VRAM for BF4 for Surround

[UaVaj]

currently running i7-3770k (4.7GHz oc) w/ 680 4GB trisli (stock).
BF4 at 6000x1080 resolution with everything maxed out. OGSSAA at 100% (OFF).

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VRAM is hovering at 3.3GB on any given map at any given time.

is this allocated VRAM or is this actual usage VRAM. who knows how to test for?

looking to upgrade to 780ti trisli. wondering if 3GB VRAM is enough to run bf4 maxed out in surround resolution?

also looking to upgrade to 4930k too.


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update.

per BrightCandle's methodology
2.3GB to 2.4GB at the beginning of the game depending on the map.
then it eventually climb to 3.3GB to 3.4GB and stays there though out the game.
vram usage recycles for the next round/map

a comparison: 1920x1080 w/ same settings.
1.2GB to 1.4GB at the beginning of the game depending on the map.
then it eventually climb to 2.2GB to 2.3GB and stays there though out the game.
vram usage recycles for the next round/map

if anyone knows a better method to test for "actual" vram usage. all ears.
otherwise will live with bright candle's method.

next question. anyone knows how much "cache" vram above actual vram one should have for a good buffer?

 

[OCGuy]

Any reason you leave your cards stock?

 

[UaVaj]

currently cpu bottle neck. oc-ing the 680 (1202 core / 1800 memory) yields no fps gain.

since upgrading cpu to 4930k. might as well upgrade gpu too.

need to verify if 3gb is enough for BF4 everything maxed. otherwise will have to wait for maxwell (gtx 880).

 

[OCGuy]

I certainly wouldnt spend money upgrading that system to more 28nm tech.

 

[Majcric]

I think 3gb Vram will be enough for BF4, but do you really want to waste that much money on 3gb Vram. Nvidia should have never released the 780/ti with only 3gb vram. This has left Sli users out in the cold. I would personally would wait for 6gb 780/ti cards or Maxwell. I'm waiting for Maxwell.

 

[Carfax83]

I'd worry less about VRAM, and more about bandwidth. You're going to run into bandwidth limitations long before you hit a VRAM wall..

The GTX 680 has a 256 bit bus, which doesn't provide enough bandwidth for that resolution for smooth gameplay. A 384 or 512 bit bus would be much better..

 

[BrightCandle]

About the only real way to test BF4 likely VRAM usage is to take it right at the beginning, the moment you first spawn into the game and can see. After that point any amount of VRAM usage is based on a cache result and isn't representative of what the game appears to need, but rather what it can use. Its as close as we can get currently to knowing how much VRAM it actually needs without having a similar class of hardware with less VRAM.

 

[UaVaj]

Majcric
not a believer of future proofing. that is a fallacy many fall into.
simply buying what is necessary to get the job done today.
will upgrade again (as many times as necessary) should the job change and demand change.


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Carfax83
high resolution does need more memory bandwidth.
however 256bit < 384bit < 512bit memory interface. that is a myth.
gtx 580 w/ 384bit interface n 1000 memory = 192GB/s
gtx 680 w/ 256bit interface n 1500 memory = 192GB/s
290x w/ 512bit interface n 1250 memory = 320GB/s
780ti w/ 384bit interface n 1500 memory = 336GB/s
there more to it than "just" 256bit vs 384bit vs 512bit.
imho - with 3 GK104 pushing. 192GB/s is not even saturated yet.


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BrightCandle.
that measurement would be 2.3GB to 2.4GB depending on the map. then it eventually climb to 3.3GB to 3.4GB.

is this suggesting minimum VRAM needed is 2.4GB?

 

[guskline]

UaVaj: Did you upgrade the system to a 4930k yet?

 

[UaVaj]

UaVaj: Did you upgrade the system to a 4930k yet?

still motherboard shopping. looking for a pcie 1/4/7 so there is 1 slot between each gpu for better cooling.

 

[Hdgamer]

If you look around on the web you can find reviews of 290X vs 780ti tested at 4k resolution. You will find the 780ti wins in almost all games, regardless of it having less vram at that resolution and 4xmsaa. The 780ti has a superior architecture and is overall a bit faster. A faster card wins hands down over having more resources available. If you had a [dumpy] cpu and tons of ram in your system, your system would still be slow.

Now if you're dead set on "futureproofing..." LOL... The Titan Black is coming out. It's basically a 780ti with 6 gigs of vram and double precision. Of course you're going to be paying a premium for that too.

Profanity isn't allowed in VC&G
-Elfear

 

[Carfax83]

Carfax83
high resolution does need more memory bandwidth.
however 256bit < 384bit < 512bit memory interface. that is a myth.
gtx 580 w/ 384bit interface n 1000 memory = 192GB/s
gtx 680 w/ 256bit interface n 1500 memory = 192GB/s
290x w/ 512bit interface n 1250 memory = 320GB/s
780ti w/ 384bit interface n 1500 memory = 336GB/s
there more to it than "just" 256bit vs 384bit vs 512bit.
imho - with 3 GK104 pushing. 192GB/s is not even saturated yet.

I should have expounded a bit more. What I should have said is that the GTX 680 in particular doesn't have the bandwidth and ROP count for smooth gameplay at such high resolutions..

I bet that if you overclock the memory, you will notice a significant performance increase. The GTX 680, and to a lesser extent the GTX 770 are somewhat bandwidth limited as both tend to gain more performance from memory overclocking than from core overclocking; at least in my experience..

