Not really. It simply wouldn't help the fps in any way. X-Plane 10 primarily uses one resource: Memory bandwidth. THat the resource that really limits X-Plane 10, but not the computing power of the CPU or the GPU. So if it is far from using the computing power of one GPU, what would be the sense to use the computing power of another GPU? It wouldn't be used anyway. Improvements of one component only helps if this resource was a real bottleneck (Amdahl's Law). Add a GPU that runs 15 times faster and a CPU that runs 20 times faster, it wouldn't help if it doesn't improve the memory bandwidth.

A very big VRAM of 4GB and 16 GB RAM can help but most of the other components won't help. IN fact SLI would probably result in lower fps, than the single GPU case.

 

 

I understand that but you missed my point. If you are going to design a sim/game, why would you not design it to utilize the technology available? You can't sit here and tell me a company like EA can make a game (battlefield 3) for instance and obtain 100+ fps on a high end machine and companies like xplane, DCS cannot. What am I missing?

I understand that but you missed my point. If you are going to design a sim/game, why would you not design it to utilize the technology available?

 

You don't develop a new technology without a need. It takes time that can be better spend for necessary features.

At the moment and I would say for the foreseeable future I don't even see what you would want to do with SLI in a flight simulator. When the need arises you can be certain that the technology itself has evolved too.

It would be a pretty stupid move to develop for a technology that you will probably NEVER need!

A flight simulator has very specific needs and there is nothing that you can do against it. You have a huge number of rather simple objects (since they are so far away) So what would you do with a huge amount of computing power to help in this problem? Is this even a feasible answer for your problems or would other methods be more helpful?

When you need a screwdriver even the best hammer can be pretty useless. These technologies are only tools, not magical problem solvers.

You can't sit here and tell me a company like EA can make a game (battlefield 3) for instance and obtain 100+ fps on a high end machine and companies like xplane, DCS cannot. What am I missing?

 

You're missing thats a simulator and a first person shooter are very, very different to run. In a first person shooter, all of the graphics which need to be rendered are in a fairly small area. Anything outside of the small are in which you can travel can have much lower detailed because they exist purely in the distance. Furthermore, there is relatively little to worry about with things such as physics.

 

In a simulator, you need to render not just hundreds of miles in every direction, but many miles up. If you want a hundred miles of rendering in every direction and ten miles up, thats 200x200x10, or 400,000 square miles! Thats a huge undertaking. On top of that, you need to fill it with trees, houses, cars, trucks, AI aircraft, realistic weather patterns, and so on. And just when you thought you were done, you need to take care of all of the aircraft systems, the aircraft rendering, and the flight model.

 

Its much harder to make a great looking sim run with good performance. There is much more to do!

You're missing thats a simulator and a first person shooter are very, very different to run. In a first person shooter, all of the graphics which need to be rendered are in a fairly small area. Anything outside of the small are in which you can travel can have much lower detailed because they exist purely in the distance. Furthermore, there is relatively little to worry about with things such as physics.

 

In a simulator, you need to render not just hundreds of miles in every direction, but many miles up. If you want a hundred miles of rendering in every direction and ten miles up, thats 200x200x10, or 400,000 square miles! Thats a huge undertaking. On top of that, you need to fill it with trees, houses, cars, trucks, AI aircraft, realistic weather patterns, and so on. And just when you thought you were done, you need to take care of all of the aircraft systems, the aircraft rendering, and the flight model.

 

Its much harder to make a great looking sim run with good performance. There is much more to do!

 

All the more reason to incorporate (can't think of a better word) SLI. Why take advantage of multi core CPU'S then. Your arguments hold no weight, and make no sense.

 

SLI could / can only "HELP" with more load on a system, if the software / program were capable of SLI. The day that "MORE" computing power isn't an advantage in the computing world, then I'll accept your argument, until then it makes no sense. More power wherever it is coming from is always a good thing. If multiple graphic GPUS wouldn't be a good idea, then I guess multiple system CPUS isn't an advantage either, think about it.

