Poor performance

[global express]

Actually I think FlightSim does support dual GPU...

For years I was using a default set-up - without altering any Nvidia settings. One day, a friend of mine came round to my house and noticed that my GPUs weren't set in SLI mode! So effectively I was getting 512MB, instead of 1GB! LOL! 

After making this change, there was a huge performance increase in 90% of my sceneries.

I currently have a strange problem with my system though - the lower (2nd) GPU keeps on destroying itself - (I'm on my 4th 9800GT - my system will probably destroy this one too in a week or so, but Dell is offering no other solution - I guess it's over heating?).

Glad my post helped to distinguish a trend in poor performance with Win32XP. Next year I'll be upgrading system.

[Ankh]

Just for your info: if you have 2 GPUs with 512MB VRAM each, you do NOT have 1GB of VRAM. Still, each GPU is capable of accessing only 512MB, meaning that for games with high quality textures, you would still run into the same VRAM limits as with just one GPU. The only advantage of SLI is the fact, that you can split the workload for the GPU on two independent processing units.

[virtuali]

Actually I think FlightSim does support dual GPU...

No, it doesn't. The only possible benefit with a dual-GPU, is that you might not get a large performance *decrease* if you are driving a very large display or if you use advanced antialiasing modes, like 8x FSAA.

For years I was using a default set-up - without altering any Nvidia settings. One day, a friend of mine came round to my house and noticed that my GPUs weren't set in SLI mode! So effectively I was getting 512MB, instead of 1GB! LOL! 

After making this change, there was a huge performance increase in 90% of my sceneries.

That's not what happened. A Dual-gpu with one gpu disabled is NOT the same thing as having a single card. It's possible that with the 2nd GPU disabled, you HAD your 1GB of ram "taken" anyway, but without any benefit that the dual Gpu would give you of driving a large monitor or using antialiasing. So, you didn't really had a performance "increase", you simply restored a normal situation.

I currently have a strange problem with my system though - the lower (2nd) GPU keeps on destroying itself - (I'm on my 4th 9800GT - my system will probably destroy this one too in a week or so, but Dell is offering no other solution - I guess it's over heating?).

It's possible you have an overheating problem, but is strange why it only affects one of the GPUs ? Do you have two physical cards, or a single card with 2 GPUs on it ?

Note that, if there are overheating problems, it's also possible you main CPU is slowing down (that would also explain the low performances) to prevent melting itself (the technology is called Intel SpeedStep)

[virtuali]

Just for your info: if you have 2 GPUs with 512MB VRAM each, you do NOT have 1GB of VRAM.

But you HAVE 1GB of VRAM "taken" anyway if you are running on a 32 bit OS. The mapping into the main 4GB of RAM (since 32 bit OS can't address more than that under ANY case) happens just the same, fact that each of the GPUs can't see more than 512 of it, it's not relevant in this case.

That was precisely my point: using 2 GPU on a 32 bit OS will result in all the disadvantages of having 1GB VRAM with a 32 bit OS, but without any benefit, and particularly with Flight sim, that doesn't really use SLI and, it's not so much graphic-card intensive that using a SLI configuration would get dramatic benefits even if it *did* support it.

[global express]

Do you have two physical cards, or a single card with 2 GPUs on it ?

Yes, I have two separate 9800GT cards. They sit between a 128MB PhysX PCI card - I've no idea what that does. 

Thanks for all the info virtuali. As you can see by my lack of knowledge - I'm not a computer geek!

Looking ahead - what specs are recommended? From reading this post and several hundred others today, I should look for:

Processor - (best you can afford) so for me that'd be an i7 960 / 970, 3.2Hz, 8/12MB cache
OS - Windows 7 64bit?
GC - Single GPU (any reccommendations?) Used ATI previously with no problems, but seem to be stuggling with Nvidia.
Memory - 4GB? FSX apparently can't use more than 4GB?

Thanks for your help
Alex

[virtuali]

Yes, I have two separate 9800GT cards.

In that case, overheating for just one of them doesn't look so strange. Maybe there's bad air circulation inside the case.

Processor - (best you can afford) so for me that'd be an i7 960 / 970, 3.2Hz, 8/12MB cache

Try to get a Sandy Bridge if possible, the 2600 for example is not so expensive. The 960 is already a previous-gen CPU, since it was released 2 years ago.

OS - Windows 7 64bit?

