Investigating The Frostbite Mantle Implementation

Apache14 · 1 Jul 2014 at 10:51

Reading this thread I don't instantly jump to the conclusion that BF4 / Frostbite is broken in regards with mantle, here is my reasoning.

Other mantle games increase in memory usage when comparing DX to Mantle
Normally memory management relates issues at this level would result in an ever expanding use of memory (memory leak). This is not what we are seeing

I think that the mantle API is probably slightly more VRAM hungry than DX11, and depending on the implementation of this API in different engines some will be see a greater jump in VRAM when compared to DX (in this case frostbite could just be very unlucky and need very VRAM hungry operations when comparing to DX)

Also depending on how "back to the metal" mantle is and how much control it gives over the VRAM memory management small differences in the game engines implementation if the mantle API could see major inconsistencies between the DX to Mantel VRAM usage differences per game.

Im going to put it down to the following :-

Mantle is still in closed beta so we wont know if the cause is within mantle itself, and if it is ..... its in beta so expect some bugs
Frostbite (BF4) was the very first game to implement mantle, its implementation could well be "rough" in comparison to others

Ill just go play some BF4 with the fps boost of mantle

ubersonic · 1 Jul 2014 at 11:02

Sin_Chase said:
Just because a behaviour occurs in 1 game engine and not another does not mean the game engine is at fault. It could be a Mantle bug with a particular process in Engine X that Engine Y does not even use. Is this the fault of the engine? Could be, but not necessarily.

Good point, but Johan's tweets to LtMatt would seem to admit fault.

mmj_uk · 1 Jul 2014 at 11:23

In the other thread people are reporting that Thief has similar issues at 4k resolution, it could be a number of things...

1> Mantle simply requires excessive amounts of memory (compared to DX).
2> Mantle is not yet optimised to minimise memory usage.
3> Developers being lazy with memory management (LtMatt's claim).
4> Mantle has memory management issues (it's still in BETA afterall).

LtMatt seems more interested in absolving AMD of any blame and deflecting it onto developers though (surprise surprise).

LtMatt said:
It's not Mantles fault and It's not AMD's fault.

LtMatt said:
This is not a Mantle problem, this does not occur on Thief or Starswarm. This is an application issue and the responsibility to fix it lies solely at the feet of Johan Andersson/Dice/EA.

LtMatt said:
It's also a bit unfair to see AMD labelled with the blame when there is nothing they can do to improve vram usage under the frostbite engine when using Mantle. It is an application issue!

Mantle is still in BETA but it's perfect right? LtMatt knows for certain that AMD aren't to blame and you should all believe him because he's not massively biased towards AMD at all.

ubersonic · 1 Jul 2014 at 11:36

mmj_uk said:
LtMatt seems more interested in absolving AMD of any blame and deflecting it onto developers though (surprise surprise).

Hey that is a big surprise, after he was so quick to blame Nvidia for Ubisoft's failings I thought he would be sticking the dagger straight into AMD.

LtMatt · 1 Jul 2014 at 12:01

ubersonic said:
Good point, but Johan's tweets to LtMatt would seem to admit fault.

Indeed, it is the case. They've already admitted fault. Mantle puts full control into the hands of the developer, that includes things like memory management.

~Mike~ · 1 Jul 2014 at 12:20

Dice are just useless.

Ian Evey · 1 Jul 2014 at 12:33

It makes me wonder if they had not implemented mantle into bf4 if they would have more time to actually fix the game.

I have not played it for 3 months, and i wont be buying bf5 or harline or anything related to battlefield untill i see its worth it.

70 pounds for premium was a total waste of money for me.

PhysicsMan94 · 1 Jul 2014 at 13:02

Whatever the case, this quote from a different thread is very apt:

MjFrosty said:
Mantle does seen to devour VRAM, it's left down to the developers to keep tabs on it and they're obviously a bit new to it as it's always been controlled by Direct3D till now.

Microsoft maybe need a bit more credit than they get currently

After the release of Mantle I saw lots of pro-AMD guys on this forum suddenly talking crap about Microsoft and saying how bad DirectX is (even though that's the API which has been driving PC gaming for the past goodness knows how long). With the issue highlighted in this thread it is becoming clear that Microsoft do actually know what they are doing and their huge amount of experience with API development and memory management means that they create software based products which are very efficient regarding hardware resources.

