Unable to reach 200 FSB with new unlocked 2500+. What's holding me back?

[BlueWeasel]

Here's what I've got:

Epox 8RDA (not sure about revision, got it this time last year, CPUz reports A2 chipset)
1024mb RAM (2x256 PC3200, 512 PC2700)
Barton 2500+ (unlocked week 32)

Because of my mixture of PC3200 and PC2700, I was planning on run the CPU at 200 FSB and the RAM at 166 until I get some more PC3200.

Based on what I've read, I was expecting to pop the 2500+ in and simply bump the FSB to 200. Well, it didn't go that well. Currently running at around 180-185 FSB using the default voltage. However, it's not stable at 190 or higher, regardless of the Vcore or Vdimm voltage I've used (up to 1.8v and 2.8v). I've even used a single stick of the PC3200 with conservative settings, and it's still not stable.

I don't think it's the CPU or the PC3200 that would cause problems above 190 FSB. I haven't found an exact answer yet, but it may be because of the Northbridge limitations of my particular revision (probably v1.0 or 1.1) on the 8RDA.

What am I missing?

Will I have to do the voltage mod. to get this board to reach 200 FSB stable?

 

[Duvie]

The early revision baords could be the issue as these things were not necessarily made for 400fsb chips and therefore the northbridge couldbe flaky at these speeds....Does the mobo have a chipset vcore beside the cpu??? If so bump that up a notch and maybe pop the heatsink off and apply some AS and maybe a better fan....


Also I think it is really to earlt to tell and way to early to rue out the cpu....Cmon ppl not all 2500+ bartons can make it to 200fsb...I mean amd doesn't get perfect yields...This may have just been one of thefew chips that did not clock well and hence was marked at the lower speed....

I think you lack any credible evidence to do such a thing...It is more likely it could be the early revision mobo, but short of geting a new mobo to test it out that is hard to identify....


Here is a thought....Can you do 2200mhz with say a 166fsb and a 13.5 multipler or a 183fsb and a 12x multiplier??? If you can't do the 166 then it is likely just the cpu....

 

[Megatomic]

Duvie, you are correct on many accounts there. I had an older 8RDA+, one without the newer chipset so 200MHz FSB was NOT guaranteed at all. I was able to get my system up to 195MHz FSB but anything higher than that was impossible. The reason? No Vdd adjustment in the BIOS. Vdd was about 1.5V, probably .2V too low for 200MHz FSB.

BlueWeasel, your options are this:

1. Do the Vdd mod on the board.

2. Buy a newer NF2 board with the NF2 Ultra 400 chipset.

Sorry man.

 

[Killrose]

I had to mod my 8RDA.

 

[osage]

(2x256 PC3200, 512 PC2700) are you using the pc3200 with the pc2700 ? ? if so loose the pc2700 and try it with just the ram that supports 200 mhz fsb.