AVX2 and FMA3 in games

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superstition

Platinum Member
Feb 2, 2008
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If you want to measure the impact of new instructions, you have to use the same compiler for all of the builds or you are creating distortions.
More data is less of a distortion than less. Using just one compiler lacks the information in terms of how well the compiler implements those instructions versus the others.
 

Nothingness

Platinum Member
Jul 3, 2013
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More data is less of a distortion than less.
That's so wrong, I don't know where to start and if it's worth explaining...

Using just one compiler lacks the information in terms of how well the compiler implements those instructions versus the others.
That's another discussion, but given what you wrote just above I won't waste my time.
 

itsmydamnation

Platinum Member
Feb 6, 2011
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So the answer is no. Thanks for stopping by in this topic to provide this understanding and learning.
Ok here you go, i refer you to the previous posts you ignored completely :

https://forums.anandtech.com/thread...ecture-details.2465645/page-149#post-38667262
https://forums.anandtech.com/threads/summit-ridge-zen-benchmarks.2482739/page-157#post-38648539
https://forums.anandtech.com/threads/summit-ridge-zen-benchmarks.2482739/page-155#post-38647189

Its not instructions, its not compilers, its not programmers.

its the synergy (shudder) off all of them together and having all three aligned. What you fail to understand is what it costs to do that, even for just one product targeting one platform.

I told you to go build an old version of blender compiling against all the latest instructions for a reason, you choose to ignore it, it would have shown you something........
 

superstition

Platinum Member
Feb 2, 2008
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its the same difference, the fact you dont see that is mind boggling.
What I see is someone who stopped by this thread to post a flaming call out, with no interest in furthering the discussion that was happening in prior pages. I'm not going to respond to your posts until you stop being rude. I told you that before, now that I recall, and this time I'm not going to make more effort to remember that promise. Don't be rude and maybe we can have a good discussion.

If you have something specific and non-jerky to say about this topic directly then I, for one, am interested.
 
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itsmydamnation

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Feb 6, 2011
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What I see is someone who stopped by this thread to post a flaming call out, with no interest in furthering the discussion that was happening in prior pages. I'm not going to respond to your posts until you stop being rude. I told you that before, now that I recall, and this time I'm not going to make more effort to remember that promise. Don't be rude and maybe we can have a good discussion.
So i gave you what you wanted and that wasn't good enough.

Want me to find and replace Blender for Game for you and repost, will that make you happy?
 
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superstition

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Feb 2, 2008
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So i gave you what you wanted and that wasn't good enough.

Want me to find and replace Blender for Game for you and repost, will that make you happy?
For the last time, what will make me happy is for you to stop being rude. If that's not clear at this point there is no reason for me to respond to your posts.
 
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itsmydamnation

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For the last time, what will make me happy is for you to stop being rude.
Blunt and rude are two different things, i spent a large amount of time explaining the situation, about how hard the things you talk about are , to think about effort costs for doing so and you just ignored all of it.

Its not like you came up with completing counter points, you just ignored because you didn't like the answer.

So who is rude?
 
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itsmydamnation

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People in tech forums who brag about being blunt are invariably rude. It is a euphemism.

I ignore rude communications. Most people do.
Yes when the people who take time to explain things to you all get frustrated with you it all their fault? I'm not the only one.

But note through all of this you never once address the technical points raised, not in that thread, not since being linked in this thread.

funny that!
 
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superstition

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Feb 2, 2008
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Let me know when you plan to post something on-topic here. Until then I am definitely not going to play your game anymore.

And before you claim that you have, make sure your post has something directly to do with those instructions and doesn't call me out or try to continue an argument I left behind in another topic. That would be a good start.

This, which was your start, was not a good one.
 
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itsmydamnation

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Let me know when you plan to post something on-topic here. Until then I am definitely not going to play your game anymore.

And before you claim that you have, make sure your post has something directly to do with those instructions and doesn't call me out or try to continue an argument I left behind in another topic. That would be a good start.

This, which was your start, was not a good one.
I see complete avoidance of the technical points raised

Maybe you should go read John Carmacks commentary on Rage's game engine development (ID tech 5), where he started again from scratch, up until then ID tech 4 still had original Quake Code in it.

