KSP OpenGL RAM magic

[theend3r]

I was overjoyed when I recently tried the -force-opengl option with KSP and found its memory footprint reduced from over 3.7GB (unplayable on 32bit) to stable 1.9GB.

Then it started crashing again so I set out to find the cause and I couldn't believe what I found. The reason was I ran out of RAM completely - I hit the 7GB limit for apps on my 8GB RAM laptop, the sole culprit being KSP.

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How is that possible? How could simply running a 32bit KSP encumber the memory so much? Magic?

[vexx32]

That's one of two possible things. One is that you have a video card built into the motherboard that actually uses some of the system's RAM as video memory.

The other is quite simply one heck of a memory leak, and I'm sure it's not surprising to find that if it's using that much RAM, you're going to have issues. OpenGL is not as stable as it ought to be on all video cards, especially those designed and optimised for use with DirectX.

[biohazard15]

AFAIK, OpenGL does not actually reduce your actual memory footprint - it simply optimizes your memory usage.

To put it simple:

- DirectX loads it all and keeps it all in one process, and since there is a 3.7 Gb cap on 32-bit, it cannot go past that point.

- OpenGL also loads it all, but it uses only what is needed at the moment, allowing stuff that is currently unused reside in the background, ready to be called for. Hence, it allows you to step over 3.7 Gb barrier - until one of two things happen: the actual memory usage caps the barrier, or you run out of RAM.

OpenGL is WAY more optimized than DirectX; sadly, you need a very skilled programmer to use it effectively, and obviously, guys from Unity are not that skilled.

That being said, OpenGL is NOT an option for a weak PCs. On the contrary, you need a good machine with lots of RAM in order to use it up to its potential.

Edited December 13, 2014 by biohazard15

[theend3r]

That's one of two possible things. One is that you have a video card built into the motherboard that actually uses some of the system's RAM as video memory.

The other is quite simply one heck of a memory leak, and I'm sure it's not surprising to find that if it's using that much RAM, you're going to have issues. OpenGL is not as stable as it ought to be on all video cards, especially those designed and optimised for use with DirectX.

I have 1.5GB VRAM GTX660m so I doubt that.

AFAIK, OpenGL does not actually reduce your actual memory footprint - it simply optimizes your memory usage.

To put it simple:

- DirectX loads it all and keeps it all in one process, and since there is a 3.7 Gb cap on 32-bit, it cannot go past that point.

- OpenGL also loads it all, but it uses only what is needed at the moment, allowing stuff that is currently unused reside in the background, ready to be called for. Hence, it allows you to step over 3.7 Gb barrier - until one of two things happen: the actual memory usage caps the barrier, or you run out of RAM.

OpenGL is WAY more optimized than DirectX; sadly, you need a very skilled programmer to use it effectively, and obviously, guys from Unity are not that skilled.

That being said, OpenGL is NOT an option for a weak PCs. On the contrary, you need a good machine with lots of RAM in order to use it up to its potential.

So I need 16GB RAM to play KSP 32bit with mods? Wow.

I think it probably has something to do with the EVE mod as the crashing started happening when it played around with it. I'll look further into it.

[Ippo]

So I need 16GB RAM to play KSP 32bit with mods? Wow.

It wouldn't do you any good, since 32 bit executable cannot index all of it anyway. 3.7GB is the hard cap - period, regardless of how much ram you have.

[theend3r]

It wouldn't do you any good, since 32 bit executable cannot index all of it anyway. 3.7GB is the hard cap - period, regardless of how much ram you have.

Not in this case since it takes up nearly 5GB already. As vexx32 said there's probably some kind of memory leak going on.

[biohazard15]

I have 1.5GB VRAM GTX660m so I doubt that.

So I need 16GB RAM to play KSP 32bit with mods? Wow.

I think it probably has something to do with the EVE mod as the crashing started happening when it played around with it. I'll look further into it.

I have 12 Gb, and I'm not hitting anything; but there are memory leaks, indeed - be it Unity itself, KSP or some mod. Currently, I start at 2.7 Gb, and after several hours of gameplay it approaches 3.5 Gb - I usually restart the game at this point in order to avoid sudden crashes.

[Ruedii]

Try using Linux, the win64 version of KSP is broken, and the problem is upstream in the Unity Engine, so there is nothing Squad can do about it.

If you want 64bit use Linux.