When I overclock the memory on my GTX 770s, I notice much smoother frame rates in certain demanding games, like Crysis 3.. And in BF4, when large destruction events occur like the skyscraper falling (with all of the dust and particles) overclocking the memory outright removes the accompanying frame rate hit.

 

[Unoid]

Thge [h] review of 290x xfire vs 780ti sli shows the radeons owning at eyefinity/4k res.

You may want to consider 2-3 290x's

 

[UaVaj]

CarFax83
as for improving performance by overclocking the memory to increase the memory bandwidth.
with the i7-3770k. this is moot. (see post #3).
BF4 Multi Player is very CPU intensive.


Unoid
thanks for the suggestion. was only a matter of time before 290x is mentioned.
as nice as three 290x is. will not tolerate "still" cross broke (can only imagine KaRLiToS's headache). also not interested in going underwater.
clealy need an "out of the box" experience. that = nvidia.
SLI is still smoother. nvidia driver are still better. less heat and less noise with blower cooling for sandwich gpu. amd is a tough sell right now.

 

[OCGuy]

If you believe you are CPU limited, shouldnt you confirm that isnt the case with a new chip? Any CPU gains from that upgrade could be matched by ocing the cards. That should hold you until 20nm.

 

[UaVaj]

this is the planning stage.

cpu is definitely on the order. need more IPC (since BF4 only uses 4 core). so need 6 core (4 core dedicated to BF4 and 2 core for other programs in the background).

then will oc the 680 trisli. hopefully this bring performance where it needs to be.

upgrading is obviously contagious. so, if there is IPC left on the cpu. then will consider upgrading gpu to match. thinking 780ti sli might be the sweet spot. 780ti trisli may cause a cpu bottleneck again.


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BF4 is the true benchmark when it comes to taxing both cpu n gpu. simply too bad dice does not have a 64 player simulated in-game benchmark. that would take out a lot of the guess work.

 

[blackened23]

Out of curiosity, what type of AA and resolution scaling are you using in game? I think 3GB will be fine, but I don't know if you mentioned anything about BF4's resolution scale. Resolution scale is OGSSAA which tends to severely skew VRAM usage at any resolution, so i'm not sure if that's the reason for the 3.3GB that you have in use. For instance, even at 1080p you can go way way past "typical" VRAM requirements by using OGSSAA / resolution scaling. Like, normal use at 1080p would be around 1300-1500MB, but if you use OGSSAA it can go up way past that since OGSSAA upscales all rendered images to a higher resolution. And performance will drop tremendously, as well, but with tri-sli not so much.

MSAA also contributes heavily to VRAM use, but not nearly as much as OGSSAA.

It could be VRAM caching as well.

 

[blackened23]

Pretty sure UA has extensive experience with "cross broke" surround as I have, so probably not a consideration, but I don't know if he had a change of heart. Highly doubt it. Plus with triple mGPU you need reference cards for "sandwiching", and we all know what the deal with 290 reference cards is. Hot, loud, requires ridiculously high manual fan speeds to prevent throttling while using tri crossfire. That doesn't sound too tantalizing to me personally...

 

[TheSlamma]

this is the planning stage.

cpu is definitely on the order. need more IPC (since BF4 only uses 4 core). so need 6 core (4 core dedicated to BF4 and 2 core for other programs in the background).

If only these OS's and applications were that smart.

 

[lehtv]

If only these OS's and applications were that smart.

thread affinity

 

[UaVaj]

blackened23
OGSSAA is 100% (OFF). so it is rendering at 6000x1080. as for everything else. it is set to "ultra" aka maxed. based on bright candle's methodology. 2.4gb of actual vram minimum. see post #7 n #8.



TheSlamma n lehtv
obviously the OS is not smart enough to allocate workload to the desire core without the use of thread affinity. however with 6 core available. the workload will be better spread out. all it take is one core to be maxed out to cause a bottleneck.

 

[Deders]

I believe that it is very difficult to get an exact measurement of the actual video ram in use, so it may appear to be more than it is.

Maybe this is to do with caching, not removing what is unneeded in case it is needed again, saving the data from being passed over the PCIe bus again.

 

[Carfax83]

CarFax83
as for improving performance by overclocking the memory to increase the memory bandwidth.
with the i7-3770k. this is moot. (see post #3).
BF4 Multi Player is very CPU intensive.

It's GPU intensive in certain areas though, and the resolution you're playing at is automatically GPU limited.

For example, you said that the frame rate dips into the 30s during the Skyscraper destruction. Thats a scripted destruction event that is very GPU intensive due to the all the particles and debris that are on screen.

I've noticed similar frame rate dips myself during those scripted destruction events, and overclocking the memory always mitigated it..

 

[Deders]

6GHz 265 bit memory actually limits Kepler hardware quite a bit, I get a huge improvement across the board just by overclocking close to 7GHz.

 

[UaVaj]

CarFax83
with a 3930k w/ 770sli. plenty of IPC left to push. overclocking 770s yields more fps.
with a 3770k w/ 680trisli. out of IPC. overclocking 680s yield near zero fps.
with a 4930k w/ 680trisli. overclocking 680s should yield more fps as you predicted.

nenforcer
Titan Black (aka 780ti 6GB) sounds promising.

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if anyone knows a better method to test for "actual" vram usage. all ears.
otherwise will live with bright candle's method.

next question. anyone know how much of "cache" vram is a good buffer?