Daisuke72 said:
DarkTemplar said:
I believe that one of the biggest challenges of PS4/X1 is the efficient use of the 8 cores on their CPU.
The single thread performance of Jaguar cores are not that good (which is expected since one of its targets are Tablets and Netbooks). It also does not have something like Intel's Turbo Bust to improve its single thread performance by a dynamic/on-demand overclock. To offset these limitations, developers have the option to parallelize their CPU intensive code.
Unfortunately to create such a code developers have to face some interesting problems:
1) Not every task can be parallelized;
2) Some task can be parallelized but the result is a code that runs slower than the original code;
3) Once parallelized a code becomes non-deterministic which may lead to a lot of trouble to test it;
4) Data synchronization (starvation, racing conditions, deadlock, etc.);
5) Using 100% of 8 cores at the same time is almost impossible unless you are coding a solution to something homogeneous like weather forecast;
By the way, I read that since their CPU is essentially two independent Jaguar combined hence the CPU may not be suited to allow a process to have access to the 8 cores at the same time (four cores for each process), can someone please confirm this to me? |
Most of the problems you listed developers had to face this generation with the Cell and it's SPU's, except that it'll be much simpler to code for due to the architecture and you don't need to write custom code like you had to do with the cell, and yeah I also heard they were basically glued together, but I doubt any process would need more than four cores.
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Modern games are not CPU demanding. For instance, if you have a code that has a lot of float point operations and it is running on the CPU you probably are wasting resources since the GPU is much more suited to perform this type of operation (consequently the game becomes even less CPU demanding).
This is why also think that 4 Jaguar cores and even 3 PPC 750 cores maybe more than enough to the next gen games (btw notice that the Wii U CPU was made for lazy developers since one of its cores has more cache, enabling single thread code to run quite well on it).
And finally, since Sony and MS decided to use only half of the CPU (4 cores) for games this maybe a hint to an OS with lots things running on the background (perhaps they are working on even more features for the SO than what we know so far).
