Demystifying DirectX 12 <{ExtremeTech}>

[ocre]

I havent seen this posted and i think we are all pretty interested in DX12.

http://www.extremetech.com/extreme/...what-amd-intel-and-nvidia-do-and-dont-deliver

The situation is pretty confusing, probably more so to people who have been through several DX updates in the past. PC gaming today is so much better than it ever has been in the past (my opinion).

Anyway, some highlights

-When Windows 10 debuts next month, it&#8217;s going to deliver the first full DirectX update since Windows 7 debuted six years ago.

-There is a lot of confusion

- Intel, Nvidia, and AMD all support DirectX 12 at various feature levels, and no GPU on the market today supports every single optional DirectX 12 capability.

-DirectX feature levels and point updates are not the same thing

-A DirectX feature level, in contrast, defines the level of support a GPU gives while still supporting the underlying specification.

So basically, the most important thing to me is not so much who supports what but......i will just quote the article:

The purpose of the feature level function is to allow developers to target a single API rather than developing separate codebases in parallel to ensure that a game can run smoothly on multiple generations of GPU hardware rather than writing separate code for DX12, DX11, DX10, and so on.

so the article tries to clear up some of the confusion in feature levels on various graphics adapters but i will jump past that to what i think is the biggest value to us all

Why DirectX 12 looks the way it does

One common concern from gamers is that if their cards only support DirectX 12 11_1 or 12_0, they&#8217;ll miss out on what DirectX 12 has to offer. It&#8217;s important to remember that the multi-threading and multi-GPU capabilities of DirectX 12 that we&#8217;ve seen previewed to-date (and demonstrated via Mantle) are still completely available to every feature level. Kepler and older GCN GPUs will absolutely benefit from the new capabilities DirectX 12 delivers. With that said, there are some specific capabilities baked into DirectX 12_0 and 12_1 that gamers with older cards won&#8217;t have access to &#8212; but as the charts above show, this isn&#8217;t a problem unique to AMD, Nvidia, or Intel. No current Intel IGP supports DirectX 12_0, while only Nvidia&#8217;s Maxwell hardware supports 12_0 or 12_1.

and this is a big deal. See, DX12 could be quickly adopted. Faster than others in the past, which were slow..... too slow.
so some more from the article

To understand why Microsoft built DirectX 12 the way it did, consider the alternative. Prior to DirectX 11, every new DirectX version was tied to new hardware requirements. From time to time, AMD or Nvidia might implement a specific feature in hardware before it became part of a future DirectX standard, but graphics cards were fixed to the DirectX APIs they supported at launch. Without the flexibility afforded by feature levels, the only gamers who could take advantage of DX12 would be those who purchased either a GCN 1.1, 1.2, or Maxwell GPU. Everyone else, including the millions of people with slightly older cards, would&#8217;ve been left out in the cold.

Adding feature levels and implementing them as part of DX12 means that millions of people will see significant benefits from adopting the new API in the here and now. No, older GPUs may not support every single DX12 feature, but no one is going to end up having to choose between a game that looks great in DX11 or a half-assed DX12 version due to graphics card implementation issues. When AMD, Nvidia, and Intel talk about supporting DirectX 12 on older hardware, they&#8217;re talking about the features that matter most &#8212; lower-overhead APIs, better CPU utilization, and multi-GPU functionality. The actual feature levels that define 12_1 as being different from 11_0 are interesting and useful in certain scenarios, but they aren&#8217;t the capabilities that will truly shape how gamers experience gaming with the API

I know we argue back and forth a lot and nitpick over details but I think the biggest aspect of DX12 is how flexible it is. I think it will be adopted much faster than any other version.

Just wanted to share my opinion on what i think matters most but the article is here to discuss.

 

[DaveSimmons]

When AMD, Nvidia, and Intel talk about supporting DirectX 12 on older hardware, they&#8217;re talking about the features that matter most &#8212; lower-overhead APIs, better CPU utilization, and multi-GPU functionality

I suspect the developers of engines like Unity, Unreal, etc. will concentrate on these performance improvement features first.

The huge FPS increase in synthetic tests on old cards means the game can include much higher DX 11 or DX 9 style image quality on a given old card and CPU.

Using new features that almost no cards support will be a lower priority.

I think the speed of DX 12 adoption will depend on whether or not MS forces us to upgrade to Windows 10 to use it. The upgrade is free, but many people hate 8.x and aren't in any hurry to move on from 7.