You'll probably ignore that because it doesn't tell you want you want to hear.................
 
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ozzy702

Golden Member
Nov 1, 2011
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Bumping this abortion of a thread because I'm playing around with my 8700k and am curious what impact using a large avx offset will do in gaming. What games are currently using AVX?
 

NostaSeronx

Diamond Member
Sep 18, 2011
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What games are currently using AVX?
Anything created post-2015 and is in the Windows Store. Those are guaranteed to be either "SSE2" or "AVX2", in 128-bit vectors. In standard apps, AVX/AVX2 generally is used in a separate exe file, in which if Intel Physics it will always be 256-bit (Smoke, Cloth, etc). The big game engines do support AVX since 2015, UE4/Gamebyro(Oblivion/FO3/etc can be modified to support AVX)/etc.
 

Jan Olšan

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Jan 12, 2017
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You thing AVX/AVX2 gets used just because the compiler targets it? You have a huge confidence in autovectorizers.
 
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MajinCry

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Jul 28, 2015
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Anything created post-2015 and is in the Windows Store. Those are guaranteed to be either "SSE2" or "AVX2", in 128-bit vectors. In standard apps, AVX/AVX2 generally is used in a separate exe file, in which if Intel Physics it will always be 256-bit (Smoke, Cloth, etc). The big game engines do support AVX since 2015, UE4/Gamebyro(Oblivion/FO3/etc can be modified to support AVX)/etc.

Fwiw, all x64 games have a hard requirement for SSE2.

Gamebryo doesn't do AVX (Fallout 4 or Skyrim SE might, but I doubt it). In fact, the older Gamebryo games from Bethesda have a significant amount of x86-87 instructions, despite equivalent SIMD instruction sets providing much better performance for the same result. The [NVAC mod](https://www.nexusmods.com/newvegas/mods/53635/?) replaces specific instructions with their newer counterparts.

What do you mean by "Intel Physics"? Can't find any Intel middleware for that.
 

Carfax83

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Nov 1, 2010
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What do you mean by "Intel Physics"? Can't find any Intel middleware for that.

He probably means Havok physics engine, which was purchased by Intel years ago. It's the main contender for PhysX, which definitely uses AVX for cloth simulation. Other games that definitely uses AVX are Path of Exile which they use for particle effects, and Project Cars 2.

AVX and AVX2 will be in much greater use in the next console cycle, provided that they use Ryzen CPUs, and all indications point in that direction. Is it possible that NVidia and AMD's drivers use AVX/AVX2?
 

MajinCry

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Jul 28, 2015
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He probably means Havok physics engine, which was purchased by Intel years ago. It's the main contender for PhysX, which definitely uses AVX for cloth simulation. Other games that definitely uses AVX are Path of Exile which they use for particle effects, and Project Cars 2.

AVX and AVX2 will be in much greater use in the next console cycle, provided that they use Ryzen CPUs, and all indications point in that direction. Is it possible that NVidia and AMD's drivers use AVX/AVX2?

Aah, didn't know that Havok was bought by Intel. It was bought by Microsoft in 2015.

I don't see how the drivers would benefit from AVX code. The bulk of the driver work is draw calls, which involves making sure everything is fine and dandy before rendering the next object. But then again, I don't know how it would not benefit.

We need someone like Zlatan to weigh in on this.
 

Dufus

Senior member
Sep 20, 2010
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Bumping this abortion of a thread because I'm playing around with my 8700k and am curious what impact using a large avx offset will do in gaming. What games are currently using AVX?

From my experience with AVX2 on Xeon HSW-E and from AF's blog AVX2 execution units are in a powered down state and only starts to come live when an AVX2 instruction is received. It takes time for the AVX2 EU's to be woken up so slower 128bit registers used until online (AVX2 registers are 256bit). An AVX2 multiplier can be in effect too, technically though on BDE it is really a multiplier limit, not an offset). This AVX2 multiplier offset lasts for about one millisecond after the last AVX2 instruction. This means if only using a few AVX2 instructions now and then, it could actually hurt performance. Inversely with lots of AVX2 use it doesn't help to run AVX2 on more than one thread of the same core (HTT) at the same time as performance degradation can take place.

Don't know if things have changed any for CFL.