Does DCS World support SLI

[Fish]

Title says it all.....?

 

UPDATE 2012.12.08

 

Very pleasant surprise.

 

Ok I have got SLI to work with DCS world, A10 on a single monitor. I downloaded the most recent beta drivers from NVIDIA, 310.70, switched off vsynch, so i could see frames, and ran a quick test over Tblisi, with

no video on pit mfd's,

 

everything max, except,

traffic, low

clutter 0,

trees 6k

Tree shadows off.

 

Frames No SLI 54

Frames SLI 80

 

Please note that this is a quick test, and i will set up some kind of bench and get a better average result. Also note that the actual fps are not relevant because all systems are different, but, i can say with certainty that there is a SIGNIFICANT boost to frames using SLI.

 

Below are some setting information which i hope will help others.

 

 

 

Edited December 8, 2012 by Fish

[Heli Shed]

AFAIK no.

 

it doesn't even support multiple cores (sound on one other core is hardly multi core threading).

 

perhaps soon?

 

DX11?

 

Hope all is well.

 

'T'

[sobek]

it doesn't even support multiple cores (sound on one other core is hardly multi core threading).

 

That is exactly what it is.

[Risk]

Do you think SLI and multicore development will ever become transparent to developers so they don't have to code proprietary software to take advantage of it?

[EtherealN]

"Multicore development" is already "transparent".

 

Issue is that it is not exactly easy - and transforming an existing, singlethread codebase is even less so. It is, as they say, about as far as it is possible to get from the proverbial flipping of a compiler flag; it's something you want to do at the design stage not after implementation is already complete.

[BIGNEWY]

I am not sure how relevant this is for you

 

but I used to have a crossfire ATI setup, and dcs would not see both cards memory.

 

but when I used it in conjunction with SoftTH it would use all of the memory from both cards.

 

May be worth a look ?

[EtherealN]

Bignewy, SLI and Crossfire will, by definition, not add the memory on the two cards together.

 

If you have two cards with 1GB vRAM each in SLI or crossfire, this does not mean you have 2GB of vRAM available to you. It means you have 1GB of it, because both cards in such a configuration operate on exactly the same data and both need to have that same data in their own memory banks. Typically one card acts as a sort of master, the other as a slave, and the "master" hands over part of the work to the slave.

 

SoftTH I don't know all that well though, so cannot comment on how that operates.

[BIGNEWY]

Sure I am not up to date with the technical aspects of it, all I know is I had better performance from my crossfire setup when using softTH, and also noticed DCS using more memory from my cards.

 

I am sure someone with more knowledge will put me right :)

[Quirkitized]

You will not get 100% addition performance, but it can help. SLI works in full screen for DCS, it will not work in windowed mode.

 

If you plan to use multiple monitors for gauges, mfds, etc, then you will need to disable sli in dcs profile or your framerate will be in the single digits. However if you plan to triple screen, fullscreen with SLI, then it'll work.

[EtherealN]

Sure I am not up to date with the technical aspects of it, all I know is I had better performance from my crossfire setup when using softTH, and also noticed DCS using more memory from my cards.

 

I am sure someone with more knowledge will put me right :)

 

Actually, it's probably quite sensible since Crossfire does not support DCS, AFAIK.

 

It's one of those cases where AMD has to support DCS, it's not enough for DCS to be made with crossfire in mind. For that reason, I would not be surprised at all if you get better performance with SoftTH than crossfire. Though of course, I don't use either of those two myself, so I don't keep a very close eye on them so thing may change there without me being aware.

[BIGNEWY]

I gave up in the end with crossfire, I was on to the ATI forums daily for assistance, but it was futile :)

I am more than happy with one card now.

Edited November 29, 2012 by BIGNEWY

[SinCityJet]

You will not get 100% addition performance, but it can help. SLI works in full screen for DCS, it will not work in windowed mode.

 

If you plan to use multiple monitors for gauges, mfds, etc, then you will need to disable sli in dcs profile or your framerate will be in the single digits. However if you plan to triple screen, fullscreen with SLI, then it'll work.

 

DCS World uses both of the Nvidia 570 GPUs I have in SLI, using current beta drivers from Nvidia and using the DCS:BS SLI profile which can be found in the Nvidia settings.

 

If you have two identical Nvidia cards and a motherboard which will support them, give SLI a try.

[JG14_Smil]

Hello, I ran two Nvidia 680 GTX's for some time with several multi-monitor combos. I had great FPS and no issues at all until I went with a large PLP setup. I had some stutters then..

[BHawthorne]

SLI and Crossfire is all based on gaming profiles as to how it occurs and what settings it uses. If there is no profile available, it'll use the default profile. Most people have their setup default ad single GPU profile, not SLI/Crossfire. You can manually make a game profile for DCS though.

 

People always confuse the words support and work. Something might not be supported but it could work. In those cases you have to figure it out on your own manually though.

[Geert Hooghe]

Bignewy, SLI and Crossfire will, by definition, not add the memory on the two cards together.

 

If you have two cards with 1GB vRAM each in SLI or crossfire, this does not mean you have 2GB of vRAM available to you. It means you have 1GB of it, because both cards in such a configuration operate on exactly the same data and both need to have that same data in their own memory banks. Typically one card acts as a sort of master, the other as a slave, and the "master" hands over part of the work to the slave.

