The Seemingly Unnecessary Vram Increase Over Time

I brought up the issue of how much vram has increased over time at a different site (admittedly in an unrelated thread) and was not at all satisfied with the answer. I started the argument out by bashing Tweaktwown for posting Vram consumption and called it B.S. I now regret that since their data was very important.

So here is what I posted:

The article by tweaktown is sensationalism and rather irresponsible. By the end of it, they are basically having uninformed consumers run out and get GPUs with 12+ GB of VRAM "in order to play tomorrows games" since ME:SoM is shown to use 8.5 GB. This could have easily been validated by showing a large performance drop between the 6 GB 980ti and the 12 GB Titan or even between a 4 GB and 8 GB 390x. They also did not compare how different architectures and memory speed affected VRAM consumption which would be especially important with HBM since it is an entirely new beast.

Then I looked into it a little further. It would appear from their data that vram consumption didn't scale with resolution, but I in a way showed that it did:

I found it fascinating that 4k does not use 4 times as much memory as 1080p. Its like there is a
'y factor' where y is memory reserved despite resolution. Bare with me...

Take for example Tomb Raider which uses 1.5 GB ram at 1080p and 3.1 GB with 4k
Now use 2.077 (megapixels) for 1080p and 8.3 for 4k
Lets call 'x' the amount of vram needed / megapixel
and 'y' this vram overhead i mentioned earlier that is not affected by resolution.

Starting with 4k:
8.3x + y = 3.1 .... and now 1080p:
2.07x + y = 1.5 .... using subsitution,
8.3x + 1.5 - 2.07x = 3.1 ...reduce to x and
x=.253 or in other words .257 GB needed for each Megapixel
now we can solve for y:
2.07x + y = 1.5
y = 1.5 - 2.07x ....replace x with .257 and
y=.970

Now lets test with 1440p or 3.7 Megapixels which was said to use 1.94 GB

3.7x + y = 1.91 ---> pretty damn close!!




Just for fun, I tested again first using ME:SoM and i came up with
x = .1 GB and y = 4.56 where again x is GB/megapixel and y is the "game skeleton"
I tested on 1440 p and got 4.93 GB vs. 4.97 GB posted by tweaktown.

Then Metro Last light gave me:
x = .115 and y = 1.06
testing formula with 1440p gave me 1.49 GB vs. 1.46 GB that tweaktown recorded

ARE YOU FRICKIN KIDDING ME!!!

So if it wasn't for this mysterious 'y-factor' that has NO explanation,
we could play all these games with at 4k with 2 GB or below.

What was really fascinating is that the VRAM hog ME:SoM actually required LESS
VRAM/megapixel than Tomb Raider!!!

Last one I promise - Far Cry 4. This time i used 8.3 mp for 4k and 2.07 for 1080p (thanks rumartinez)
x gave me .43 GB/ megapixel (highest so far!) with "the skeleton" being 2.17 GB

Again testing on 1440p:
3.7x + 2.17 = 3.76 GB wait for it..... tweaktown reported 3.77 GB

The other forum members argued that things like AA and Z-buffering were the cause of this large 'y-factor' or as I like
to refer to it now as "skeletons"
So then what I did was used an older game that still used some of these modern day effects...


It took alot of digging but here is a link to vram usage in crysis 1:
http://hardforum.com/showthread.php?t=1456645

defaultluser reports .31 GB@ .48 MP, .36GB@ .79 MP .45GB@ 1.31 MP
and .575 GB at 1.9 megapixels

using 1.9x + y = .575 and .48x + y = .310
.....using substitution....

x = .187 Yep, thats right. Still the same GB/ megapixel as today
y = .22 GB much more reasonable. This was 4xAA btw.

Checking with .79 megapixels or 1024x768 .....

