Overclocking the EE (discussion) (testers wanted)

[dabore]

Well, I want the feature in a basic form (but easy to implement).
Our cycle counting isn't exact enough and we haven't found an idea yet on how to make it better.
(The problems are superscalar EE and unknown at recompile time memory latencies.)
By adding the overclock feature, I can better test and debug cycle counting.
I'm just not sure it should be exposed to regular users now. The feature can very easily lead
to misconfiguration when people try to "optimize" everything (and that's what we regularly see).

i agree to leaving that overclock out of the UI. i dunno how this scalar stuff is used anyway. i guess i have to stick my nose in the machine again and follow it. but the point is if it's generally overclocking like some 700Mhz EE it's seriously raising the need to emulate the speed. it might speed up the games run slow on the hardware. but on "faster" games it might spend useless time - however - even if it might spend "empty" cycles on sync points. but i have no clue how "empty" would be done. cause i haven't the sync points in my head. the obvious last instance is running at 60fps. ofc.

[babble]
timing and sync is seriously confusing sometimes. i mean target is to run all as fast as possible til you flip the frame and hopefully have everything rendered in that 16ms to get the stable 60fps on monitor absolute. i know SOC doesn't do that. but i can't picture the timing relation between real ps2 fps on that offset V/S with that "wrong emulated speed" fps on V/S on pc monitor. so... yeah... i gotta seriously look in the machine. and pcsx2 has gotten like a lil closed box with just a couple holes to me. this' me so bad not actively coding tho. i'll look it up.
[/babble]

[dogen]

it might speed up the games run slow on the hardware. but on "faster" games it might spend useless time - however - even if it might spend "empty" cycles on sync points.

Doesn't the wait loop hack help with this?

[dabore]

yeh... okay. maybe. i'm not sure if it's a generally hack that works in every game. if it would be that one could do some general all overclocking. maybe automatic "oc" (or a general 60 fps hack) to raise slow fames to 60 fps. the 60 fps could be counted on frame/field flip rendering the crt. last instance. this might work. i dunno how the timing chain would run down tho to EE to balance and how the oc works with the VU speed which is another heavy "sync wait"- factor. so... yeah... per simple logic... it's demanding the hardware right there naturally... ofc.

[rama]

The "scalar stuff" is used to weight blocks of recompiled code. Smaller blocks tend to require tighter timings than large blocks.
It's all just a crude estimate anyway though, depending on what a game does the virtual EE might run from "150Mhz" to "600Mhz" with the average
game doing pretty much 300Mhz. On average

VU cycle stealing means after the VU are done for their current block, the code increases the EE cycle counter by some amount.
Those cycles are then "stolen" and the EE can do less work in that period because it runs out faster. (Timing code is pretty complex.)
Because the VU have only a hint of timing anyway, it doesn't make sense to bodge that any further with more settings.

[Blyss Sarania]

Okay, I got the change ported over to the latest source. I will send out PMs momentarily.

Meanwhile I made a fork of PCSX2 with the change, you can see the changes here: Sarania/PCSX2/EE slider overclock if you are interested.

If you are going to test the OC build, you absolutely must read this:

I couldn't get wxslider to go from -2 to +2 like I wanted(which would have kept it "lined up" with the current slider). What that means is any time you switch between the OC build and the normal build YOU MUST RESET THE EE SLIDER MANUALLY, ELSE IT WON'T BE WHERE YOU EXPECT. [/size]

I am including this disclaimer in all PMs too.

[Serial Hacker]

any news on GS overclocking

[Blyss Sarania]

Alright, I sent out the builds. If I missed anyone, sorry! Let me know

I agree with rama also - People trying to "optimize" things when they have no idea what they are doing is already a problem, and this could definitely be abused that way. That is exactly why I didn't even bring it up before now, and why I only sent out builds in PM.

[Blyss Sarania]

Well, rama figured out how to make the slider line up with the current one so that INI issue won't be an issue anymore. It still applies to the builds I sent out, but since they are only tester versions and since you guys all got notified it's no problem.

[dabore]

@rama - i get that vu steal!? it's making the EE think it did that "additive" of cycles already?!? relatively clocking down. or raising the VU exec per "EE cycle". tho...

combining EE 2 with VU 2 is counting a lil weird then. but it's the work balance of the games i guess. sorta bottleneck. do i wanna how dmc's huge speedup relates with that mechanic and the mtvu?!? j/k

[dogen]

Alright, I sent out the builds. If I missed anyone, sorry! Let me know

I agree with rama also - People trying to "optimize" things when they have no idea what they are doing is already a problem, and this could definitely be abused that way. That is exactly why I didn't even bring it up before now, and why I only sent out builds in PM.

Can I get one? I have a good amount of games I can test it with.