Oculus Employees: "Preemption for context switches is best on AMD, Nvidia possibly catastrophic"

fs123 · 5 Sep 2015 at 16:29

Now as Microprocessor analyst, David Kanter, said, some Oculus employees told him that the best Preemption support for context switches was with AMD by far, Intel was pretty good and NVIDIA was possibly catastrophic (1:21:00 in the video below).

http://www.dsogaming.com/news/oculus-employees-preemption-for-context-switches-is-best-on-amd-nvidia-possibly-catastrophic/

An interesting interview shedding more light into DX12 'pre-emption' for context switching of shaders. Slow context switching leads to poor latency which is bad for VR.

Rroff · 5 Sep 2015 at 16:36

Its not something that has been a big focus until very recently - nVidia managed to get pre-emption working for compute stuff in general (on hardware that theoretically shouldn't support it at all) but last I heard they hadn't addressed the situation with dynamic parallelism (which is relevant to async) but I wouldn't count them out when it actually comes to it being needed. (EDIT: Its also currently only enabled for debugging use AFAIK so it won't perform well in gaming use as things stand).

As is often the case AMD has been focusing on forward thinking and how things "should" be done and nVidia concentrating on the actual here and now requirements - which probably gives AMD a little head start with DX12 but they'll probably be focusing on "DX13" at the expense of DX12 when DX12 is properly a thing :S

EDIT: End of the day Maxwell is going to be a liability when it comes to DX12, its been savaged to be very good at DX11 and that is it but anyone who really cares about DX12 performance won't want to be on any of the current GPUs if developers actually make proper use of what DX12 can bring to the table (i.e. AMD supported tessellation when nVidia didn't at all and we all know what happened there).

Gregster · 5 Sep 2015 at 16:54

Good that AMD have the ability to run this "as is" and looks like Nvidia users will probably need to upgrade to Pascal to get the best results. More Nvidia sales and AMD users can carry on with their older hardware. Good find and I skipped most but watched from the 1 hour mark and found it interesting thanks

shankly1985 · 5 Sep 2015 at 17:01

All this VR makes me really want to give it a try.
It's great that amd is always leading the way.

Dave2150 · 5 Sep 2015 at 17:16

Gregster said:
Good that AMD have the ability to run this "as is" and looks like Nvidia users will probably need to upgrade to Pascal to get the best results. More Nvidia sales and AMD users can carry on with their older hardware. Good find and I skipped most but watched from the 1 hour mark and found it interesting thanks

I love how you try and turn this into a positive thing for NVIDIA. "More sales for NVIDIA" - yeh clearly they deserve it.

All those 980TI owners who'll be at a disadvantage in DX12 games will surely be over the moon and will be eager to spend another £500 for NVIDIA's next GPU.

Gregster · 5 Sep 2015 at 17:21

Dave2150 said:
I love how you try and turn this into a positive thing for NVIDIA. "More sales for NVIDIA" - yeh clearly they deserve it.

All those 980TI owners who'll be at a disadvantage in DX12 games will surely be over the moon and will be eager to spend another £500 for NVIDIA's next GPU.

Really? You picked that from my post? Grow up!

Marine-RX179 · 5 Sep 2015 at 17:25

Dave2150 said:
I love how you try and turn this into a positive thing for NVIDIA. "More sales for NVIDIA" - yeh clearly they deserve it.

All those 980TI owners who'll be at a disadvantage in DX12 games will surely be over the moon and will be eager to spend another £500 for NVIDIA's next GPU.

Actually 980Ti seem to quite well on dx12, but for the lesser Maxwell that were mid-range cards but got pimped up and sold as high-end, well they don't seem to be coping too well comparing to their direct competition cards.

So basically anyone that must buy Nvidia, they should most definitely save up and get the 980Ti (considering it is actually a decent bang for bucks card)...and if they really can't push their budget that high, then they should go for a 390/390x, rather than going 970/980...

Ian Evey · 5 Sep 2015 at 17:29

By the time vr is mainstream and worth it we will all be 5 years older, I doubt the preemption context switching will be a problem by that time.

whyscotty · 5 Sep 2015 at 17:46

Dave2150 said:
All those 980TI owners who'll be at a disadvantage in DX12 games will surely be over the moon and will be eager to spend another £500 for NVIDIA's next GPU.

And what games are these?

Ash0787 · 5 Sep 2015 at 18:10

Oculus are quite open, they will probably tell us how they intend to deal with the situation like will they disable the feature or not, I heard it was beneficial to one of their algorithms 'async timewarp'

razorpakk · 5 Sep 2015 at 18:20

Keep reading about AMD being great for DX12 and VR. It's all in the future, all in promises and maybes.

It is important to think about the future, I get it, but I only care about today.
Even fury barely exist.

When VR comes out and a decent game is programmed for it, then maybe those words will be worth something.

fs123 · 5 Sep 2015 at 18:54

If what the Occulus guys say is true then Maxwell cards may start struggling when more games start using Async algorithms. It could result in poor performance in a years time so is it really a wise investment when spending £500+ now? Could you potentially lose a lot of resale value in just a year?

IF Nvidia do get people to upgrade due to the current cards not supporting DX12 fully, how many would go back to a company which shafted them with their last cards?

Questions are being raised but some diehard Nvidia guys can still put a positive spin on it.

Dicehunter · 5 Sep 2015 at 18:57

Just give me an Oculus Rift so I can play Alien Isolation again but this time not just soil my pants but have a heart attack as well

shankly1985 · 5 Sep 2015 at 18:58

Dicehunter said:
Just give me an Oculus Rift so I can play Alien Isolation again but this time not just soil my pants but have a heart attack as well

Nooo, Nooo That game was tense enough haaa

razorpakk · 5 Sep 2015 at 18:58

fs123 said:
If what the Occulus guys say is true then Maxwell cards may start struggling when more games start using Async algorithms. It could result in poor performance in a years time so is it really a wise investment when spending £500+ now? Could you potentially lose a lot of resale value in just a year?

IF Nvidia do get people to upgrade due to the current cards not supporting DX12 fully, how many would go back to a company which shafted them with their last cards?

Questions are being raised but some diehard Nvidia guys can still put a positive spin on it.

I like to think I'm pretty open about things, but I still can't fault Nvidia.

Is there a triple A DX12 game (by that I mean something where the extra performance matters) available or even announced?

varkanoid · 5 Sep 2015 at 18:58

I say again not interested in VR till it resembles a Star Trek holodeck !

humbug · 5 Sep 2015 at 18:59

Oh........dear.

Dicehunter · 5 Sep 2015 at 19:00

shankly1985 said:
Nooo, Nooo That game was tense enough haaa

I've actually played Alien Isolation on a work mates rig with his Oculus Rift DK2 and it was amazing, It might sound cliche but it honestly feels like you're there especially if the sound setup is good

savagesam117 · 5 Sep 2015 at 19:01

I'm not interested in Oculus as it makes me feel really ill when using it but it's good to see that they are actually addressing both sides. I don't see VR working properly for a good few years yet a bit like DX12.

Gregster · 5 Sep 2015 at 19:29

Dicehunter said:
I've actually played Alien Isolation on a work mates rig with his Oculus Rift DK2 and it was amazing, It might sound cliche but it honestly feels like you're there especially if the sound setup is good

I played in Nvidia 3DVision..... For less than 5 mins before saying "**** that!" and turning it off