.79x + y = .368 compared to .36 GB that they recorded


So in review, all of these games had similar GB of memory used/ megapixel. What changed is how much this base skeleton increased.
Going from Crysis to ME:SoM has been a 20 times increase! The only good news out of this is that it will only take a couple of more
GB of VRAM to get to 8k in the future. Unfortunately, you will need 30 GB just to play at 1080p

As you noted, VRAM usage is less about the resolution of the game and more based on the individual game and their texture optimization (or lack thereof). Witcher3 is arguably one of the prettiest games available right now and even maxed out at 4k uses less than 2GB of VRAM. Compared to the poorly optimized Middle Earth: Shadows if Mordor and you see how they could say to basically use whatever is available (whether it is needed or not).

Nice work on doing the math there, adding things like higher AA and other graphical effects really brings up the VRAM usage in many titles. But I would argue that the higher the resolution the less AA is needed.

Thanks, I just thought it was amazing how much the game engines changed requirements for their skeleton. It makes sense that the
heavy duty FPS games like FC4 need more vram/MP as opposed to ME:SoM, but who knows if the base requirements for the game engine will
keep growing at this rate. If it keeps going this way, we will see something like 90 GB needed to play a game in 720p in 2021 (silver lining is that it will only require about 96 GB to play in 8k since the GB/MP hasn't moved much. Sometimes I think it is done on purpose so that a game will look more "elite" for needing these higher requirements. Compare this going from Windows 7 to Windows 10 where 8 GB of system ram is still plenty.Not exactly apples to apples but still rather interesting.

I would still imagine most games requiring significantly less vram than 8gb as most games are made for consoles and ported to pc. Both consoles have a grand total of 8gb of ram to dole out as necessary, not nearly enough to be holding onto 6gb worth of textures (or even 4gb).

For context, I believe this is the article he was referring to,
http://www.tweaktown.com/tweakipedia/90/much-vram-need-1080p-1440p-4k-aa-enabled/index.html

I actually liked the article, I thought that it showcased that you really did NOT need to go out and buy a high VRAM card to play the latest games at 1080 and 1440 which are the mainstream for gaming on.

Yep, that's the one. It's actually very informative. It mentions that above 4 gb is not need for 4k w/o AA for most games. With AA, we see some games needing more than 4GB, even at 1440p. I think it will be about 2 hardware generations before MAINSTREAM ($300) hardware can handle 4k any ways. At least for now, this all kind of works out to console's advantage (AMD) since there really is no 1440p in the living rooms. However, 4k televisions will be obtainable by the middle class starting this holiday season. Since we are still 4-5 years from XBOX 4 and PS5 (which hopefully would be 4k), PCs could finally make headway into the living room ... it will just have to be with a single $300 card that has 8+ gb vram and the power of SLI 970s.

I think I saw an article that suggested 4K resolutions on GTAV used more than 4 GiB of VRAM.

Ram usage is based on texture resolution as much as game resolution. You can fill the 6gb vram of a titan with modded skyrim. Even thought the entire base game could fit in the vram buffer of a titan once you start installing textures with 4/8/16 times the resolution that vram goes fast.

Then there is the balance between view distance and level of detail. If your world is being rendered 50 yards out at full detail it's going to take less resources than if it's rendered out 500 yards at full detail.

That's why vram usage has to be tested on a game by game basis and you can't just say 1080p needs this much and 1440p needs that much.

Edit:shoot I just saw that this is an older post with one new reply. Oops

Supertrucker said:

Ram usage is based on texture resolution as much as game resolution. You can fill the 6gb vram of a titan with modded skyrim. Even thought the entire base game could fit in the vram buffer of a titan once you start installing textures with 4/8/16 times the resolution that vram goes fast.

Then there is the balance between view distance and level of detail. If your world is being rendered 50 yards out at full detail it's going to take less resources than if it's rendered out 500 yards at full detail.

That's why vram usage has to be tested on a game by game basis and you can't just say 1080p needs this much and 1440p needs that much.

Edit:shoot I just saw that this is an older post with one new reply. Oops

Click to expand...

That makes sense. I'll bet NV's DSR increases VRAM requirements as well.

Skyrim w/a 6GiB VRAM memory load. That's amazing for a PS 2.0, DX9 game!