I amost exclusively do Sony Slog UHD or DCI 4K footage. And yes - I said "editing" in the general meaning of the verb; of course I do mean "grading" as well (perhaps first of all).

I also heard already that if you want to make a dual GPU system, it is better to use the same graphic cards, cause in case of two different GPUs, the best one will be limited to the lower one's performance. I'll be happy to have another opinion on that because I never double checked this. But it would mean that if you add a Titan to an existing 1080, the number of cuda cores actually used by resolve would be limited to the 1080. From what I heard, it is because of the Nvidia drivers. Once again, I'll be glad to heard another voice about it and I don't know if it is also the case for GPU memory (I heard it only about the number of process stream used by the soft on the GPU).

I realize that; adding a 12GB Titan X to my current GTX 1080 will not increase the VRAM amount available to Resolve. But when I'm ready to upgrade again some time down the road, it'll be easier on my pocket to replace the single 1080 with another Titan, than it would be to replace 2 cards at the same time. So I'm considering adding Titan as an interim solution

Piotr

easy enough to test the limits of the 8g card you have now
- install a GPU monitoring software, open it on top
- select an ACES project
- select 4K + footage
- debyaer & cache to DNxHD444_HR
- playbck
- watch the GPU monitor
does it play back with reasonable overhead on your current single 8g card? (i would expect so, if not search out the bottleneck, maybe disks or CPU)

- add Resolve native NR/ temporal 5
- add a temporal OFX like BCC's flicker fixer, set that to temporal/5
- playbck
- watch the GPU monitor

does it still play back with reasonable overhead on your current single 8g card? if a bottleneck is reveled, what is it? GPU cores? (add another 8 gig card, or start cacheing) GPU memory? (reason to get a 12g card)

Dermot,

believe me that before even posting this question, I tried as heavy stuff on the Color page as I possibly could, including 5 frames TNR. I don't have access to any OFxes (apart from Resolve's own), so I tried with adding film grain, various blur options, lens flare etc - and apart from working harder while caching, my GTX 1080 never complained about its VRAM being overfilled (as I said above, even for DCI 4K footage it maxes at some 7 GB of usage). Having said that, I realize than I'm only barely scratching Resolve capabilities, and it's certainly possible to thow even more heavy and memory-hungry stuff on my clips... Hence this post. Thanks,

Piotr

Hi Piotr

Good to hear that it is performing good on your gtx1080.
I would personally go for another gtx 1080 more than buying a Titan which costs two gtx 1080 now...
I think adding a Titan to your existing gtx 1080 will increase the Vram available and the number of cuda cores used by resolve. But what I meant was (from what I heard) that it would not increase it by 12go and around 2500cuda cores (not sure of the exact number) but by 8go and around 2000cuda cores...so the Titan would perform pretty much like another gtx 1080 (regardless of other factors...) Again I'll be happy to have confirmation of that behavior by anyone.

... it would [...] increase it 8GB and around 2000cuda cores...so the Titan would perform pretty much like another gtx 1080 (regardless of other factors...)

You're right, Alex - I realize that a Titan X + GTX 1080 combo would compute only as fast, and have access to only as much VRAM, as 2x GTX 1080. This is why I stated i only consider buying the Titan instead of another 1080 as an interim solution, in order to spread my costs over a longer period of time.

Also, I'd hope that while my GTX 1080's 8GB VRAM is partially consumed by Resolve UI (on my current Asus motherboard there is no room for 3 GPU cards, with Decklink 12G taking up 2-slot space) - with Titan X added to GTX 1080, I'd have entire 8GB of VRAM for computing if I hooked up my monitor(s) to the Titan, as the UI would have the difference (12-8=4GB) for itself. But this is just speculating on my side, and I'd love somebody from BMD support to chime in and authoritatively confirm or deny...

Piotr

I realize that; adding a 12GB Titan X to my current GTX 1080 will not increase the VRAM amount available to Resolve. But when I'm ready to upgrade again some time down the road, it'll be easier on my pocket to replace the single 1080 with another Titan, than it would be to replace 2 cards at the same time. So I'm considering adding Titan as an interim solution

Piotr

I came to these general guidelines for purchasing workstations and similar electronic/digital technology fairly early.

1) Try to stay off of the bleeding edge of tech unless you have a real and current need (as opposed to desire/want). The bleeding edge is expensive. One or two steps back from the edge will typically give you a lot more performance for your dollar.

2) Try to avoid upgrading until you can double the capicity or performance of whatever it is you want to upgrade. At a minimum you want an increase of at least 50%. Doubling is preferred. See point 1 to determine if you even should be upgrading.

3) Generally avoid purchases "for the future." Things will almost always be cheaper if you upgrade/purchase when you really need it and often they will be cheaper and better. Money not spent today will buy more tomorrow ... when you actually need it.

If I were you, I'd probably install a second 1080 8GB card since you haven't defined a real need. I'd put the other money aside for a possible 16GB card down the road.

Of course, if you just enjoy having the tech you should ignore my guidelines entirely.

+1 jay's observations.

the problem with being on the cutting edge is you bleed to death very quickly ;-(

Jay - all perfectly valid points!

I must admit i do have this tendency of "buying for the future", but that's because of my age (62) and poor health (serious condition after 2 unsuccessful neck spine surgeries). So I'm still unsure whether I'll ever be able to buy high-end technology in the future, if I don't buy it now

I guess I will try to be more optimistic, and follow your advise though Thanks!

Piotr

I must admit i do have this tendency of "buying for the future", but that's because of my age (62) and poor health (serious condition after 2 unsuccessful neck spine surgeries).

There are always other things to consider. That is why I emphasized "general guidelines." It's just food for thought. If we could really decide these things with simple formulas it would take a bit of the fun out of it. :^)