9800 XT (Pro) Volt Modz, AGP VDDQ????

[-=j0nnyr0773n=-]

I have just performed the memory and core volt mods on my 9800 XT (Pro) and upped both my voltages from 1.7 and 2.7 to 1.9 and 2.9. Ever since then I cannot prime95 for more than 30-60 minutes. I have tried many combinations of AGP Vqqd and Vcore settings and still no go. Before the modz I wuz able to prime all day and nite solid. Any suggestions?

-=j0nnyr0773n=-

[Hellraiser1981]

If you did the VDDQ mod without doing the VDD mod, you'll have stability problems.
Do you have a good enough cooler for 1.9v? (it should be liquid cooled at 1.9v)
I have a vantec tornado cooling my 9800 and I don't dare go over 1.85v
What about ramsinks on all the BGA memory chips?

VDD is the main voltage of the DDR
VDDQ is the voltage for the memory input/output buffers

When I modded my 9800 pro 128M, VDDQ mod only hurt the overclock, so i usually leave that switch off. (I hav a set of 4 switches so i can turn each mod on and off)

[-=j0nnyr0773n=-]

Hey thanx 4 the reply. Yes I performed both mods, and I have an Arctic Cooling VGA Silencer and copper ramsinks on all 8 memory chips :) I did notice that it was fairly hard to keep the temperatures from skyrocketing, so I have the VDD back down to 2.82v and the VDDQ back to 1.77v. That's where they started @ when I hooked up the resistors with a resistance of 20k. Actually the VDD started a little lower than that but I thought I'd up it a little. The heat it was producing was not worth the small overclock I could get. 424/384 :( I was hoping to at least get the mem to 400 and the core to 435. I can actually run it at those speeds, but 3dmark01 gives artifacts and snow. Anyways, I think I might remove the VDDQ altogether and just keep VDD @ 2.82. My blue screen problems were because I had corrupted my operating system. I fixed that up and I'm rock solid now. What do you think about me removing the VDDQ mod and keeping VDD @ 2.82? Seems stable now with it turned down.

-=j0nnyr0773n=-

[Hellraiser1981]

Yeah, you should remove the VDDQ mod, Ive never seen it make a positive difference.
BTW, I've also tried lowering VDDQ and VREF below stock, also with no positive results; stock voltages seem the best for those.

The VDD mod on my 9800 pro only gives about 5Mhz extra on mem.
VGPU is the most important one.
435/400 is really reaching for the sky (unless your card was blessed by the memory gods)

I can get 430/370 out of my heavily modded 9800 Pro. (stock hsf with 80mm tornado zip-stripped to the card :D )
Did you try a bios mod to improve your overclock?
I used a powercolor 9800 pro 128M bios and it brought my max clocks from 420/365 to 430/370 ; the freqs I was shooting for. Soon I will be adding a Zalman ZM80D Heat pipe cooler with ramsinks. Hoping for 450/375

Also, remember Copper Ramsinks remove heat from the mem faster, but aluminum dissipates heat into the air better. Aim a fan at the entire card/ramsinks and see if it helps.