Epox Tech, please help -> EP-4T2A3

[Sampsa]

Dear Epox Tech,

Ok, now comes a little more technical question..

I have been testing EP-4T2A3 motherboard few days now and as you know it's based on i850 chipset and RDRAM-memory.

I have now tested and noticed that 3,3V line somehow affects to memory bus, and here are my testing results (memory running at 4x):

Raising the 3,3V line from Forton Power (limit is 3,9V) HELPS raising the Front side bus.

3,3V -> 119MHz
3,6V -> 127MHz
3,76V -> 129MHz
3,79V -> 131MHz
3,89V -> 133MHz

Ok, now the BIG question is.. what does this 3,3V line control? What component does it affect SO much that you can see so big difference when raising the 3,3V line from power supply.

Any information is more than welcome. For example, circuit diagram of EP-4T2A3 HIP6521 chip or something.

Now here is the plan what we are going to do after we figure, where does this 3,3V line affect. We will modify the input so, it will make a voltage from +5V line and so we are able to supply more than 3,9V which is the limit of power supply.

Please answer are you able to help us or not.

Thanks!

[Nitza666]

It controls the chipset VIO and memory voltage and 3.9V is extremly high and you will burn the chipset,memory very soon.Use a maximum of 3.65V not higher.

[EPoX Tech]

Originally posted by Nitza666
It controls the chipset VIO and memory voltage and 3.9V is extremly high and you will burn the chipset,memory very soon.Use a maximum of 3.65V not higher.

Thank you "EPoX Tech", have I changed my ident.

[Sampsa]

Epox Tech, Do you agree this? Or have any opinion?

[EPoX Tech]

You will ultimatley raise the voltage of all devices that use reference of 3.3v supply - that means memory v.reg, agp card, northbridge, raise split-plane current etc.

It sounds great to up the ante on all of these components however it does mean that a strain would be administered.

The voltage of 3.9v is not what you want to increase from the PSU but moreso the VRDIMM voltage directly from the memories VReg. I don't however have the board at hand to take a look at how to modify on the board. Upping the RDRAM voltage rather than all reffered 3.3v ranges will lessen the strain on the mainboard whilst still adressing the correct area.

Do please remember that your RDRAM is costly, as is your i850 board - don't hurt it too much !!

[Sampsa]

Epox Tech, Heh don't worry.. this is my fulltime job as webmaster of largest hardware and overclocking site in Finland

(So if I can figure how to solve this, there will be many happy EP-4T2A3 motherboard owners in Finland)

But anyway..

If I set 3,3V to 3,3V from PSU and supply 2,9V from bios to RDRAM the limit is 119MHz front side bus.

If I set 3,3V to 3,9V from PSU and supply 2,5V from bios to RDRAM the limit is 133MHz front side bus.

Few other things I have noticed:

If I set memory to work 3x CHIPSET is able to work FINE above 133MHz... so chipset isn't problem.

Somehow this 3,3V line affects to memorybus but it isn't VRDIMM voltage..

Epox Tech, Are you able to get any datasheets or something

Here is an image of regulators near RDRAM-memory slots. BTW, For what use is that PW3-connector which is removed?


http://www.muropaketti.com/temp/ep.jpg