I/O voltage vs. VCore

[gyoung]

I have a question about the I/O voltage. I did a search for it and found that it controls the voltage to the peripherals (PCI, AGP, Memory, Chipset). Does the VCore only control the voltage to the processor?

Is there a resource on that explains all this?

 

[AndyHui]

VCore only controls voltage to the processor. That is correct.

VIO controls voltage to the PCI slots, AGP slot, DIMM slots and chipset.

 

[gyoung]

So my assumptions are correct. I have a Duron 600 running at 884 (104Mhz X 8.5), it is completely stable at this speed or 850Mhz (100Mhz x 8.5). I can do this at a Vcore voltage of 1.65 and be perfectly fine. However, I cannot run using the 9x multiplier at all. I've tried everything. I bumped the Vcore to 1.85V (max) and set all the memory timing to the most conservative settings. The only thing I haven't tried is changing the I/O voltage.

I haven't done this because I don't know what it is/does. I figure if you don't know what it is ask first. So I'm asking. Would this get me over the 900Mhz barrier? When I try the 9x multiplier it freezes while at the Windows 98 login screen. It does the same at 9.5x also. If I try 10x it won't even post. So would upping the I/O voltage have any luck?

 

[White Widow]

My guess would be that upping to I/O voltage will not be too fruitful. My understanding is that no one has ever been able to document the benefits of increasing the I/O voltage. It just "seems" like it could/should be helpful.

If your computer is freezing during the Win98 bootup then I would be looking at either the CPU or the memory as the problem. If you are sticking at or near the 100fsb mark, then it's not your PCI/AGP peripherals that are causing the trouble. Similarly, if your RAM is even decent, it should be able to handle any fsb at or near its rated speed.

Your chip is probably just not going to go any further...without more cooling. Try getting a larger HSF for your Duron. What are you using now? Anecdotal evidence suggests that the .18u Duron core will "take advantage" of extra voltage all the way up to 2.1v or 2.2v as long as there is sufficient cooling! Personally, even with a nice FOP38 or large Alpha, I wouldn't push the chip past 1.85v-1.90v if you want it to last for more than 6 months. As is, at 1.85 volts your Duron is probably just overheating.

Hope that helps,
Aaron

 

[gyoung]

I'm using a Alpha PAL 6035 cooler with generic thermal paste. I'm also using PC133 Crucial CAS2 RAM. So I think it might just be the limit of my CPU. Not a big deal. I was just trying to see if there was anything I was missing.

How do you get your voltage above the 1.85V cap?

Currently I am stable at 8.5 X 104Mhz = 884Mhz @ 1.7V. This means my memory is running at 138Mhz. So it's not too bad for a 600Mhz chip!

 

[Preyhunter]

Getting your board above the 1.85V limit depends on the board. Some boards will go beyond that in their normal production configuration. Obviously, yours will not. Some boards can be modified to go beyond that cap. I only know of a few boards (2 I think) that have the instructions on how to modify the board in order to get over 1.85V, one being an ASUS A7V model. This does require small component soldering and may not be too desirable if you are not comfortable with doing this modification. There is a site that sells modified boards, but they carry no warranty and many people from this site would not recommend doing business with them, though I just received a board from them (not a modified board) and have been very pleased with it.