Just off the top of my head, I'm thinking that there is something that is inherently not thread safe in the sound card driver that gets executed in the Far Cry game. This may be some static variable that is being updated by two different threads or some other, more catastrophic execution sequence is being triggered.
We've seen some ISV's with real-time processing applications recommend the HT be turned off. With HT on, lower priority threads have been seen to get more execution time and throw off the timing of the real-time processing thread.
Another related failure would be time critical computations. For example, if it takes 5 ms to compute a result, it might take8 ms to compute two results with HT. While the results are both available after8 ms andappear to be a 20% increase in speed, if there is a requirement to have the first result at the 5ms mark, the deadline will be missed and the computation wasted or worse.
I've not heard that. Do you have a citation?
I can imagine that it might be possible, but I would think that Microsoft has built in logic to correctly handle HT on their recent OS releases and versions. Hyper-Threading Technology has been available for 2 years or so. If there were any performance problems that were directly linked to HT within Win XP, those should have been corrected by now.