Is it possible to read from two USB ports at the same time?

[perfect_genius]

I'm new to PS2 development and have read a lot of information but haven't found anything about reading from two USB sticks at the same time. In theory, this would double the reading speed.
Also, the ps2sdk repository is hard to understand on the topic of USB.

 

[akuhak]

USB is limited to the USB1.1 specs and does not rely on usb port used. In theory if you will to y to read from 2 usb simultaneously you will get half max speed on both.

 

[perfect_genius]

you will get half max speed on both.

But why? Because the IOP will have to constantly switch between ports?
But what about the ability of MIPS to execute several instructions in parallel?

 

[Coro]

it is just the nature of USB. AFAIK most devices with 2 ports actually have 1 port with 2 slots (a sort of built-in mini hub). if there were 2 true ports, there would be no slow down.

 

[perfect_genius]

It turns out that research is needed here.
I wrote a program to read a file from two USBs, and yes - the speed dropped by half. One person suggested that I run a read on two threads, but PS2 threads are cooperative, not parallel, right?
As a result, now I will go to low-level access, the USB driver.

 

[60fpshacksrock]

I have thought about this too. If the VMC were on a separate USB drive it could, for some games, write faster. The reason being because some games have to read data and write to VMC at the nearly the same time causes both read and write to slow down.

Burnout 3 is one such game that takes way too long to save to VMC on USB.

 

[perfect_genius]

There is very little about USB in this analysis: psi-rockin.github.io/ps2tek/
IOP Interrupts: 22 IRQ22 USB
IOP DMA: 24-27 Channel 'U' (USB DMA, controlled through USB registers)
Does anyone know what these registers are? How does USB work at a low level?

 

[TnA]

I suggest to ask on the PS2-Scene-Discord as well, if you didn't yet.

 

[perfect_genius]

I just asked the author of DobieStation, he knows little about USB.

 

[SKEPTiCK]

In theory, this would double the reading speed.

Ok, I have already had this argument with 3 different people in a short amount of time... Maybe you are not those same people in particular but I am going to go right along with the mental agony I've already been presented.

If a PS3 is going to divide read and transfer speeds when you are pulling from multiple USBs at once, what makes you think the console 6 years older (PS2) is going to be capable of the sorcery that you are demanding???

Why is the sky blue? Why is the grass green? Why sometimes when you fart does it stink and other times it doesn't?

So many questions devoid of a single morsel of a common thought... Even if the speeds between read and write could be enhanced, it would probably be such a minuscule difference that you'd hardly even notice on what is comparatively considered as ancient tech nowadays. Every PlayStation beyond the 2 is better to ask in which to perform the function that you're asking for than the PS2.

Idk, maybe go get a PS2 HDD so you could play games from there instead... To read & write for what exactly? Maybe I'm the one whose brain cells are fried but dammit at least the sorry machine is capable of anything at all, hmm...

 

[TnA]

It's possible for USB+MX4SIO, but not on USB+USB with our current software and IDK if it is technically possible. It seems it has a shared bus, so no...