Is dual core support possible?

[vitz3]

First of all I love the emu and the work that you do. If I knew how to code I would totally show up at your house willing to grind out miles of code if you asked. Really man. Great job. [/grovel]

Anyway. The emu runs fine on many PC's nowadays, however, is it possible to add multi-threading support and if so what would the visible benefits be? What would you do with the extra processing power at your disposal?

-Vince

[Ultima]

While I'm no expert, I highly doubt multi-core support would help much, as pSX isn't actually hitting CPU bottlenecks on single-core CPUs (well, unless you take older computers into consideration, in which case the only real solution would just be to upgrade to a faster CPU, dual core or not).

[whitetigerx7]

All single core software works equally as well on dual core CPU using PCs. There is no need for additional code or support. This is a myth many game makers are feeding you which is a line of bullcrap.

[Gamesoul Master]

Yeah, but why would people like the PCSX2 team lie about that kind of stuff...? And I'd assume that the problems people have mentioned here or there would be true also.

But yeah... considering that pSX runs well on any single processor over 1.5 GHz with pretty much flawless performance, I doubt that any dual-core CPU has ever been made that would cause pSX to run at less than peak performance, even if pSX only utilized just one of those cores...

[Ultima]

PCSX2 is horribly bottlenecked by the CPU.

whitetigerx7: I'm sure most people know that dual-core CPUs can run applications made using single-core CPUs just fine, but there's a difference between running fine on a dual-core CPU, and taking advantage of a dual-core CPU. The latter was what vitz3 was referring to, but as has been mentioned, pSX wouldn't need to take advantage of multiple cores, as far as I can see. Of course, that's a simple conjecture coming from someone who doesn't even know the technical details of pSX, so I guess it could be taken with a grain of salt. Even if it could take advantage, I doubt there'd be much of a visible change from our standpoint.

[Haldrie]

I actually have a duel core processor (Intel Core 2 Duo) and pSX runs just as good on it as a single threaded Pentium 4 processor with hardly any processor usage at all even on graphically intensive games. As far as I can tell my video card is doing most of the work.

[Ultima]

Highly doubtful, as pSX only makes use of the graphics card to draw to screen and do the framerate limiting. Other than that, the CPU handles the bulk of the processing. The fact of the matter is, pSX isn't bottlenecked by much other than the CPU, so if your processor is semi-modern (somewhere in the vicinity of 1.5GHz), it'll handle pSX without much issue, and adding cores won't make any difference

[Sune]

MAME has a multithreading switch, which when enabled moves the final blit to its own thread, causing a slight increase in frame rate.

But yeah, pSX already runs fast enough on existing dual core or HT capable CPUs as it is.

[Heihachi_73]

I couldn't help but post, imagine if ZiNc was made the pSX way, without the need for high-res graphics (and accompanying slowdowns). That was my one and only gripe I had with ZiNc, and most likely PCSX2 by the looks of it.

[soltis]

whitetigerx7 said:

All single core software works equally as well on dual core CPU using PCs. There is no need for additional code or support. This is a myth many game makers are feeding you which is a line of bullcrap.

Wrong. Much code that works "okay" on single-core CPUs does NOT work okay on multi-core CPUs due to timing issues, etc. This is most often seen in games (Planetside, Neverwinter Nights, ePSXe, Alpha Centauri, Halo, etc), where running the game on a multi-core processor results in graphical "jumping", sporadic framerate spikes, crashes, etc. Setting the process affinity to just one core solves the problem.

Fortunately, pSX does not have this problem, but that does not mean it doesn't happen.

Of course, I will refrain from making sarcastic comments about what kind of coders must have written those games, for them to work so unreliably.... *Cough* it just means that pSX was written much better than some other programs out there.

[Truth Unknown]

For now, Multi-Threading is not practical for PlayStation Emulation in pSX. In the future, pSX may have PS2 emulation and the use of of Multi-Threading may become needed but this isn't in motion yet.

[whitetigerx7]

Very few applications actually take true advantage of multi-core CPUs and those that do actually don't truly utilize anything but a pre-cashe unit in the CPU. Nothing else. That same pre-cashe is what HyperThreading used on early Pentium 4s. It works better on multi-core CPUs than it did on HyperThreaded ones but in really utilizing that pre-cashe is really not work the trouble.

As far as games like Planetside, Neverwinter Nights, ePSXe, Alpha Centauri, Halo, and others like them go... You may want to recheck the code they used instead of the CPU. Most of those applications ran on bad code or code that was poorly written or written for ealier operating systems.

If anything... the real thing question should have been towards what is the best CPU optimization level. Personally I see nothing using less than a 686 level of CPU with MMX and SSE or 3Dnow! as far as optimizations go and see no reason to use anything less than that level of optimization.

You are looking at a 1.0 GHz optimal CPU utilizing application using basic 686 level CPU optimizations with the graphics offloaded to the DirectDraw and Direct3D API and audio channeled through DirectSound in basic stereo mode with no additional 3D processing.

pSX doesn't need multi-threading support. If anything it needs cleaner code which is already in the works and more optimizations for the current and previous generation of CPUs and video cards. All of which are being taken care of so if pSX doesn't work right the best course of action is to send in bug reports, figure out what settings work best for your system, and ask questions about getting things working more smoothly in certain areas.

[psxchris]

What a funny thread ;D

PSxemu will almost run on an amiga ;D

Well maybe, either way it runs obviously perfect on my AMD X2 AM2 4000+

It runs flawless on my Shuttle P4 2.8 Northwood.

Surprisgly, it runs just fine on my HP laptop with just a P3 933mhz with just 512mb ram.

If you looking for a clear reason for dual core, then play STALKER or some BF2 Special Forces on a 64 player night map!

[Sune]

I am not familiar with any two-player games that used the link cable for the Playstation. Maybe some of the Duke Nukem games?

Anyway, imagine multiple instances of pSX running on separate threads, virtually linked together.

This would be extra cool on a PC with two (or more, if needed) monitors hooked up to it.

[Melanogaster]

Well, I can say that Command & Conquer: Red Alert: Retaliation is one these link cable games... haven't heard (or can't remember now) of any other.