AMD have a long way to go with Mantle...

ubersonic · 1 Jul 2014 at 13:03

So basically they implemented DX11, badly. Then added Mantle, badly. Maybe just focus on one API next time DICE lol, or spend more time/money so at least one works properly

humbug · 1 Jul 2014 at 13:13

PhysicsMan94 said:
Whatever the case, this quote from a different thread is very apt:

After the release of Mantle I saw lots of pro-AMD guys on this forum suddenly talking crap about Microsoft and saying how bad DirectX is (even though that's the API which has been driving PC gaming for the past goodness knows how long). With the issue highlighted in this thread it is becoming clear that Microsoft do actually know what they are doing and their huge amount of experience with API development and memory management means that they create software based products which are very efficient regarding hardware resources.

AMD have a long way to go with Mantle...

I have always been talking crap about DirectX, its always been crap.

Martini1991 · 1 Jul 2014 at 13:22

humbug said:
I have always been talking crap.

Although I'm not sure how anyone can have always been calling DirectX crap, given it's been all we've had for like the past many years.

keysersoze · 1 Jul 2014 at 13:32

ubersonic said:
So basically they implemented DX11, badly. Then added Mantle, badly. Maybe just focus on one API next time DICE lol, or spend more time/money so at least one works properly

No... they haven't implemented DX11 badly. They have a reasonably big engine team at Frostbite (no longer DICE), with some very clever programmers especially for Rendering.

Sin_Chase · 1 Jul 2014 at 13:42

humbug said:
I have always been talking crap

+1

PhysicsMan94 · 1 Jul 2014 at 13:50

humbug said:
I have always been talking crap about DirectX, its always been crap.

Well, I'm not surprised with you really.

GoogalyMoogaly · 1 Jul 2014 at 13:54

I think some AMD people at one point liked DirectX so much they bought Win8 just to get DirectX 11.2. They paid money for it, that's howm uch they liked it1

ubersonic · 1 Jul 2014 at 14:11

humbug said:
I have always been talking crap about DirectX, its always been crap.

True, the only reason Direct3D surpassed OpenGL a decade ago is because Microsoft threw money at FUD and developers, it didn't actually become better than OpenGL until some time after (due to OpenGL support and thus development dropping off).

keysersoze said:
No... they haven't implemented DX11 badly.

Their implementation was buggy at launch (don't know if it still is, I stopped playing due to that) and badly optimised.

~Mike~ · 1 Jul 2014 at 14:22

GoogalyMoogaly said:
I think some AMD people at one point liked DirectX so much they bought Win8 just to get DirectX 11.2. They paid money for it, that's howm uch they liked it1

That they did. I remember one particular chap who kept on about having dx 11.2 because he got win 8 and trying to convince others to do the same.

keysersoze · 1 Jul 2014 at 17:44

ubersonic said:
Their implementation was buggy at launch (don't know if it still is, I stopped playing due to that) and badly optimised.

No. The issues you've seen have for the most part been Battlefield game implementation issues, rather than Frostbite issues. Decisions related to design both in game play and technical. The Frostbite engine team is separate from the DICE team that makes Battlefield, they're not even in the same building any more.

Disco_P · 1 Jul 2014 at 18:13

keysersoze said:
No... they haven't implemented DX11 badly. They have a reasonably big engine team at Frostbite (no longer DICE), with some very clever programmers especially for Rendering.

I seem to remember getting more Direct X errors in BF4 than kills.

As for mantle they need to make it better and do it fast. It's a hard sell as it is with developers having to develop something for only a small consumer base and consumers buying into it for only a few games to support it.

And now with this increased VRAM usage and lower than expected frame rate gains compared to DX11 makes it worse. What about when DX12 comes around?

It needs a killer app - BF4 probably only made it worse. Star Citizen could be it, though it might not. We'll see.

Final8y · 1 Jul 2014 at 18:21

Disco_P said:
I seem to remember getting more Direct X errors in BF4 than kills.

As for mantle they need to make it better and do it fast. It's a hard sell as it is with developers having to develop something for only a small consumer base and consumers buying into it for only a few games to support it.

And now with this increased VRAM usage and lower than expected frame rate gains compared to DX11 makes it worse. What about when DX12 comes around?

It needs a killer app - BF4 probably only made it worse. Star Citizen could be it, though it might not. We'll see.

There is a lot more to it than frame rate gains and depending on the setup it can be significant.

In my case its the lack of frame rate loss as i Vsync and the smoothness is more than enough for me.