what makes people use 64bit (and how can we avoid it)

[SAI Peregrinus]

o.O I thought 32-bit programming died back in 2006, it's now 2015...

No, 32-bit applications are still quite common. 32-bit OSes are rarer, though most mobile systems are 32-bit.

[Kilmeister]

I have been using 64 Bit Windows KSP since right after 1.0 was released and it has been incredibly stable. The only time It's crashed was due to the memory leak issue that exists in the 32bit build as well (Overheat Bars). Once i learned of that i just hit F10 and viola...No crashes since. There are only a handful of mods that don't work with 64 Bit. The only ones that I actually used were FAR and Realchute. But stock has a little better chute design now, and the new aero is kinda fun in an arcade flyer sort of way. Not enough that it detracts from the game for me like it did Pre 1.0.

My main motivation for switching was to have more mods available to me. I now consider E.V.E a must have (I can't bear looking at a cloudless Kerbin anymore). So that right there almost pushes me to the memory limit. Add on a planet pack and I'm already dealing with CTDs in the 32 bit. So I then had to deal with cherry picking the parts I want and even going and pruning a lot of stock parts that I rarely if ever use. It was always depressing seeing all these wonderful parts that people were creating and knowing that you can't use them without having to sacrifice other things.

Now that I've been using 64 bit, I can just run down the add on release forum or CKAN and see a mod... "NEATO!" Click... and not have to worry about whether or not I have the memory space to use it.

Rough Count by folders: I have 48 Mods installed

[RyanRising]

I don't think we need to avoid it, just make sure the people doing it know what they're doing and know not to report any bugs before reproducing them in 32bit.

[Wjolcz]

AFAIK 64bit is only good for people who like to mod their game a lot? It can use more RAM compared to 32bit. It doesn't increase FPS or graphics, or am I wrong?

[NFUN]

AFAIK 64bit is only good for people who like to mod their game a lot? It can use more RAM compared to 32bit. It doesn't increase FPS or graphics, or am I wrong?

It can allow for mods that enhance graphics...

[SAI Peregrinus]

AFAIK 64bit is only good for people who like to mod their game a lot? It can use more RAM compared to 32bit. It doesn't increase FPS or graphics, or am I wrong?

If it were just 64-bit word size, it would only increase FPS slightly. But modern 64-bit processors also come with SIMD instructions, more registers, etc and can greatly improve the physics performance of the game. Those can't be utilized properly by a 32-bit executable. 64-bit refers not just to the word size but to the entire x86-64 instruction set architecture, and the differences that brings. The x86-64 ISA is inherently faster than the x86 ISA.

Edited June 19, 2015 by SAI Peregrinus

[magnemoe]

There is a very simple answer to this: The devs actually don't know how to do it properly.

If you compare KSP to other Unity games (and all the bugs), it clearly shows that actual coding is not the primary strength of this company.

Still I would imagine texture and model loading an unloading was part of engine and not something who has to be coded, about the same way as windows handles memory. Stuff are loaded on demand and the less used is dropped then memory get low, it stays in memory in case its will be used again.

You own data structures as in the vessel structure you have to handle yourself but that is an just some megabytes.

Have very little experience with unity so don't know.

[Wolf Baginski]

I use 64-bit Windows 7. With only 4GB of RAM that might seem superfluous, but it make a big difference. The 32-bit version grabs a chunk of the 4GB address space for things such as the video RAM.

With only 4GB of RAM I maybe wouldn't see any advantage from a 64-bit version of KSP. I'm using most of my 4GB with 32-bit. With 8GB of RAM, I'd expect things to speed up because there would be far less need for virtual RAM, and a 64-bit KSP would maybe be better able to handle textures and stuff. Though I sometimes wonder why programmers in general insist on keeping everything loaded into RAM, which a disk-cache for the not-in-use stuff might help with.

[Tynrael]

I used x64 pre-beta for a few hundred hours without issue, heard it was broken for 0.90 and stuck with the x32. I noticed a lot of the odd quirks, having occasionally difficulty accessing components or brief input unresponsiveness that I had previously attributed to most likely being part of the 64-bit version were just part of the game itself. I played quite a lot x64 in Linux and had no problems with it, but I encountered some hardware issues with Linux itself that kept requiring an OS re-install every time I would try to fix them. I left Linux not because of how Kerbal performed in it, but because of Linux itself.

I had setup a reasonable group of mods for a 32-bit install of Kerbal but couldn't get it to run, it used about 2.8-3.2GB of RAM after the game had actually begun for the x64 version. It seems Kerbal loads to 99.9% and then has a large spike for RAM usage before lowering again that crashes the game if it peaks too high.

I experience:

60-80FPS with high resolution textures and native AA with x64

or

25-30FPS with medium textures and forced AA on 32-bit (openGL)

That said, I recently had an issue where loading a saved game resulted in a mish-mash of my contract status, funds, science, and available crew members that was a combination of where I had left off and a few hours prior... It made me unhappy and I can't say it is x64 related, I hadn't experienced anything like it ever before, but I'm going to see if I can tolerate the low FPS for a while on 32-bit.

[Red Iron Crown]

Tynrael, how was performance on 32-bit with DirectX? Just trying to get an idea if it's the render method or the bitness of KSP making the difference. I suspect the former but don't really have any data.

[Tynrael]

Tynrael, how was performance on 32-bit with DirectX? Just trying to get an idea if it's the render method or the bitness of KSP making the difference. I suspect the former but don't really have any data.

It is definitely the render method, all x64 really does (for me) is allow the extra memory for more mods and better textures. 32-bit DirectX with just my EVE mods nets me more than 60fps(with large fluctuation into 80+) whereas the openGL gets me a very steady 30ishFPS. x32 openGL uses about 1.7-1.9GB of RAM while DirectX uses 3.2-3.4GB.

It isn't really a fair comparison to say I like x64 because it performs better, because it is x64 with better textures in DirectX vs x32 with lower quality textures and openGL. Apples and oranges.