 

SoftTH I don't know all that well though, so cannot comment on how that operates.

 

I have read somewhere on this forum an answer from an ED Tester that mainly the C PU and not the G PU is under pressure when flying eg. near a town or harbor.

 

IMHO this means that you better get an INTEL i7 processor with lots of RAM than a videocard with 4 GB !!

 

Correct ??

[pepin1234]

I am not sure how relevant this is for you

 

but I used to have a crossfire ATI setup, and dcs would not see both cards memory.

 

but when I used it in conjunction with SoftTH it would use all of the memory from both cards.

 

May be worth a look ?

 

 

how many monitors do you have??

[EtherealN]

I have read somewhere on this forum an answer from an ED Tester that mainly the C PU and not the G PU is under pressure when flying eg. near a town or harbor.

 

IMHO this means that you better get an INTEL i7 processor with lots of RAM than a videocard with 4 GB !!

 

Correct ??

 

Possible bottlenecks when flying low over/near a town:

 

CPU

GPU

RAM amount

vRAM amount

vRAM bus

 

Everything depends on what the configuration is.

[Heli Shed]

That is exactly what it is.

 

No it's not.

 

What it is is using one core for sound the other core for the sim. Any remaining cores are redundant / working on background tasks. For it to be truly multi-threading, all cores would be used for all tasks.

 

'T'

[Heli Shed]

I have read somewhere on this forum an answer from an ED Tester that mainly the C PU and not the G PU is under pressure when flying eg. near a town or harbor.

 

IMHO this means that you better get an INTEL i7 processor with lots of RAM than a videocard with 4 GB !!

 

Correct ??

 

Correct.

[EtherealN]

For it to be truly multi-threading, all cores would be used for all tasks.

 

Completely incorrect.

 

Multi-threading is multithreading. It is when one process executes in multiple threads. DCS does qualify under this. At no point short of something like Folding@Home or something like your GPU preparing a screenframe would all cores be used for all tasks. It simply doesn't happen.

 

Example from a fairly multithreaded simulator: Rise of Flight. It has graphics in one thread, sound in one, AI in one, phsyics in one. It then distributes these across the available resources, but at any one time any one task will only be taking place in one specific thread and thereby only on one specific core. This does have the effect that you will not typically "max out" almost any CPU with almost any game, multithreaded or not, since by the nature of what they are different natural partitions will place differing demands on execution resources and you'll likely always have one of them bottlenecking your execution for one reason or another.

 

Multithreading computer games is a very difficult proposition that requires careful management of data dependencies, the most common one (indeed the only one I've ever seen) is to segregate distinct parts of a given game engine into separate parts just like RoF does.

[sobek]

Correct.

 

I'd say partially. With the inclusion of more and more advanced effects(shadows, reflections, HDR, etc.), the strain on the GPU is increasing.

[Heli Shed]

I'd say partially. With the inclusion of more and more advanced effects(shadows, reflections, HDR, etc.), the strain on the GPU is increasing.

 

Well that, is undeniable I'd agree.

 

Thanks.

 

'T'

[Heli Shed]

Completely incorrect.

 

Multi-threading is multithreading. It is when one process executes in multiple threads. DCS does qualify under this. At no point short of something like Folding@Home or something like your GPU preparing a screenframe would all cores be used for all tasks. It simply doesn't happen.

 

Example from a fairly multithreaded simulator: Rise of Flight. It has graphics in one thread, sound in one, AI in one, phsyics in one. It then distributes these across the available resources, but at any one time any one task will only be taking place in one specific thread and thereby only on one specific core. This does have the effect that you will not typically "max out" almost any CPU with almost any game, multithreaded or not, since by the nature of what they are different natural partitions will place differing demands on execution resources and you'll likely always have one of them bottlenecking your execution for one reason or another.

 

Multithreading computer games is a very difficult proposition that requires careful management of data dependencies, the most common one (indeed the only one I've ever seen) is to segregate distinct parts of a given game engine into separate parts just like RoF does.

 

You kill me Eth.

 

Thats my whole point.

 

Thanks for the 'in-depth' explanation though.

 

'T':thumbup:

[Prophet]

Completely incorrect.

 

Multi-threading is multithreading. It is when one process executes in multiple threads. DCS does qualify under this. At no point short of something like Folding@Home or something like your GPU preparing a screenframe would all cores be used for all tasks. It simply doesn't happen.

 

Example from a fairly multithreaded simulator: Rise of Flight. It has graphics in one thread, sound in one, AI in one, phsyics in one. It then distributes these across the available resources, but at any one time any one task will only be taking place in one specific thread and thereby only on one specific core. This does have the effect that you will not typically "max out" almost any CPU with almost any game, multithreaded or not, since by the nature of what they are different natural partitions will place differing demands on execution resources and you'll likely always have one of them bottlenecking your execution for one reason or another.

 

Multithreading computer games is a very difficult proposition that requires careful management of data dependencies, the most common one (indeed the only one I've ever seen) is to segregate distinct parts of a given game engine into separate parts just like RoF does.

 

When I first heard the sound engine was going to another thread, I naturally figured eventually the physics, weather, AI could be put in to other threads.

 

Considering this game seems so CPU dependent, it would be nice to see anything that would increase performance.

[EtherealN]

Key thing is that the sound engine didn't "go" to another thread.

 

The old sound engine was removed and replaced with a new one, which was prepared for this.