For dummys: how will Unity 5.x affect the performance?

[godefroi]

Given the nature of the Kerbal Mindset, I would say that someone is still going to find a way... 64bit memory addressing just pushes the limits up to insane levels, but doesn't actually get rid of them after all... (Also memory handling isn't 'true' 64bit in most cases, and most systems break down well before their actual 2^64 max. Luckily it is still an insane amount of data before that happens, but, well, 'moar boosters' and whatnot... I expect someone is going to break it sooner or later.)

Correct; Windows <8.1 limited address space to 8TB, or (as it is commonly known) "way more than you could ever hope to physically fit in any computer you could purchase today". Given that the largest DIMM commonly available is 64GB, unless you have a whole lot of memory slots, you're unlikely to be able to install enough for that limit to be a problem.

[CalculusWarrior]

Correct; Windows <8.1 limited address space to 8TB, or (as it is commonly known) "way more than you could ever hope to physically fit in any computer you could purchase today". Given that the largest DIMM commonly available is 64GB, unless you have a whole lot of memory slots, you're unlikely to be able to install enough for that limit to be a problem.

Not to mention there's probably not even enough parts packs to reach 8 TB of RAM usage!

[godefroi]

It starts with all memory access commands of the processor being up to twice as fast than now simply due to the double integer width compared to 32-bit. That alone will improve performance quite a bit, especially loading/saving stuff actions and other stuff that transfers a lot of data to/from the CPU.

The main speed advantage of x64 is that there are more registers available. "Memory access commands" aren't faster, and in some cases, moving a bunch of 64 bit pointers around instead of 32 bit pointers can actually take more time, as well as consume more memory.

It should be a bit faster overall due to the registers, but the x64 compilation alone is likely not going to be a difference you'll notice.

[Kerbart]

Unity 5.x allows the game to run over multiple cores or 64 bit for all platforms which means there is almost no more crashes due to memory limits.

I'll leave it to the pundits to comment on the impact of multiple cores to memory limits.

But... assuming the new Unity gets rid of the 3 GB memory limit imposed by 32 bits, that doesn't mean there are no more crashes due to memory limits.

• Given enough memory hogging mods, you can still run out of memory. Especially if you only have 4GB of RAM
  
• If memory leaks aren't fixed you'll still run out of memory and crash; it will simply take a bit longer (how much longer? depends on how much memory you have)
  
• I'm clueless how windows deals with this, but if this gives KSP the ability to utilize all memory, it might simply be Windows that will do the crashing in that case, instead of KSP

[Luckless]

Not to mention there's probably not even enough parts packs to reach 8 TB of RAM usage!

Yet... But like I said, we're dealing with Kerbal players here, and there IS a mathematical limit involved, so obviously someone is going to try and poke it.

I'll leave it to the pundits to comment on the impact of multiple cores to memory limits.

But... assuming the new Unity gets rid of the 3 GB memory limit imposed by 32 bits, that doesn't mean there are no more crashes due to memory limits.

• Given enough memory hogging mods, you can still run out of memory. Especially if you only have 4GB of RAM
  
• If memory leaks aren't fixed you'll still run out of memory and crash; it will simply take a bit longer (how much longer? depends on how much memory you have)
  
• I'm clueless how windows deals with this, but if this gives KSP the ability to utilize all memory, it might simply be Windows that will do the crashing in that case, instead of KSP

Memory systems of modern operating systems are designed to safely exceed the attached primary memory used as RAM. However, 'fun things' happen when you get into trying to run a program that is forced to page its working storage in and out of primary memory to secondary (hard drive/SSD) storage. You can still reach a limit, and things can still go wrong even if you 'haven't run out of memory', but actual crashes due to that tend to be difficult to pull off.

Edited September 25, 2015 by Luckless

[godefroi]

Memory systems of modern operating systems are designed to safely exceed the attached primary memory used as RAM. However, 'fun things' happen when you get into trying to run a program that is forced to page its working storage in and out of primary memory to secondary (hard drive/SSD) storage. You can still reach a limit, and things can still go wrong even if you 'haven't run out of memory', but actual crashes due to that tend to be difficult to pull off.

And not-so-modern operating systems. Virtual Memory has been available in the x86 line of processors since the 286.

Note that what you run out of is generally address space, not memory. For more information, read these:

http://blogs.msdn.com/b/oldnewthing/archive/2013/06/28/10429807.aspx

http://blogs.msdn.com/b/ericlippert/archive/2009/06/08/out-of-memory-does-not-refer-to-physical-memory.aspx

Raymond Chen and Eric Lippert are extremely smart people; if it can be known about .NET, then Eric knows it. If it can be known about Windows, then Raymond knows it.

Also note that the .NET (and therefore Unity and KSP) "OutOfMemoryException" can happen in all kinds of situations where you were neither out of physical memory nor address space.

[78stonewobble]

Well I might have misunderstood it... but unless there are some news, that I missed. 1.1 (with unity update) won't be 64 bit, but after that, they would look back into the 64 bit version?