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View Full Version : Questions for people who have overclocked their DCs.



quzar
July 4th, 2005, 20:35
I would like to try to get a fair list going of who has, what clock speed they run it at and wether or not they used any sort of modified cooling. Basically I'd like to see about doing this myself eventually and want to see how the numbers pan out.

So, if you have overclocked your dreamcast, please put the clockspeed you have reached (cpu, gpu or both), if applicable, what speed of a clock generator you used, and what other modifications you made in terms of cooling.

Thanks a bundle (I may or may not start a little list in this post of everyone depending on the responses I get).

ptr.exe
July 7th, 2005, 18:32
The so called GPU OC is actually a pixel clock and so is pointless unless you wanna screw up refresh rates.

I had a DC OC'd to 240Mhz, but its toast. The C/O is screwed and now i cant get it to boot even on stock 200Mhz. i didnt use any extra cooling as most said for a low 240 OC none was needed - this may have caused the DC to fry, i dont know.

Meshuggah27
July 9th, 2005, 04:03
I agree with lynch. It is pretty pointless.

ptr.exe
July 9th, 2005, 15:38
I agree with lynch. It is pretty pointless
wtf!? thats not what i said.

The GPU overclock is pointless as it has now been proved that the 54Mhz clock is the pixel clock so OCing it just messes up the refresh rate.

Overclocking the CPU (and everything else in turn) is well worth it. I merely suggest adding some cooling as to not fry your DC like i did.
For commercial games it will stop slowdown on all but the most demanding games, and for homebrew it does make a differance but the biggest improvement is for emu's, DreamSNES on a 277Mhz OC DC is pure gold, very little slowdown, demanding games such as CT will still hover around 85% but it wont suddenly drop through the floor to 30% when a fight is starting. Be warned though as some games/emu's do not like running on an OC'd DC so keep a switch to turn back to the normal 200Mhz.

Morph
July 9th, 2005, 18:28
And as a note, NEVER hit the overclock swicth WHILE the DC is running. That are bad.

ptr.exe
July 9th, 2005, 20:44
Morph, i used to do that if it refused to save, although my OCed DC did fry, that may have been the cause.

quzar, these are two points you should be aware of:

- when your DC is OCed it is difficult to save, its like 50% if it will save or not, so sometimes you have to try a couple of times.
- you cannot hot switch between 200 and OC speeds when the DC is on, because for the split second the DC has no clock the DC will reset. Sometimes it will work, and i found that if you went into a menu, and flicked the switch fast it sometimes worked.

those are the only negative aspects, and also invest in an extra fan.

Morph
July 14th, 2005, 19:29
Hell, invest in a broken Dreamcast, and about 3 (more if you are not that fast) hours of your life and make a GD-Rom cable like I did. Then you can heatsink/fan the CPU and GPU and you can do some SERIOIUS hardware work.

quzar
July 14th, 2005, 21:26
The reason I asked was because I have a LOT of broken DC's (it's about 20+ motherboards with only 2 or so working GD-roms) and can do a lot of toying with overclocking if I wanted to (since I don't have to worry about the motherboard itself).

I think it would probably not be that difficult to get the SH-4 running past 300 Mhz with a combination of real cooling and possibly a voltage mod.

I know I'm not seen around these parts much but I know my way around DC hardware. One of my projects long ago was building a Dreamcast into a 5 1/4inch bay and making a new PSU for it from scratch that would run off a standard PC molex connection. I was able to do both except that I was never able to run the dreamcast off the molex because I didn't get enough current to let it boot (I could get the light to appear for a moment then power would cut out).

ptr.exe
July 14th, 2005, 21:32
im in need of a working A01 mobo, care to donate/sell? PM me if you're interested.

quzar
July 14th, 2005, 21:38
i'm not looking to sell any parts at the moment, but I will eventually. When I got them i recorded which parts worked and didn't and specific problems etc, but i lost where i wrote all that down, so i don't know what is there and such. Also, i've been really busy with life. Hopefully by the october or so i should be settled back in (leaving college, getting a job, starting at a new college, getting a car etc). Whenever it is that I go for it I'll make it well known.

Darksaviour69
July 15th, 2005, 12:52
some german guy is selling an over clocked dc 240mhz
http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&category=4313&item=5219608124&rd=1

it was posted over at dreamcast-scene
http://www.dreamcast-scene.com/community/viewtopic.php?t=190

ptr.exe
July 15th, 2005, 12:58
It's such a simple mod that there is no point paying over the odds for an OC'd DC.

It took me 5 mins to OC mine, nice easy mods and useful for homebrew.

Darksaviour69
July 17th, 2005, 14:14
the guy over clocked the vmu as well to match the dc...

ptr.exe
July 18th, 2005, 14:31
now that's impressive. I really wish there was a tut. for that, saving on an OC'd DC is a bitch.

EDIT: Actually bothered looking at the eBay link, that is worth paying over the odds, its a really professional job, that heatsink is quality.

Morph
July 20th, 2005, 02:50
Yeah, I'm impressed. Wonder if anyone has tried heatsinks and fans on the chips *cough* >.> .

quzar
July 20th, 2005, 03:58
That's exactly one of the questions I was asking.