 

Just because Xplane doesn't take advantage of multiple GPUS (SLI), like FSX (?), doesn't mean it wouldn't be a welcome addition and very advantageous. Single monitor systems are a thing of the past, especially with simulators.

 

Xplane has only been around for 20 years though, wouldn't want to ask for too much, too soon, geez give them time. ^_^

 

Glen

average of about 40-50 fps

 

You don't need more than that, above 25 XP is as smooth as silk, so what's the point of using SLI?

 

 

You don't need more than that, above 25 XP is as smooth as silk, so what's the point of using SLI?

 

 

I can easily tell the difference between 30fps, 60fps, 120fps... For me, anything under 60fps is not fluid.

I can run other non sim titles at 100 fps+ :rolleyes:

 

That's because "non-sim titles" don't push your hardware nearly as hard as a modern flight simulator.

SLI could / can only "HELP" with more load on a system, if the software / program were capable of SLI. The day that "MORE" computing power isn't an advantage in the computing world, then I'll accept your argument, until then it makes no sense. More power wherever it is coming from is always a good thing. If multiple graphic GPUS wouldn't be a good idea, then I guess multiple system CPUS isn't an advantage either, think about it.

 

You completely missed the point. If slowdowns aren't being caused by lack of GPU power then adding more GPU power won't give you better performance. It's like putting a more powerful engine in your car to get better traction when what you really need are new tires.

 

As Longranger said, the bottleneck for X-Plane 10 is memory bandwidth which is mostly a limitation of current hardware. Adding more GPUs won't solve that.

I can easily tell the difference between 30fps, 60fps, 120fps... For me, anything under 60fps is not fluid.

 

I agree with you when playing games like Battlefield 3, yes the difference between 30 and 100 does make a difference, but when it comes to XP you don't need SLI. I got descent processor with a GTX 560 Ti 448 cores and only 4gig of ram and can run XP with high eye-candy and still maintain a minimum of 30 fps which is very smooth.

As usual, I didn't miss anything MM, but you seem to continually miss the point, and again it boggles my mind.

 

Going forward, looking to the future, however you want to put it, SLI would be very beneficial. You can't tell me more GPUS wouldn't be a good thing, don't even try. Simply put, multi large monitor systems ARE becoming the norm. You folks stuck in the past can stay there with your 27" monitors. More and more people are moving to multi large monitor systems where SLI would be very advantageous. Quite living strictly for the now, look to the future, and all the change that needs to take place to make Xplane a viable simulation platform. SLI could only help with regards to the future, please stop negating any positive posts, or progress, that could be made to make Xplane better. I could care less about right now, what can be done to improve for the future, start implementing everything (and the list is huge) that needs to be done to improve Xplane.

 

Glen

 

Carlos, I agree, you don't need sli if your running at such low monitor resolutions, 1920 x 1080, but more and more folks are moving to multi monitor systems where sli would make a huge difference. Just as FSX didn't / doesn't take advantage of it (it actually does to some extent), it's a shame that Xplane doesn't as well. Maybe in the NEAR future.

 

Don't try to tell me people aren't struggling with their performance in Xplane. You can't run with HDR on and any reasonable AA to remove the jaggies, it just can't be done. It becomes even worse with multi monitor systems. Try to turn up any sliders with HDR and good AA and your going to be in the teens with fps in a urban environment. SLI would most definitely help. There is no argument to say it wouldn't. Just because you guys don't want it, or see the need for it, because of "your limited systems" doesn't mean it wouldn't be beneficial to others.

You folks stuck in the past

 

lol...

Glen, Its about choice, not about being stuck in the past. Besides there is nothing that prevents you from using SLI for multimonitor setup today.

Going forward, looking to the future, however you want to put it, SLI would be very beneficial. You can't tell me more GPUS wouldn't be a good thing, don't even try.

Sorry, but you are wrong. You totally miss a crucial problem. Memory bandwidth is one of the core problems of X-Plane 10. SLI doesn't cure this problem instead it would increase the memory traffic significantly.. So how does it solve your problem? In fact it would probably be significantly slower. A problem that is not as uncommon with SLI as some people think. In X-Plane 10 many of the internal shaders of the GPU are in fact in idle mode even when the card is running under full power since its memory frequency is at its maximum.

