Psx4gp2x Beta Testers Thread

[ruffnutts]

Please someone try

wild arms
kula world
brave fencer
Dark forces
Exhumed

thease are what i tested on the old version

cheers

 

[nubie]

@ZodTTD

Are you planning a Hardcore Homebrew release of the emulator?

Reesy is going to try and move DrMD over to HH and get a big speed boost once they get sound working.

You could start moving over now because the sound is such a huge slow-down anyway and Linux is getting in the way of proper hardware use right now.

@Paradox and Paulo Becker

The First Edition has 3 thermal pads, they seem to be insulators, if anything that would make it hotter.

I don't know what kind of thermal pad you guys are talking about, I have never heard of anything that wasn't metal used to successfully convect heat away from a processor.

Also, reliable sources have mentioned that the ARM processors are not really heat-prone.

If you want to see that, open the GP2X, remove the "Thermal" insulators making it hotter, and then do the overclock and play some PSX and see how hot it really is getting.

There is room for a real piece of metal to use as a heatsink, I do not know if it is necessary however.

 

[Fishbong]

Well a heatsink would be a good idea if the CPU would actually get hot.

Which it does not.

And the effect of the temperature on the overclocking capability of RISC processors is laughable anyway, as long as it doesn´t exceed about 50°C. And as long as you don´t cool it to the point of superconductivity, you won´t get a decent increase in clockspeeds.

The only way to do that is increasing the core voltage of the CPU.

 

[EvilDragon]

The First Edition has 3 thermal pads, they seem to be insulators, if anything that would make it hotter.

I don't know what kind of thermal pad you guys are talking about, I have never heard of anything that wasn't metal used to successfully convect heat away from a processor.

These are no thermal pads. They are simply some rubber pads which push from the back towards the LCD so that it stays in-place. However, this also caused the annoying plasma-effect in the middle of the screen when you press the stick button.
The later units have the LCD glued to the top, so that these pads are no longer needed.

 

[Paradox]

the thermal pads dissipate the heat onto the back on the lcd, thats how im able to overclock more with them

 

[Vimacs]

but isnt heat pretty bad for tft's?

 

[Jarska333]

And as long as you don´t cool it to the point of superconductivity, you won´t get a decent increase in clockspeeds.

Tell me more. B) B) B) Would liquid nitrogen suffice? :unsure: :unsure: :unsure:

 

[reallynotnick]

Wasn't beta 2 supposed to be out awhile ago or do I have my dates mixed up?

EDIT: By no means did I want it rushed, I just recall him announcing it coming out on a set date and then nothing. Just wanting to know what happened.

 

[Vimacs]

its done when its done...

 

[daclassicgamingmaster]

its done when its done...

That's not an answer vimacs

When will the public release of beta 1 be? I know I for one am looking foward to trying it out.

 

[PokeParadox]

ZodTTD did say he was planning to release beta 2 shortly after beta 1. This has obviously changed. Hopefully this just means when we do see another release it will be even funkier.

 

[Epicenter]

the thermal pads dissipate the heat onto the back on the lcd, thats how im able to overclock more with them

This is exceedingly improbable. An ARM920T utilizes, and therefore can dissipate, 0.25mW of heat per MHz with cache utilization. At 200 MHz, that is 50mW, or 50 thousandths of 1 watt. Imagine a 60-watt light bulb's heat output, and imagine that compared to 50 thousandths of 1 watt. See a heat problem? Neither do I. Now, jack the CPU up to 300 MHz. 300*0.25mW = 75mW, still just 75 thousandths of 1 watt. Negligable, with the ARM940T doing about nothing and most of the other components likely emitting exceedingly little heat. The hottest component is probably the video scaler in the MMSP2, since it seems to consume far more power than anything else.

Long story short, processors do not benefit in stability from tiny temperature deltas, esp. when they were nowhere near leaving spec to begin with. Maybe if you took the ARM920T core temperature way below 0C you'd see some improvement in stability. Besides that, I think you're just percieving it.

 

[paulobecker]

So if it's not temperature, what causes instability when overclocking? The only problem I know that derives from overclocking is when tiny components of the microprocessor overheat, then expand and touch each other, causing unexpected changes to the circuitry layout. But if that's not what causes the GP2X to crash, what does?

 

[Paradox]

the thermal pads dissipate the heat onto the back on the lcd, thats how im able to overclock more with them

This is exceedingly improbable. An ARM920T utilizes, and therefore can dissipate, 0.25mW of heat per MHz with cache utilization. At 200 MHz, that is 50mW, or 50 thousandths of 1 watt. Imagine a 60-watt light bulb's heat output, and imagine that compared to 50 thousandths of 1 watt. See a heat problem? Neither do I. Now, jack the CPU up to 300 MHz. 300*0.25mW = 75mW, still just 75 thousandths of 1 watt. Negligable, with the ARM940T doing about nothing and most of the other components likely emitting exceedingly little heat. The hottest component is probably the video scaler in the MMSP2, since it seems to consume far more power than anything else.

Long story short, processors do not benefit in stability from tiny temperature deltas, esp. when they were nowhere near leaving spec to begin with. Maybe if you took the ARM920T core temperature way below 0C you'd see some improvement in stability. Besides that, I think you're just percieving it.

you dont have to argue with me, everyone on IRC told me that thats how it works. but how else can you explain why putting thermal pads on my cpu's allows me to overclock more?

 

[EvilDragon]

Well, if you mean the pads that are included within the First Edition:
Those are on the MMSP2-Chip, NOT on the ARM CPU.

Regarding the Overclocking / Temperature thing:
It's true that x86 CPUs crash because thy get too hot when overclocking.
However, ARMs don't. They crash when the voltage is too high, this is why the pencil trick works to overclock the GP32 more (higher resistor = lower voltage for the processor).

If you can overclock your gp2x higher because you have cooling pads installed, it might be because they also change the resistor a bit... but the cooling is not the reason for your overclocking possibility.

 

[Vimacs]

uhm, sorry EvilDragon, but your post seems wrong to me.
the cpu is inside the mmsp2, and it crashes couse the signal levels get to weak higher voltage can help stabilize them thats why you add graphite at the gp32 it lowers the resistance and so increases the voltage.

 

[CABBAGES]

higher resistence means higher voltage V=IR V-voltage I-amps R=resistance. I think using the pencil thingy would add resistance.

anyway wheres the rest of the videos ?

 

[Vimacs]

now im confused

 

[Jarska333]

higher resistence means higher voltage V=IR V-voltage I-amps R=resistance. I think using the pencil thingy would add resistance.

Nah, the graphite in pencil is conductive, I should think.

 

[Emu&Co]

It's not interesting why it works. It works and it should be possible on GP2X, too.