Vram min 4k

[rotan1999]

hi. i want to play DCS FC3 at 4K. how much Vram is ok?

some nvidia cards i am looking at have between 12gb and 16gb

how much Vram should i have?

[kksnowbear]

Without going into a ton of detail:

Bottom line is 'the more the better' and that's just the way it is.

That being said, anything over ~11G (as with 1080Ti, 2080Ti...) is *adequate* in terms of VRAM.

However, it depends.  The settings you use will have an impact on VRAM used, and on performance as well.  The question is not strictly "How much VRAM do I need at 4k"

As a comparative example: A 3090 is *far* better than a 2080Ti in terms of performance.  The 2080Ti has 11G VRAM and will run 4k - but we must ask "At what frame rate, and with what settings?"  I think it should be obvious the 3090 will run 4k at far higher frame rates and higher settings.

So, while it is definitely a good idea to consider minimum VRAM, you should also seriously consider what kind of performance you're expecting/will get.

Following are some estimates:

There is a 4060Ti 16G model, but I believe it's performance at 4k would be fairly poor (<20FPS??)

A 4070 has 12G, and better performance than the 4060Ti 12G - but still, frame rates at 4k won't be too impressive (~25 FPS??)

(The reason I have ??s after the estimated FPS above is because - again - it depends on settings, the map, MP or SP, etc etc etc....please keep in mind these are broad estimates.  Also, read below about DLSS.)

Realistically, to even approach 60FPS at 4k, you're looking at cards that inherently have more than 12G:
3090 (24G)
3090Ti (24G)
4080 (16G)
4090 (24G)

...and *maybe* a 4070Ti at 12G (though the frame rate would probably be ~30)

(There is also a 12G 3080Ti, though it's 4k frame rate is likely to be in the 20's.)

Kindly note the estimates above are for higher settings.  If you are OK with lower settings, you could probably improve on these estimates a bit.

Something else important to consider: If you intend to use an Nvidia card, then I believe it is accurate to say that any Nvidia card with 12G VRAM or more will also support DLSS.  Wihtout going into a ton of detail here, a forthcoming DCS patch is supposed to add DLSS support.  So, *if* you can live with the trade-offs in terms of quality, DLSS can increase frame rates substantially.  It depends, of course, on how well it's implemented, as well as a lot of other factors...but it is remarkable technology that can improve frame rates quite a lot (at the expense of some quality).

The potential downside is that you might not care for the 'quality cost' of how DLSS performs in DCS, and that's a factor that, unfortunately, cannot be predicted.

But it is something to be aware of, and it's significant.

I believe people start off thinking they're going to game at 4k, up until they realize what kind of hardware is needed to deliver *decent* performance (and the cost thereof).  In fact, this is the second thread I recall with this very subject, fairly recently.

Nothing wrong with it, mind you, just I think people truly don't realize why 4k gaming is still really *very* ambitious (and very expensive).

Edited October 17, 2023 by kksnowbear

[SharpeXB]

I was running DCS in 4K with a 2080Ti at maximum settings and it was totally fine, giving up to 60 FPS no problem. My CPU was the limiting factor. That was in version 2.8 as well. A 4090 will run 120 FPS in 4K unless there is a CPU limiting situation. 

[kksnowbear]

Below is a video showing 3840x1600 at High settings (not 'max') and he gets 50's-70 with a 2080Ti.  There are times it is down below 50, depending on the map and down around the deck (which is typical).

3840x1600 is only about 75% the pixel count of 4k, so... seems fairly likely you'd get less performance with a resolution that's 35% higher...

As I said it depends on a lot of things.  I didn't specifically mention altitude, but that's a big factor as well.  Frame rate can drop 30% just by going down at 'tree top' especially when the area is populated with lots of buildings.

Another/different example: I have a friend, we both got 3090s at about the same time (I since went to a 4090).  He has run DCS tests at very high settings at 1440p and frame rate dropping to ~70 at times on both Normandy and Syria maps.

Not 4k obviously, but if his settings drop FPS to 70 at only 1440p with a 3090, it seems really unlikely he'd get even 60FPS at 4k.  Somehow I doubt a 2080Ti is going to do better than a 3090.

 

Edited October 17, 2023 by kksnowbear

[LucShep]

For DCS at 4K resolution, it really depends on the map and aircraft module...

If you're solely using FC3 aircraft modules on Caucasus map only (the lightest content available, least demanding on resources), then an RTX4070 12GB or RTX3080 10/12 GB will manage 4K quite well, at high settings with DCS 2.8. No problem there, all good, even VR is doable.

But then if you're using the much higher detail modules (F-14A/B, AH-64D, etc) with any of newer maps (Sinai, Syria, S.A., etc), then the problems can and will start, being far more demanding on resources. Here, at 4K, you'll certainly exhaust the VRAM of those mentioned GPUs (VRAM load/consumption can surpass 14GB quite often), and the performance hit will also require some (re)adjusted settings.

DCS is a friggin monster, with many optimization issues (textures are notoriously overkill, well known and documented), and don't even think for a second that the upcoming DLSS (for Nvidia RTX GPUs) and the presumed FSR to be implemented later (for actually all GPUs) will aliviate the VRAM load/consumption issues (it won't), as that is a totally different subject - upscaling atempts to improve performance (framerate, gpu usage, etc) - DCS really requires direct intervention on the textures (size, formats, count, etc). 

So, as of today, it pays up, in the imediate and longer term as well, to get a stronger GPU than those two mentioned, with 16GB (or better). It's not funny to spend $600+ on a GPU only to find a VRAM hard limit on it (hello st-t-t-tuttering!). Another example, an RTX4070Ti has great performance, but then has "only" 12GB of VRAM... 

Edited October 18, 2023 by LucShep
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