What all do u need to Overclock your DC?

[royhubbs]

thats it^^^ ive read a tutorial, doesent seem to hard, but what do i overclock it with?

[dcmodder]

uh a wire and a dreamcast. you dont actually need an oscilator to do it. just remember that you can completely screw up your dreamcast by doing this. i already lost one to it and i (along with others) consider myself to be a pretty careful modder.

[HomerCIDAL]

If you are hoping for it to run your games better, it will probably be a waste of time. The overclocking is best for the development side of things where people make demos and things like that. There is no need to OC it for your regular games.

[Smurph]

Supposedly DreamSNES runs better when OC'ed.

[ptr.exe]

dcmodder, where do you take the new higher clock signal then if you don't use an oscillator? there's the 54Mhz clock on the GPU but that's way too high.

Someone should compile all the info about OCing and make a really easy to understand guide, as (no offence to the author of the guide) the guide at DevCast is piss poor.

[dcmodder]

i dont know off the top of my head but if i were to see the tut.
the one on devcast is basically a translation of the one that everyone finds in japanese. all you do is lift part of the pin cominging from the 33mhz pin, and then take a wire from that and connect it to the 54 mhz graphics pin.

i understand the overclock method so i'll try to make some better (more understandable) pics.

[ptr.exe]

dcmodder that wouldnt work. Taking a 54Mhz clock signal and feeding it to the CPU, would give a CPU speed of (6x54) 324Mhz which the dreamcast cannot do unless the vCore is increased which can't be done. The highest achieved is 276Mhz.

Also by taking the 54mhz clock from the GPU, theres no pulse signal for the GPU so the DC wouldnt boot. Unless you 'share' the signal which ive never heard of anyone doing.

Royhubbs, you need the following:

1)A crystal osciallor (33+Mhz no more than 46mhz, most use 40)
2)Wire
3)Switch if you want to be able to go back to normal - although hot switching will 50% of the time make the DC crash.

[dcmodder]

you dont dis connect the 54 mhz pin only the 33mhz.

go here and you'll see what i mean.

[royhubbs]

and where might i get one? a radio shak ?

[HomerCIDAL]

I wondered that too and after visiting their site and looking for 40mhz crystal oscillator, I got about 51 returns for 40 watt this and crystal racing sets or walkie talkies. I'm not that savvy when it comes to finding electronics parts like this...thank heaven I can solder well enough when I finally find it!

[ptr.exe]

dcmodder, im well aware of the tut at devcast, and it doesnt say connect to the 54Mhz.

You don't understand, how on earth could you OC a DC using only a bit of wire and make it boot? Heres why it won't work really simply just for you:

Connecting the place that used to have the 33 (CPU) to the 54 would mean the CPU was fed a 54Mhz signal.
The CPU multiplier is 6, so by connecting the CPU to a 54mhz clock would mean a theoretical run speed of 324Mhz. Thats too high, the Dreamcast would not boot (work).
The highest working speed a DC can run at is around 280Mhz.

Show me any evidence of anyone that has OC a DC by that method to 324Mhz.

[royhubbs]

its all good, im putting in a mod chip, then maybe ill think about over clocking but well see... i just dont know what the hell im looking for.. i know i can solder and i can read schematics.. and follow directions, but finding the jiga ma flopper who knows

[HomerCIDAL]

BTW, can someone make a pic of the other side of where that wire goes to in the tutorial?

[dcmodder]

it goes to the 54 mhz pin. 1st pin on the same side of the clock chip. (from what i understand)

[ptr.exe]

it goes to the 54 mhz pin

NO IT DOES NOT

Seriously, read any topic on overclocking a Dreamcast, that will not work, 54Mhz is too high.

HomerCIDAL, solder the other end of the wire to the crystal oscillator that will generate the new clock, between 40 and 46Mhz is reccomended.
Also OCing wont work on a Rev.2 Dreamcast.

[Alexvrb]

I'd bet in many cases the SH4 itself could make it to 324Mhz no problem - it's all the other things that hold you back. You can't even touch the multiplier or the voltages. Also, where does main memory get its clock? It really isn't feasible. 240Mhz is a good target, because pretty much every DC should do that without any issues.

[HomerCIDAL]

GRRRR...ok, imagine I have never seen an oscillator before and don't know what to do with it. One side solders to the third pin after you terminate it's original connection. Where does the other side go? Where does the oscillator go? What else hooks up to the oscillator if anything. That tutorial, although seemingly well-written, is missing some vital information for someone that wants to try this but has never seen it before.

[ptr.exe]

Alexvrb, i think 324Mhz is just beyond the capabilities of the SH-4, possibly 300Mhz. But like you said there is so much other stuff holding it back in the DC, not to mention cooling, thats its just not possible in a Dreamcast, plus it's pointless :p

HomerCIDAL, this mod really should have a sign saying n00bs need not apply, no offense but its fairly simple.

On the osciallator you bought there will be a small black spot in one corner, this gives you a referance, depending on the oscillator you bought the following pins are in various places, one is power (+5v or +12v), one is ground, one generates the clock signal, the last one does nothing. Where you bought it from should have a data sheet/pinout.

Connect the ground and power to the PSU, then connect the clock pin to the DC where the old signal used to go. Done.

[Morphv2]

I actually made a quick replacement 33Mhz pin-guide, and offered it to him. he said he'd use it, but I assume he got busy.

here it is:

[Alexvrb]

Alexvrb, i think 324Mhz is just beyond the capabilities of the SH-4, possibly 300Mhz. But like you said there is so much other stuff holding it back in the DC, not to mention cooling, thats its just not possible in a Dreamcast, plus it's pointless

If you had an SH4 in a board without restrictions like we have in the DC, no memory or other components to hold you back, configurable voltages and multiplier, watercooling, I'm pretty sure the SH4 would reach a pretty high speed.

But none of that matters. Best case in the DC is ~280 at this point, although it varies from system to system.