For example, did you know that you can get a highly scalable priority queue data structure by just using a skip list and hardware transactional memory? It's so simple that I felt almost ripped off when I realized how much easier TM makes it. If you've ever tried to make a concurrent priority queue with locks or compare-and-swap primitives, you'll be pleasantly surprised by how much easier it could have been if only we had hardware transactional memory.

Is your design pure HTM, or a hybrid approach? Or hardware support for STM? (Which seems more doable). Cliff Click of Azul fame has some interesting comments on how HTM didn't really work as a 'dusty deck' solution for replacing locks, which is why I assumed its support and not a pure HTM implementation.

  What happens if you overflow the 'rollback memory/cache' (or whatever you kids are calling it these days?)

What integer value in a game gets so big that it can potentially overflow a 64 bit integer?

I've literally been thinking about this question for years and I can't think of a single case. Bignums are pretty much only used in scientific computations and the only thing in a game that would come close to this would be encryption, in which case the programmers would know what they are doing and wouldn't mistakenly used fixed size integers.

(Of course back in the day integer overflow bugs in games were everywhere, one awesome example being level number 256 in pacman)

I don't know, why people keep asking for more resources? Maybe he wants to store every pixel, its lightning and physics from a 32 multiplayer game to offer time-machine features (like the TimeShift game). Maybe he wanted to make a scientific game, something like EVE online, but analysing Hubble data. Maybe he just thinks it would be nice to be the first to break the current limits to sell future-proof game engines.

I don't know. But asking why would people ever want more in their computing power than what's been offered has always came back to bite the questioner :)

2^64 meters is only around 1900 lightyears, which is woefully insufficient for a galaxy-scale RTS.

Even 64 bits wouldn't allow for a naive implementation of a realistically scaled space game. There would still have to be a lot of optimization tricks played.

EDIT: I realize that the parents posts are talking about Integers, but you can't send those directly to the GPU!

My favorite integer overflow bug was the max score in original tetris -- 32767. Although seeing IKEA chair* tester's counter overflow and bring the system down is a close second.

[* chair tester just like one shown here: http://www.youtube.com/watch?v=uaZ3ikJ-M4o&NR=1]

What Rob Pike has put into Go, he used in a previous language he developed called Newsqueak, which enabled him to write an entire GUI windowing system in one afternoon. That combination of shared-nothing concurrency and message passing is pretty darned powerful. In such a system, locks are there under the covers and are invisible to the programmer.

I've programmed a lot of both, and while shared nothing makes the easy stuff easier, it doesn't seem to make the hard locking problems any less hard. You still have to think about race conditions and deadlocks.