It is obvious that you do not really understand how different the CPU and GPU cores really are and how they are used and I get the strong feeling that you either didn't read or didn't understand what SLI is and how it really works. It CAN offer advantages but it has to cope with several limitations (as usual).

The best solutions to increase the performance of X-Plane is: increase the amount of (fast) VRAM. Even a slower GPU with 4 GB runs faster than a very fast GPU with 2 GB. Your system RAM shouldn't be out of proportion, so 16 GB are advisable especially if you use OSM maps. And there is an addditional problem: AMD CPUs have obviously more problems to really take advantage of such GPU monsters.

lol...

Glen, Its about choice, not about being stuck in the past. Besides there is nothing that prevents you from using SLI for multimonitor setup today.

 

Glad you saw the humour Carlos. I sometimes think I need to go back to a small single monitor, then I wake up from the bad dream.

 

For someone to say that SLI would not help is just not true. It won't help small single monitor setups, but it will certainly help others. Xplane is not optimized for SLI period, that's a shame, and something that should be looked at moving forward. Why would I spend more money on a second or third GPU if the software is not going to optimally use it, now that doesn't make sense. Optimize for SLI so I can build any system I want and get full value for it, I really hate being limited. FSX does / did enough of that already.

 

Wait a second, Macs can't do SLI period, can they (?), it's becoming clearer now. Lousy machines are always getting in the way of progress.

 

Glen

 

"Memory bandwidth is one of the core problems of X-Plane 10."

 

Then there's another thing that needs to be fixed. As I've always said, I don't want excuses why things can't be done, fix it so it can be done. I have a high(er) end system and still struggle if I try to take advantage of the visual goodies in XPX. It's basically always been my argument against the use of HDR, it's useless with any reasonably high AA setting, and higher visual settings. If SLI won't help this situation then they need to rethink what their doing. Don't design in such a way that is so limiting. I / we want to use large multi monitors, then make sure the software works (is optimized for) with SLI so I can take advantage of that technology, end of argument.

Going forward, looking to the future, however you want to put it, SLI would be very beneficial.

 

Not necessarily.

 

Simply put, multi large monitor systems ARE becoming the norm.

 

Not necessarily.

 

More and more people are moving to multi large monitor systems where SLI would be very advantageous.

 

Not necessarily.

 

 

SLI could only help with regards to the future...

 

Not necessarily.

 

Are you getting it yet? You're making a lot of assumptions.

 

You can't run with HDR on and any reasonable AA to remove the jaggies, it just can't be done. It becomes even worse with multi monitor systems.

 

Again, it's a memory bandwidth issue. Flight simulators are about moving huge chunks of data around. You can have a blazing fast CPU/GPU, but if the pipe between them is too narrow then a lot of that power is spent idling while waiting for the data to catch up.

 

And this isn't something that can simply be "fixed" in software. It's like having the most efficient water pump in the world being fed by a narrow pipe. You can tune the performance of the pump all you want, but it's not going to work any faster until you feed it with a bigger pipe.

 

In other words, we're waiting for our hardware to catch up with our software.

"In other words, we're waiting for our hardware to catch up with our software."

 

Really?

 

SLI is, and always has been a hardware advancement in technology (for years), and it does work very well, WHEN the software is optimized to take advantage of it. No need to catch up, the hardware already has as far as Gpu's go, it's called SLI. The only thing that needs to catch up is Xplane, and take advantage of SLI. Blame it on memory bandwith, blame it on whatever you like, SLI would be advantageous to Xplane, period.

 

Are YOU getting it?

 

Glen

 

Just to add, it doesn't need to be SLI, a multi core Gpu will do just fine. Xplane will still be the limiting factor, not the hardware.

 

Years ago, the excuses for poor performing programs was they were only 8 bit. Then we had 16, 32, and now we have 64 bit systems. Xplane is now 64 bit, are we still going to use the same old excuses? What do we have to wait for 128 bit, you'll still use the same old excuse. The hardware is available today, use it in an optimized fashion.