 

[waffleironhead]

"No current Intel IGP supports DirectX 12_0, while only Nvidia&#8217;s Maxwell hardware supports 12_0 or 12_1."
Except their chart shows gcn 1.1 is 12_0 compliant.

 

[chimaxi83]

Thanks for pushing MS to finally update DirectX, AMD/Mantle!

 

[ShintaiDK]

"No current Intel IGP supports DirectX 12_0, while only Nvidia&#8217;s Maxwell hardware supports 12_0 or 12_1."
Except their chart shows gcn 1.1 is 12_0 compliant.

Its filled with errors and missing parts. Kepler also listed as 11.1, Maxwell(v1) is listed as 12.0. both are 11.0 parts. GCN 1.2 not even listed.

The article is simply sloppy work, direct for the trashcan.

 

[waffleironhead]

Its filled with errors and missing parts. Kepler also listed as 11.1, Maxwell(v1) is listed as 12.0. both are 11.0 parts. GCN 1.2 not even listed.

The article is simply sloppy work, direct for the trashcan.

Might be easier to remove the "De" from the article title than editing the rest.

 

[Headfoot]

A little bummed they left off gcn 1.2 in the chart, still a good article for the basics of the situation

 

[ocre]

I suspect the developers of engines like Unity, Unreal, etc. will concentrate on these performance improvement features first.

The huge FPS increase in synthetic tests on old cards means the game can include much higher DX 11 or DX 9 style image quality on a given old card and CPU.

Using new features that almost no cards support will be a lower priority.

I think the speed of DX 12 adoption will depend on whether or not MS forces us to upgrade to Windows 10 to use it. The upgrade is free, but many people hate 8.x and aren't in any hurry to move on from 7.

So, I have heard windows 10 was a free upgrade for win8 and 7 owners. Its part of my excitement and just another reason I think dx12 could be adopted faster than most DX versions have.


http://www.pcworld.com/article/2873...a-free-upgrade-for-windows-7-and-8-users.html

That still doesn't mean it will happen overnight. But I think there is a chance dx12 moves quicker and that is a fantastic thought for me.

 

[bystander36]

I think some of you are missing the point. The point is, DX12 has the ability to be used with most all recent cards, it just will miss certain features on cards which lack the ability to use them. DX12 is not an all or nothing API like previous DX versions.

 

[RoarTiger]

I thought this was the money quote

"Just as there are very few games that require DirectX 11.2 or 11.1 (offhand, I can&#8217;t think of any) there are going to be very few DirectX 12 titles that mandate DirectX 12 FL 12_0 or 12_1. I&#8217;m not saying such games will never happen, but that&#8217;s going to be years from now, long after current GPUs have been replaced by modern hardware."

Arguing about the high level feature levels different manufacturers use on current gen cards is basically useless since the current gen cards will be replaced long before any games utilize them. Enjoy the upcoming Win 10 standard DX12 benefits no matter what you buy today and dont base your purchase decision on features that likely wont be used in the lifetime of your GPU.

 

[biostud]

I'm really looking forward to what dx12 can do for multi gpu.

 

[master_shake_]

I'm more interested to see the mixing of GPUs.

Is it just the horsepower or is it everything?

Can I finally use physx with an AMD in my system?

 

[AnandThenMan]

Can I finally use physx with an AMD in my system?

Nvidia still has to supply a driver meaning they can hardware ID check as they do now. So no.

 

[soccerballtux]

no GPU on the market today supports every single optional DirectX 12 capability.

mmmm yeah we knew that

 

[night.fox]

as others mentioned, I am more interested as well on what dx12 can offer for multi-gpu. Can I crossfire old and new? Meaning if I have R9 290x, can I just buy the highest AMD like the fury and just crossfire them.

or if you have 780ti or 780, can just buy 980ti and sli them.

This will be great so dont have to upgrade all the time and just keep the latest gpu on the first slot and the remaining old gen cards are just there to give some "boost" when needed

 

[TheELF]

as others mentioned, I am more interested as well on what dx12 can offer for multi-gpu. Can I crossfire old and new?