Absolutely, that's what we all at FSDT use now.

GC - Single GPU (any reccommendations?) Used ATI previously with no problems, but seem to be stuggling with Nvidia.

A good one, but without spending too much on it, have a look here:

http://www.tomshardware.com/reviews/fastest-graphics-card-radeon-geforce,3067.html

Both ATI 6870 or nVidia 560 GTX seems to be good choices below 300$

Memory - 4GB? FSX apparently can't use more than 4GB?

Yes, FSX can't use more than 4GB but, what about Windows ? With 4GB in total, FSX *and* Windows will share a total of 4GB, with 6GB or more FSX might at least be able to have 4GB all for itself. I'd say 6GB should be ok.

[JorgeM]

Just try the demo on my XPS studio LAX with the queen getting average fps of 24-25!! its great! love it! thanks guys!
Jorge

[juniormafia27]

I don`t run KLAX on a low end system and there is absolutely no need to answer my question in such a crude note. A simple "no" would have been absolutely sufficient!
I asked, because many users of my forum wanted to know, whether they might encounter performance problems using typical FS9 - machines (eg. E8500). Now I can answer them with a "yes" ...

Anyway the scenery is wonderful if You run it on a high end machine ... great work and absolutely worth buying it.

I agree a simple 'no' would have answered the question.  However my system is now were near "low end" and I get the same issues as well....hell I have the cloud 9 version as well.  But if I had known it would have performed that bad on my set up...I would have never had bought it when I did..... performance wise this airport gets a D+....however looks nice....when not chopped and screwed.

[arntfs]

I suspect the low perfomance issue isnt in any way due to high poly count or low end PCs, but directly linked to poor LOD architecture. And...LOD can be tweaked without re-modelling evreything. We all know that FSX deals LODs in a diffrerent (better) way than fs9.

[virtuali]

I suspect the low perfomance issue isnt in any way due to high poly count or low end PCs, but directly linked to poor LOD architecture

First, there's no "low performance issue" at KLAX, there are only some users with either outdated systems, or new system but badly configured.

See (and read carefully) this message for proof:

http://forum.avsim.net/topic/353381-cloud9-klax/page__view__findpost__p__2160184

Swoop had a very fast system, but his 1GB card under XP 32 bit was the bottleneck, once he upgraded to Win7x64, everything changed, and KLAX started to perform as it was supposed to.

In any case, saying that the problem is not the high-polygon count but the "poor LOD architecture" is self-counterdicting: the LOD IS a way to display less polygons, when the full resolution model has too many of them so, the two are strictly related and, in fact, are the same thing.

And...LOD can be tweaked without re-modelling evreything

No, it can't in this case, which is entirely different.

KLAX for FS9 doesn't have a "poor LOD architecture", it doesn't have ANY LOD at all, for a very simple reason: BECAUSE of the already too high polygonal count, we were so close to the maximum limit that FS9 can handle (32k polygons per drawcall), which is lower than FSX anyway, that putting LOD levels in the objects would result in the FS9 compiler not compiling them anymore, and even by hand-tweaking it to bypass the limit, FS9 wouldn't display the object anyway.

We already *had* the LOD levels, from FSX, but we had to throw away them in FS9 in order to be able to compile the scenery.

Now, before you start jumping "that's it, it's the missing LOD!", the true story, as always, is not so simple.

Modern graphic cards are so fast and with so much *spare* power left when using Flight Sim (and especially FS9), that simply putting a lot of polygons without any LOD could be FASTER than the very act of *switching* between LODs, since there's some computation that affects the CPU involved when deciding which LOD level display based on the object size so, with a fast modern system, this overhead is worse than just drawing *everything* in one go, since the calculations must be made for every object and on every frame.

LOD is very helpful with slower systems, OR systems with less powerful graphic cards OR systems where (like Swoop's) the graphic card was underperforming because of the memory issues in 32 bit.

So, I repeat and confirm: KLAX for FS9 performs normally on a correctly configured fast system. If you have a old PC, there's always the Cloud9 version, which is still on sale and still supported.

[arntfs]

Thanks for the detailed reply Umberto. At any rate, I wont start a debate here.

However, and I am not going to 'start jumping' as you ironically say: I am just taking act that, indeed, the low performance with KLAXv2 is due to inexistant LOD. It is perhaps acceptable because nowadays PC can handle this more or less, but please dont get into the fishy explanations that it IS normal. It is not.

