Dual Core and FSX

[RobbieHe 0]

Now that we know that FSX will be optimized for a dual core CPU, I wonder how it will be implemented. Do you think that the external scenery will be operated by one core and the flight instruments and flight dynamics by the other -- or something like that? How do you guys think this is going to work?RH

[Guest Horst]

http://blogs.msdn.com/sebby1234/archive/20.../06/567438.aspxHorst

[RobbieHe 0]

Thank's, while that info is very general, it will do for now, I guess.RH

[Guest]

The flight sim code (or any application code) can't call the CPU directly. The OS (XP/Vista) does that. What it can do is start lots of threads (or 'mini programs'). This will allow the OS to utilise both the CPU's. This will mainly help performance for DX9 app's (DX10 has a lesser dependence on the CPU).(Edit) Actually if FS were to use multiple processes you could assign them separate CPU's. In that case you could do it.

[Guest tdragger]

The systems are managed by many, many different threads, thread pools, and fibers. It's up to Windows as to which core they execute on.

[RobbieHe 0]

Thanks guys for the info; however, could you water it down a bit for a computer simpleton like myself?To help clarrify this in my mind, I'll ask some questions. As I understand it, dual core CPUs are two CPUs on one chip. To me, that would allow the workload of FSX to be divided into two parts. Right now, FS9 relies on one CPU to do all of the work; if FSX can use two CPUs, then why would we not see twice the performance of a single core CPU running at the same speed?Thanks in advance for your patience,RH

[Guest]

The CPU is not the only bottleneck, even with dual cores theres is the same lag to send data back and forth along the pipeline to the CPU's. And theres alot of other factors too (GPU, memory etc etc)

[RobbieHe 0]

From what I have read, in FS9 anyway, the CPU continues to be the primary factor in predicting performance in terms of frames-per-second. However, given what you said (and holding factors such as GPU, memory, etc. steady), do you think that in a dual core processing machine, the CPU's contribution toward the outcome (measured in frames-per-second) is doubled?RH

[Guest]

Certainly not in FS9. I have a dual core and its like CPU1: 90-100%, CPU2: 10-20% (when running FS only).

[RobbieHe 0]

However, dual core should work in FSX. So, how about the question as it applies to FSX?RH