Need stability help at 200fsb

[gplracer]

I am having problems getting stability at 200 fsb synch. Currently my board is stable at 200x7.5. It will run prime 95 fine for at least an hour. It was stable before at 180x11.5=2079mhz @1.675v I tried to run at 200x10 @1.675v but it has problems with prime 95 giving me an error right away. It also sometimes has problems with 3dmark 2001 SE or some games. Is it possible that I need considerable more voltage to do 200 fsb instead of 180fsb at the same processor speed? Here is my specs:
1700+ B version week 51
8RDA+ 1.1 A1/C1 stepping
Gf4 4200
SLK800
Antec (Cheiftec case)
Kingston hyperx 3500 @ 2.77v

I tested the memory at 200fsb with memtest86 v3 and it is fine.

I am currently running stable at 7.5x200.

 

[MrEgo]

Some 8RDA's can get to 200MHz fsb no problem, but most others can't. I got lucky and was able to push it to 200MHz synced with my PC3200 DDR, but it won't go a single MHz higher than that, regardless of how much voltage I put to the processor. You'd need a way to add voltage to the northbridge to be able to push the FSB any higher and be stable. You should definitely go back to the 180x11.5 instead of the 200x7.5. Even though increased FSB helps out, 500 extra MHz would blow away a 20MHz increase in the FSB.

 

[gplracer]

I upped the voltage to 1.75 and now I am stable at 9.5x200. I will try this for a while and then go back to 10x200 and try it at 1.75v.

 

[ianching]

Oh, looks like I'm also having the same problem......

System Spec:
TBred B 1700+ DLT3C 0308RPMW
Alpha PAL8045 w/ 43CFM Elanvital fan
Epox 8RDA A1/C1 stepping w/ 3305 BIOS
Samsung PC3200 512MB (Single Channel)
Chieftec DX-01WD + 3 case fans
Enermax 330W PSU

As soon as I got my board, I cranked it up to 200FSB and it run flawlessly (10*200=2GHz, default Vcore), tried overnight loops of Prime95 together with 3dmark and it's fine.

However, when I get it to 10.5*200, it will fail even with Vcore at 1.85V, wierd thing is that I'm currently running the CPU at 2.3GHz 1.7V (but FSB at 184MHz) without a single problem, again, it passed 10hrs of Prime95.

What's up? It won't do 200FSB when processor speed is too high (>2.1GHz in my case). Temperature readings are good enough for overclocking and memory timings are by default and in sync. It just won't do 200FSB when I have the processor >2.1GHz, while it run flawlessly at 2GHz (10*200).

A quick look at MBM5 reports that the Enermax PSU readings are flunctuating a bit on all the rails except VDD and VDIMM. I suspect it's the PSU, anyone have a clue?