We've all understood well that the FSDT plan was not to port that FSX native scenery to the older platform, we've all noted that we could have used the trial version before purchase (but you seem to ignore that FSDT faithful customer like me always buy blindly your sceneries because we trust the famous quality we expect from your company), that Win7 deals better with memory etc. Etc...But hey, would you have stated that the fs9 scnery did not had LOD, I wouldnt even have downloaded the trial. End of rant. I therefore suggest you warn your future customers about the fact that your LAXv2 fs9 scenery use no LOD at all.

To end with, two things: first, and depsite the performance problems (concerning 'a few of us' as you like to repeat, ok, lets admit that), the scenery is very nice. Second, we can understand that like every FS business around FSDT is suffering from the global economic crisis, and that perhaps explains the selling of a product that isnt optimized for an outdated FS platform.

Best regards.

[virtuali]

I am just taking act that, indeed, the low performance with KLAXv2 is due to inexistant LOD.

No. As I've said, there's no such thing as "low performance" with KLAX2, it's just that it has highest system requirements than the old version, which is fairly obvious considering 5 years have passed since that one, but with a system that CAN handle it, the performances are NOT low, as Swoop's experience can confirm.

It is perhaps acceptable because nowadays PC can handle this more or less, but please dont get into the fishy explanations that it IS normal. It is not.

Modern PCs can handle it very well, not "more or less". As I've already explained, on a fast PC, not using LOD can even be FASTER so, why should we penalize those having modern PCs, with a scenery released at the end of 2011 ?

But hey, would you have stated that the fs9 scnery did not had LOD, I wouldnt even have downloaded the trial. End of rant. I therefore suggest you warn your future customers about the fact that your LAXv2 fs9 scenery use no LOD at all.

This doesn't obviously make any sense, because not having LOD is NOT a problem, and can be even a *feature* for those having a fast PC. Since this is clearly system-dependent, there's nothing better than checking the Trial first.

Second, we can understand that like every FS business around FSDT is suffering from the global economic crisis, and that perhaps explains the selling of a product that isnt optimized for an outdated FS platform.

Another unfunded statement: we are not really suffering from the economic crisis, since our business has always grown through the last years, and we always had good year-to-year increases, your hint that we released a sub-par scenery for FS9 because we were desperate to get more cash, other than being blatantly wrong since the scenery is NOT sub-par and is NOT under-performing on a capable system, is also borderline offensive, and these are exactly the kind of statement that would make us considering (more of ALL cash-related issue) to stop supporting FS9 at once.

And besides, if you have O'Hare, I suggest you to download the FREE UPDATE for it, which works in FS9 too. It took almost a month worth of work, more or less what it took to port KLAX to FS9, but we are giving it away for FREE, and we don't expect O'Hare to sell too many additional copies now, yet we ARE giving it free, because we PROMISED IT.  

So much for your "though economy" theory...

[juniormafia27]

This just keep getting better 

[juniormafia27]

Yes, I have two separate 9800GT cards.

In that case, overheating for just one of them doesn't look so strange. Maybe there's bad air circulation inside the case.

Processor - (best you can afford) so for me that'd be an i7 960 / 970, 3.2Hz, 8/12MB cache

Try to get a Sandy Bridge if possible, the 2600 for example is not so expensive. The 960 is already a previous-gen CPU, since it was released 2 years ago.

OS - Windows 7 64bit?

Absolutely, that's what we all at FSDT use now.

GC - Single GPU (any reccommendations?) Used ATI previously with no problems, but seem to be stuggling with Nvidia.

A good one, but without spending too much on it, have a look here:

http://www.tomshardware.com/reviews/fastest-graphics-card-radeon-geforce,3067.html

Both ATI 6870 or nVidia 560 GTX seems to be good choices below 300$

Memory - 4GB? FSX apparently can't use more than 4GB?

Yes, FSX can't use more than 4GB but, what about Windows ? With 4GB in total, FSX *and* Windows will share a total of 4GB, with 6GB or more FSX might at least be able to have 4GB all for itself. I'd say 6GB should be ok.

So you do suggest Sandy Bridge to be a great processor for FSX with Windows 7 64-bit?

[virtuali]

So you do suggest Sandy Bridge to be a great processor for FSX with Windows 7 64-bit?

Yes, absolutely.