Yeah,you wish it where that easy,you can put different gpus into a system but it will be down to each game to take advantage of those gpus.
Just like you get different sli profiles for each game,only now it will be even more specific because it will have to be in the game code.
https://www.youtube.com/watch?v=9cvmDjVYSNk
(Yeah games that can't keep 30fps with an 290x ,don't expect too many of those to pop up)

 

[ocre]

I can't wait to upgrade my x58 to windows 10. But i am kind of conflicted. This will be the 3rd Windows OS, not counting the various Linux versions I don't even boot up anymore.

I am just not sure how I will do this one. I usually just buy another HD and keep my old OS on my old drive. I change simply change the boot drive and boot whatever OS I want. But, this time I am not sure if I will keep win 8.1 at all. I just hate having to re download everything, reinstall everything, re setup everything...... It is enough to make me want to hold off for a little while. Unless there are dx12 games coming real soon, not sure there is any other major reason to rush into windows 10.

I guess I need to wait to see how stuff perfoms on win10 at launch. Perhaps there will be some surprises

 

[PrincessFrosty]

Having optimisations in DirectX that everyone can take advantage of is a good thing.

However I don't think flexibility for features is necessarily a good thing, I think having the push to want to upgrade your GPU for new features is a good thing, it keeps people invested in the PC space and keeps pushing new graphics and features.

It would have been better if they'd just released a succession of new DirectX's, so DirectX 12 at launch by default which has all the optimisations in it, then a DirectX13 with a suite of new graphical capabilities. Then video card manufacturers can target their support/features to specific levels and that makes marketing and consumer choices easier to make. I forsee this being a huge source of controversy with regards to who supports what and nothing but confusion, headache and a mess of expectations for gamers who want to upgrade.

 

[bystander36]

The difference with DX12 is they can still add in those new features, and you'll still need to buy a new card to use them, but if you do not upgrade for new features, you will still use DX12, just without the new features.

It makes things easier on the dev's. They no longer have to build a DX9 and DX11 version. Everyone uses DX12, but some will have certain features disabled.

 

[Azix]

Asynchronous shaders seems like it will be a big deal for AMD compared to everything before maxwell 2. How much effort does it take to use that feature? Automatic? Because for guys with 7000s to 290s this could be really nice for performance

 

[geoxile]

Asynchronous shaders seems like it will be a big deal for AMD compared to everything before maxwell 2. How much effort does it take to use that feature? Automatic? Because for guys with 7000s to 290s this could be really nice for performance

Definitely not automatic. Mantle had the same feature and it was never used.

 

[Noctifer616]

Asynchronous shaders seems like it will be a big deal for AMD compared to everything before maxwell 2. How much effort does it take to use that feature? Automatic? Because for guys with 7000s to 290s this could be really nice for performance

Only Thief used it and I think it might only work in crossfire. So yea, devs are lazy.

 

[Despoiler]

Definitely not automatic. Mantle had the same feature and it was never used.

I don't think that is indicative of the feature's usefulness. The devs working with Mantle were just trying to get the base functionality implemented and usable. Working through all of the bugs being alpha and beta testers doesn't allow a wide feature scope. Now that they are well familiar with Mantle and all of its forks, we will see a wider set of features implemented.

 

[ocre]

Having optimisations in DirectX that everyone can take advantage of is a good thing.

However I don't think flexibility for features is necessarily a good thing, I think having the push to want to upgrade your GPU for new features is a good thing, it keeps people invested in the PC space and keeps pushing new graphics and features.

It would have been better if they'd just released a succession of new DirectX's, so DirectX 12 at launch by default which has all the optimisations in it, then a DirectX13 with a suite of new graphical capabilities. Then video card manufacturers can target their support/features to specific levels and that makes marketing and consumer choices easier to make. I forsee this being a huge source of controversy with regards to who supports what and nothing but confusion, headache and a mess of expectations for gamers who want to upgrade.

thats is interesting. But, in the past it seemed to slow down progress.

I am not sure. There are immediate and huge gains to be had right off the bat. I am sure some of the feature level stuff will take time to roll out. Honestly, does those feature levels justify a whole new DX? I believe many of them can be emulated anyway. It seems like busting up the roll out, it just would be its own can of worms.

I can see the pros and cons in both. I am leaning towards the route M$ is taking on this one.......which is kind of rare of me.

 

[Makaveli]

I'm more interested to see the mixing of GPUs.

Is it just the horsepower or is it everything?

Can I finally use physx with an AMD in my system?

i've been doing it without dx 12 for over a year now.

Will have to see if it still works in windows 10.