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MAXIMUSpowers
October 16th, 2009, 18:55
Hi, Since me and Spinksy seemed to get a little off topic in the SD card thread I have decided to start a new thread here.

Im really wanting to overclock my dreamcast but id like to know a few results of various clock speeds.

Ideally id like to overclock my Dreamcast to a speed that it can function at all the time so that I dont need a switch. This would also increase data integrity. I know that there are issues with the VMU when the DC is running at 240mhz but I have never heard of any results from lower clock speeds.

Does anyone have any results of clock speeds between 200mhz and 240mhz with specific regards to VMU functionality?
BlueCrab
October 16th, 2009, 20:14
Moved to Hardware....
MAXIMUSpowers
October 16th, 2009, 20:50
There isnt a hardware section though, Not that displays on my PC. Send me a link to it as i cant see it
MAXIMUSpowers
October 16th, 2009, 20:52
Found it! Its not even in the Sega section though!
spinksy
October 17th, 2009, 00:57
I was thinking of starting a new thread :rolleyes:

Honestly mate if you are going to overclock it I would definatley put a switch in. 240mhz plays very well - my mates always want me to take my DC round theres all the time now as they like the difference.

It just seems alittle silly not to bother with a switch - its hardly no extra work an will give you peace of mind.

The memory card I'm using that works at 200mhz and 240mhz is a cheapy (non screen) memory card I kinda bought by accident from the US on ebay. (it has an orange sticker on it that simply says 'MEMORY CARD, PERFORMANCE. For use with Sega DREAMCAST')

Let me know if you do it and how you get on.

Oh and btw I finsihed my internal VGA mod and the picture difference is unbeleaveable!!! I've soldered in the wires for the internal card reader but need to find a simple wiring diagram to do it)
MAXIMUSpowers
October 17th, 2009, 16:20
Spinksy give me your email and ill send you the diagram
spinksy
October 17th, 2009, 23:36
pm sent;)
MAXIMUSpowers
October 19th, 2009, 18:18
If I was to overclock my VMUs would they work when the dreamcast was running at normal speed?
spinksy
October 21st, 2009, 22:01
I don't know.


But to be honest - who cares. You can get VMU's for peanuts these days. I've got about 15...
MAXIMUSpowers
October 27th, 2009, 13:19
Hi Spinksy. Ive overclocked my dreamcast to 230mhz but found that nearly every game ive tested crashes. The soldering is pretty good so it cant be that. The clock feed cable is about 3cm. The board is a VA1. I dont own loads of games but the ones that I have tested that have crashed are: 355, Sega Rally 2, Crazy Taxi, Half Life, toy commander, toy racer, revolt.... Basically 90% of my games dont work without crashing. Can you test any of these games if you have them.

Do you find that most games crash? If not does anyone have any suggestions as to why this is happening
wildwestwind
October 27th, 2009, 14:14
test
MAXIMUSpowers
October 27th, 2009, 14:16
Ive put it back to the original clock speed and all seems to be well again. Do you think it could be the crystal I have used? Heres what it says on it: GBS 205c, 38.4MHZ. I bought it from Ebay : http://cgi.ebay.co.uk/1x-CRYSTAL-OSCILLATOR-38-4mhz-38-4-mhz-GBS205C_W0QQitemZ170248624487QQcmdZViewItemQQptZUK _BOI_Electrical_Components_Supplies_ET?hash=item27 a39bd967

What crystal did you use spinksy?