Overclocked dreamcast

[Saoshyant]

Humm... why does raising the speed corrupts data on a VMU? Maybe the data transfer is clocked at a certain value and if that value fails to happen this is what happens. Speculation of my part, but I guess I answered my own question...

[qatmix]

Dan and I were speakign about this, Is all because the CPU affects several devices (including the modem port (hence no BBA being plugged in just in case).

I am going to test ti throughly later on this week.

[bender]

A bit off-topic. The overclocking mod for the gp32.
http://www.cobbleware.com/gp32/gp32oc.html
This works changing one resistor so you can increase the cpu core voltage. Perhaps there's a way to overclock the sh4 in a similar way, so we'll avoid those problems with the devices

[qatmix]

Im looking at that at the moment. I tried overclockign the DC to 286MHZ but it wouldnt work. Just a black screen. So its back to 240 MHZ until I can find a 44MHZ crystal.

[bender]

I'm thinking that perhaps there's a way to combine both things(changing the crystal for the whole system, maximum that makes everything stable and increasing the cpu core voltage so you can perhaps get some more hertzs).
I've also seen somewhere the cpu voltage mod applied to x86 proccessors. I don't know but perhaps there's also some tolerance with the voltage and the sh4 to gain some hetzs.

[Alexvrb]

The problem with replacing the crystal is that it doesn't control the clock speed of everything. As for vcore increases, you can only feed it so much more before you get nothing in return, and increasing the voltage brings its own set of problems. But if you can find an easy and safe way to do it, it could help it go further. As long as you're being cautious.

[guymelef]

damn it man I need more info about this... someone please write in and tell me what happened!!! it's like watching half of a movie and not the last half

[Mental2k]

it is rather isnt it, i thinki remember following this at the time, did you guys ever get it sorted?

[Alexvrb]

There's no easy way to increase the vcore, heck, there's no remotely sane way to do it period. There's no way that I'm aware of to change the multiplier that is locked at 6. Using a 40mhz crystal will let you overclock to 240Mhz (6 x 40 instead of 6 x 33.3), but I haven't heard anything more on keeping things synchronized. Without sync, the overclock isn't worth as much, because some things benefit even as others suffer.

[soccerboi00]

my parents won't let me do it they never let me do anything fun (j/k)