Hyrule Field Slowdown Observation

[NaturalViolence]

Quote:
The major pisser with emulation especially emulation of more powerful consoles, is the actual hardware has a high bandwidth bus between the memory, cpu and gpu whilst PC hardware is lacking in that aspect. That's one reason why full speed emulation isn't possible without hacks. If PC hardware was powerful enough things like Copy EFB to Ram, DSP-LLE would could be used without any slowdowns. I wonder if future PC hardware would be enough to run the interpreter core at full speed.

How do you figure that? Xbox360 and ps3 currently have the highest video memory bandwidth, both at about 25GB/s. Most gaming PCs have at least 4 times that much now and days. Don't even get me started on system ram, most gaming PCs have ddr3 ram with several times the memory bandwidth of the 360, the xdr ram of the ps3 I will admit has higher bandwidth than anything you can achieve with ddr3. And of course cpu/gpu communication is done through the pci-e bus on a pc, which is far faster than we even need. No out of the three "next gen" consoles the PS3 is the only one with better bandwidth than a typical modern gaming pc and even then only cpu/gpu and cpu/mem, pc still kicks it's ass in gpu/vdram. Besides if that were true then memory bandwidth, video memory bandwidth, and NB bandwidth would have an effect on the speed of dolphin with lle and copy efb to ram, and it doesn't. Me and JADS have been benchmarking the last couple of weeks and memory bandwidth doesn't seem to be having any effect on dolphin with ANY settings. The two biggest variables that impact the speed of dolphin's emulation are gpu fill rates and cpu core clock rate. Some other variables such as sse version have a small impact but nothing compared to those two. Dolphin is slow for the simple reason that everything has to be emulated, all the bandwidth in the world won't save you from that.

[skid]

Yeh, "bandwidth bus" was a poor choice of words by Xtreme2damax. His idea is basically correct, as is yours, NaturalViolence.

It's looking to me like this Hyrule Field problem is caused by Dolphin being just plain slow. Maybe synchronizing the threads a bit smarter or rethinking the timing system can speed the emulator up, but these are drastic changes.

Other suggestions to speed up the emulator include caching the vertices (has been suggested by more than one person) and a greater use of OpenCL to cache textures. Currently, it's all talk and no code.

[Xtreme2damax]

I'm trying to tinker with Fifo_EnterLoop but I basically suck at this and I'm not even sure if that is the problem. I'm not sure why this is the most intensive.

The problem just seems weird that it's not triggered until a certain point of the game, immediately after visiting Hyrule Field North and then even slower after Goron Mines despite no changes in the geometry being rendered.

I'm at a loss of words now and I keep beating myself up trying to mess with things.

[deathjijn]

Actualy doesnt the game place difrrent monster at that point and also changes to the sky. Slowdown doesnt seem to occur till the Bulblins ride into to town if you understand what im saying. I think we may be looking in the wrong direction. The area itself geotmetry wise doesn't change but the outlaying monsters do like the Bulblin on pigs. not to mention another varation of a monster doesnt accur till that time frame like the Bokoblin. theres small changes that no one has even thought of that occurs at that point its mostly monsters and the change in texuture to other monsters that occur during this time. And yes i did do my research on this before i posted this im sure if you looks further into it theres your fix.

[ZEROx]

Just a little info for compilers:
Everybody knows that ZTP slower on latest revs than on 50xx for example, if you want to play on newest builds and keep the speed just downgrade
Core\Core\Src\PowerPc\Jit64\Jit_Integer.cpp to 5370 and than compile

[Maragnus]

I stepped through both GL and D3D plugins to check rendering states and settings, everything looks peachy to me so it doesn't appear to be an obvious and simple bug.

On the note of rendering different creatures... Does anyone notice that during the intro, the beginning runs great but once you see the wolf form and the shadow veil, the frame rate notably drops? Maybe it is a specific shader or something about rendering the shadow world. I would bet that this slowdown is related.

I wish there was a way to monitor the time taken by the various parts of the JIT and GPU per frame, that could show us exactly what parts of dolphin or its plugins are struggling with those areas.

[jakeslogan]

any1 here know TLoZelda Oot? Emulator on PC show that it has a cheat that allows Link to levitate, with that cheat u can go to many inaccessible place(access only until certain things have done).
How bout adding in the cheat list of Twilight Princess that kind of cheatcode? with this cheat, We may be able to gain access to the North Hyrule field in the begining and see if the slowdown actually happens???

[shortzi]

(05-03-2010, 11:25 PM)jakeslogan Wrote: any1 here know TLoZelda Oot? Emulator on PC show that it has a cheat that allows Link to levitate, with that cheat u can go to many inaccessible place(access only until certain things have done).
How bout adding in the cheat list of Twilight Princess that kind of cheatcode? with this cheat, We may be able to gain access to the North Hyrule field in the begining and see if the slowdown actually happens???

I was just about to post that, i have the full area map open without doing anything in the game, One quick run-a-round, From East-Noth-West-South, and it still slows down.

As soon as you hit Hyrule Field north frames drop 5fps, then as every other map is open frames continue to drop untill around 12fps.

Even if after i done that, enter back into the woods, then return to the field the slowdown is still present.

I can attach a save file if anyone wants to play with it.

*EDIT* Gamesave and Game config attached.
Save is PAL NGC version.
GameConfig has cheats moonjump etc activated.

[jakeslogan]

Sure, please post it, i wanna try it out. ^^

#Edit: Thanks shortzi, but im running a different version of the game(not PAL) so i can't use your save file. if u don't mind, could you tell me what you did to gain access to any area without doing anything???

[Xtreme2damax]

I wonder if there is a way to make the fifo/gpu not consume a full core, or at least make the Fifo_EnterLoop function less intensive. There's got to be a way to relax this function while other tasks are being performed.

I tried adding Sleep(1); after the following in the Fifo_EnterLoop function but it didn't do much good:

VideoFifo_CheckEFBAccess();
VideoFifo_CheckSwapRequest();

Also, reverting Core\Core\Src\PowerPc\Jit64\Jit_Integer.cpp gave me a bit more speed in Hyrule Field as ZEROx mentioned.