Abit AB9 Pro & Micron D9GCT overclocking issues

[pasatoiutd]

Setup:
Abit AB9 Pro Rev 1.0 + BIOS 1.5 or 1.6
Conroe E6600 L632B064 + Thermaltake Big Typhoon * 80CFM fan
2*1GB TeamXtreem PC4300 3-3-3-8 D9GCT (2 kits)

When testing with 3-3-3-x (x=3,8,9) timings, the dimms behave as they should. One kit goes up to DDR800 @ 2.4V - DDR820 @ 2.5V (orthos stable for ~30 minutes), while the other reaches DDR780-DDR790 using the same settings.

When changing the lattencies to 4-4-3-11, the better kit scales quite well at low voltages, reaching DDR890 @ 2.05V (BIOS setting) (2.01V-2.04V real voltage during load). At these settings (DDR 890 4-4-3-11 @ 2.05V) the 2GB kit is Orthos stable for more than 8 hours.

AND NOW THE PROBLEM: after DDR890-DDR900 the stability decreases rapidly and things aren't any better if I change the settings to 5-5-5-15(18) and increase the voltage to the maximum the board allow me to use (2.5V). From what I've seen, the D9GCTs, in general, and this kit in particular reach about DDR1000-DDR1150 with 4-4-4 or 5-5-5 and 2.4-2.5V on Asus P5B-E/P5B-Deluxe

I suspect a motherboard issue/partial incompatibility ... Any advices ?

[saboya]

I have 2x1gb D9GCT and AB9 as well, and had the same problem... It's probably due to low vmch. You need vmch mod.

[ownage]

I did some Team pc6400-cas4 (TXDD2048M800HC4DC) and AB9-Pro action, only could do 1060 max cuz stable(5-5-5-15) i believe, but didn't have enough time to test more.

Its logical if the AB9 cant clock the memory as high as the P5b, duo to the 1333 strap the P5B has. Memory clocks much better with the 1333 strap.
But 1000mhz should be easy i think.

[Evilsizer]

no i think it might be something else.
http://img.photobucket.com/albums/v733/Evilsizer/ocforums/superpi%201m%20runs/34g1140g.jpg
but then my ram is promos based, have yall hit the abit.com.tw site to get the 1.7 bios for the ab9's?

*edit*
well D9's run hotter then the promos i have on my board. so i ask do you have the ram activly cooled? if not then i think the heat from high speeds/tight timings/high voltage is getting to them.

[pasatoiutd]

I've tried 1.5, 1.6 and 1.7 BIOS versions.

Using the 2:3 divider, the memory does memtest @ DDR1002 4-4-4-8 @ 2.3V for many hours, but Orthos fails within seconds at anything higher than ~ DDR920.
The same RAM (TeamXtreem PC4300 3-3-3-8, Micron D9GCT) did SPi @ DDR1090 4-4-4-4 @ 2.4V on a 680i board, using auto settings for the memory subtimings.

Using TeamXtreem PC9600 5-5-5-15, with D9GKX chips, it's clear that AB9 Pro has difficulties in clocking the RAM higher. The RAM stops ~ DDR1120, no matter what voltage (<2.5V) and lattencies I use ...

[Evilsizer]

the question still begs to be answered did you guys use active cooling on the D9's when pumping 2.4v+ into them when clocking 1.1ghz+?