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Would quad-core support be useless?
#21
(05-25-2009, 11:41 PM)Air Wrote: Overkill.

There are basically four truly viable threads in Pcsx2's core emulation (GS software rasterizer excluded): EmotionEngine, VU1, VU0, and GS core. The IOP may also be threaded, but I'm not sure yet if it'll be much of a performance gainer. If so that'd max it out at five.

However some of those threads are still synchronized with the actions of others. For example the EE core is still the director of the orchestra, and if the EE's tied up with some hard work it can't tell the VUs and GS their next tasks. During such time those threads will idle. And most games don't use the VU0 as a parallel processor much at all, so it'd only be like a little sliver of CPU time. But what having an i7 will do for you is improve task switching and thread sync overhead, so that the 3-5 active threads will still be able to "play nicer" than they would on a cpu with fewer threads/cores. So the emu would still benefit in a small way (very small).

From a brief discussion with cotton, he had mentioned that splitting out the IOP and IPU might also be worthwhile, while keeping VU0 in with the EE (as you mentioned). Is that a possibility?

@Chris, I'm not pretending, I'm just not motivated to help someone with your attitude.

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#22
Splitting the IPU's probably pointless, performance wise. It works in such small data chunks that it's not going to see any real speed benefits from being threaded. It's also something that would need to be recoded to be threaded. The current system uses "coroutine" logic, which is basically a built-in hard coded task switcher. Very evil and impossible to debug, and for that reason alone I'd rather see a threaded version implemented. But would it be faster? Doubtful.

Most games use the VU0 chip through the EE's COP2 unit, which executes 1 instruction at a time (basically works just like the x86 FPU in that mode). In said mode it will always be single-threaded with the EE since the COP2 instructions are literally compiled inline with the EE's recompiled instructions. It would only go threaded if it invokes the VU0's parallel "micro mode" execution. There's really no reason not to thread micro mode, when it's used (which is rarely).
Jake Stine (Air) - Programmer - PCSX2 Dev Team
#23
Thank you, Air! Not only was your response helpful and enlightening; it was also entertaining. Keep up the good work. PCSX2 means more to me than I could ever let you know and I'm sure there are dozens of thousands of others just like me.

@Prodigion: I didn't want your help. I told you to stop responding. Only someone that knows a lot about PCSX2 would be able to help me. That is not you. That's not an insult or a bad thing though. Only a PCSX2 coder could give me the information I need.
#24
(05-26-2009, 12:13 AM)Chris8282 Wrote: Thank you, Air! Not only was your response helpful and enlightening; it was also entertaining. Keep up the good work. PCSX2 means more to me than I could ever let you know and I'm sure there are dozens of thousands of others just like me.

@Prodigion: I didn't want your help. I told you to stop responding. Only someone that knows a lot about PCSX2 would be able to help me. That is not you. That's not an insult or a bad thing though. Only a PCSX2 coder could give me the information I need.

Maybe, but you asked a simple question, and I gave a simple answer (which I had discussed with the devs before).

As a more general question, you've been asking a lot about new features (Anisotropic filtering, multi-threaded support, etc.). Are you planning on helping them develop?
#25
I didn't ask for any of those features. Do you even bother to read? In each of those topics I asked a question ("Are there any plans for Anisotropic filtering?" "Would quad-core support be useful?"). I've never once asked for a feature.

I suggest you take your brain off standby and start reading.
#26
There's irony in the fact you've not been warned for flaming..

And, there would be 50% extra available power, I never said it'd get used, nor did I say I knew about coding etc etc.. Nor did I say that two cores were being used 100%...
AMD Phenom II 940 @ 3.6GHZ, 4GB PC8500 @ 1100MHZ, 4870x2 @ Stock.
#27
(05-26-2009, 12:43 AM)Chris8282 Wrote: I didn't ask for any of those features. Do you even bother to read? In each of those topics I asked a question ("Are there any plans for Anisotropic filtering?" "Would quad-core support be useful?"). I've never once asked for a feature.

I suggest you take your brain off standby and start reading.

Ummm..."asking about new features" does not equal "asking for new features".

How about you stop flaming... and answer the question?
#28
No. Asking if certain features are going to be implemented is not the same as asking for a new feature. If the developers don't plan to implement a feature then I'm not going to push them. They know what they're doing.
#29
Hey we cant all be Computer Science Majors after all, we no smart :C
#30
(05-26-2009, 12:47 AM)Sythedragon Wrote: There's irony in the fact you've not been warned for flaming..

That's not irony. It might be 'odd' or 'interesting' or perhaps even 'amazing' .. but not irony (an oft-misused word). Irony is when something like that is said by someone who is also constantly walking the tight-rope of being warned himself, and as such it's equally amazing he hasn't received one either. So there is some brilliant irony in your post, just not the sort you planned for.

Actually, the only reason I haven't issued warnings is because this whole thread is a running catastrophe of perpetual idiocy from all sides, and if I warn one person I have to in fairness warn nearly everyone who's posted here .. and I'm just too nice for that. To recap: The first couple replies totally missed the purpose of the original post, and insults from all angles ensued. And here we still have it continuing:

Prodigion Wrote:As a more general question, you've been asking a lot about new features (Anisotropic filtering, multi-threaded support, etc.). Are you planning on helping them develop?

CHRIS DID NOT ASK FOR QUAD CORE SUPPORT. Seriously, go back and read the original post. His suggestion was that the devs should place a disclaimer in the FAQ, ala Dolphin's, that expressly denounces quad core as a viable performance enhancer (if, in fact, Pcsx2 were like Dolphin and unable to benefit from additional multithreadedness). He did not -- NOT -- ask for quad core support. No less than 7 posts in this thread totally missed that fact, and/or continued to refuse to stand corrected when the OP pointed out the lack of comprehension. If I were the OP and I were reading these replies, I'd be pretty frustrated too, honestly.

Closed: Original questions answered, and any other Quad Core debates are a beaten horse.

And for future reference: If you absolutely know that you want to speak to Devs and devs alone, close your thread after posting, or use the PM system. It's a lot easier and a lot less likely to start flame wars than telling everyone else to get off your thread's lawn.
Jake Stine (Air) - Programmer - PCSX2 Dev Team




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