Open-ps2-loader: [Question] Differences in handling different PS2 revisions...

[J013k]

Recently I made a few tests with some different PS2 revisions.

I tested OPL 1442 & 1562.
I connected my PS2 to a PC with Win 7.

I tested games through USB...
Many FMVs stutters on SCPH-700XX or lower.
While on SCPH-750XX or higher mostly they play fine.

Almost the same issue I had through ETH (SMB).
I could not get intro FMV in Gran Turismo 4 to plays smooth on SCPH-700XX or lower.
While on SCPH-750XX or higher everything was smooth.

[rickgaiser]

I don't think this is a bug.

Newer models have a different IOP (PowerPC + DECKARD emulation). In most cases they are faster than the old models (MIPS R3000).

This makes some drivers, like USB, faster on newer ps2 models.

[J013k]

Out of curiosity if someone wants to view a video about speed and frame-rate differences in FMVs
through ETH between some models, here it is:
https://youtu.be/f38okBiPHVU?t=85.
Unfortunately it has "bizarre" (PL) language, but the data transfer graph should be understandable in all languages.
You can watch the video from 1:25 to 7:50.

In 24 hours AV get out of sync after some time on SCPH-70003.
SCPH-77004 and SCPH-90004 play FMV fine.

In Devil may cry transfer speed for the SCPH-70003 barely hits ~1.3 MB/s making FMV stutter.
SCPH-77004 and SCPH-90004 hit 1.4 MB/s without a problem making FMV smooth.

Intro in Guilty Gear X2 on SCPH-70003 is getting skipped after a few seconds (autor of a video did not push any button).
In SCPH-77004 transfer hits 1.7 MB/s, in SCPH-90004 transfer hits 1.8 MB/s and intro plays without a problem on both consoles.

In Rayman 3 transfer hits ~1.3 MB/s on SCPH-70003.
On SCPH-77004 and SCPH-90004 hit ~1.4 MB/s.
On every console there is stuttering, but mostly it noticeable on SCPH-70003.

In Second Sight transfer hits ~500 KB/s on SCPH-70003, sometimes FMV stutters.
On SCPH-77004 and SCPH-90004 transfer hits ~540 KB/s, FMV plays fine.

[TnA-Plastic]

THX.
Well, this can only be "fixed" by getting the CPU-Load (amount of % of cycles, the SMB-drivers use on the IOP) down.

We are basically using an old calculator, to start a rocket.

The performance of LAN could probably be improved!

[J013k]

Hmm, you give me something to think about...

If old consoles have MIPS R3000, through ETH & SMB performance is noticeable worse.

While the new ones have DECKARD and everything is smooth,
at least for ETH, although through USB many FMVs also play fine..

Do they use the same drivers (of course separate for ETH & USB)?

It is kind of a strange situation that everything is fine from CD\DVD discs, but not through ETH...
If I find some time I can test PS2 NetBox on older consoles through ETH.

[J013k]

I checked Gran Turismo 4 and a few other games with PS2 NetBox*.
This device is communicating with PS2 through ETH. USB ports are only for a power supply.
Every FMVs seems to play fine on all consoles (SCPH-50004\70004\75004),
so maybe there is something wrong with optimization on consoles with MIPS R3000A?

BTW is there a chance to change a label from a bug into a question?

[*] - I know that this project has been abandoned and there is no source code for its modificated OPL version