Chris and I wince whenever we see a forum post like this*:
Every time I start up the left engine of the KX-1000 turbojet, rain appears on my right windscreen. I hope 64-bit fixes that!
Seriously though, 64-bit seems to have gained a reputation in the community as the messiah that will cure all evil. This reputation is unfounded.
64-bit will do one and only one thing: allow X-Plane to use significantly more virtual memory without crashing. If you crash because you run out of address space, 64-bit will help you. It is not going to fix anything else.
Here are some things 64-bit will not do:
- 64-bit will not make X-Plane faster. Using more memory doesn’t make things faster. (Nerds: using
IA64x86_64 doesn’t make things faster. We’re not register bound because secretly x86 chips do crazy register renaming. We are, however, L2 bound, and making all of our pointer-based structures 2x in size isn’t a move in the right direction.) Past tests indicate that 64-bit is performance neutral.
- It won’t fix any bugs. If a system is broken in 32-bits, it will be equally broken in 64 bits.
- It won’t make anything look any better. The same settings should produce the same image in 32-bits or 64-bits.
- It won’t bring world peace. For that you need 128 bits.
Actually, that second-to-last statement is slightly not true . With 64 bits, some settings will become possible for some users that were strictly memory bound before. For example, if you couldn’t run extreme texture res and extreme forests only due to memory limits, 64-bits will let you use extreme res and forests, and that probably will look better than having to pick one or the other.
Of course, with the address space limit removed, users will run into a series of new limitations:
- Some users will run out of physical memory. Fortunately RAM is very cheap, but it’s not easy to upgrade in a laptop
or iMac. (I stand corrected: apparently iMac RAM upgrades are now slip-in, which is cool. I think a while ago you had to pop the case, which wasn’t much fun. The TiBooks used to have a RAM drop-in under a pop-off keyboard, which was cool but put constraints on how strong the keyboard could be. But I digress.)
- Some users will not be able to show all of that extra 3-d “stuff” at reasonable framerates.
- Some users will run out of VRAM at the higher texture resolutions.
There’s always one thing that limits performance…64 bit simply ensures that it isn’t the needless artificial limit of a 32-bit process.
* Whenever we see such a post by accident while looking at online shoe catalogs. We do not read the forums! Do not assume that a forum post is a bug report. Insert the rest of the rant here, etc.