What's with my 6800le's memory?

[aasmaukr]

I did som 3dmark05 benching with my 6800le today. I got a score of 5245 with the memory @ 950MHz, 3,1v and the core @ 445 MHZ, 1,3v.
The problem is, that the memory began clocking much worse after some hours with benching. Before, i could clock to about 870MHz, but now i can only get up to 820 (@ stock voltage).
I have cleared cmos, flashed back to the original 6800le bios, picked off the mem voltage resistor (the vmem mod) and reinstalled the nvidia drivers, but none of these things did help.

I hope that someone could help me fix this, 'cause i really want to beat the wr with this card...

I'm sorry, my english sux.

[***Deimos***]

Let me the first to say:

How in the world did you get 445Mhz GPU with only 1.3V??
And DDR950 on the memory.. wow!! The default is like DDR600 isn't it?

I think you may definetly be overheating that DDR, especially since you are running a dangerously high 3.1V. What cooling are you using on the GPU.. and what cooling on the VRAM? Also, what timings did you use for that VRAM?

[aasmaukr]

Let me the first to say:

How in the world did you get 445Mhz GPU with only 1.3V??
And DDR950 on the memory.. wow!! The default is like DDR600 isn't it?

I think you may definetly be overheating that DDR, especially since you are running a dangerously high 3.1V. What cooling are you using on the GPU.. and what cooling on the VRAM? Also, what timings did you use for that VRAM?

1,3v = 1,4v in the bios.
Default mem frequency is ddr700.

The momory is running cold with a 80mm fan. After what i have read, the maximum voltage of this memory is 3,6v.
I use a old Athlon 1ghz boxed cooler on the gpu. I used the stock timings.
I did DDR995 @ 3,3v, but i don't want to run at such high voltage...

Anyway, the memclock problem is gone away, i don't know why... I'll try to get some good 3dmark05 scores tomorrow.

[Highland3r]

3.1v is quite a bit for DDR1, you need some decent cooling and a high 3.3v line to pull it off, but if the ram continues to scale then...
Had 3.3ns DDR1 on the 4200 up to ~ 375mhz with 3.2v before, but it took some decent cooling, and mem wasn't massively happy after either...

[aasmaukr]

Seems like i've got the memory problem again. I can't get any further than 825MHz with 3v vmem.

[ChronoReverse]

Let me the first to say:

How in the world did you get 445Mhz GPU with only 1.3V??
And DDR950 on the memory.. wow!! The default is like DDR600 isn't it?

I think you may definetly be overheating that DDR, especially since you are running a dangerously high 3.1V. What cooling are you using on the GPU.. and what cooling on the VRAM? Also, what timings did you use for that VRAM?

Hmm. Probably overheating ram.

BTW, my 6800LE's memory can hit 920 easily at the default voltages so 950 isn't completely outlandish.

[aasmaukr]

No, the ram isn't hot at all.
I ram the memory @ 3,3v for a few minutes. I did 995MHz. This is with 2,8ns memory.

[iddqd]

I think the board is just dying on you. Video cards never take overclocking well. I mean, CPUs can last a couple years without showing a sign of wear... but with video cards, it's a gamble.

[***Deimos***]

I think the board is just dying on you. Video cards never take overclocking well. I mean, CPUs can last a couple years without showing a sign of wear... but with video cards, it's a gamble.

is he using the same timings for the memory in the BIOS.. that makes quite a big difference... (yes, even video card memory has timings!)

the other big factors off the top of my head are:

overheating (just because you think they are cool doest mean it is so.. any hot-spot can cause failure)

damage in the form of hillcok effect (sp?).. at high voltages, transmission lines and transistors can degrade due to the energetic electrons bumping the metal atoms, or breaking into the silicon lattive). This damage is irreversable.

power supply/ regulation problems. considering how high you are running over spec, maybe you just got lucky that the problem didn't present itself last time. Its well known that 6800 power circuitry cant handle both high GPU and high mem well... its a tradeoff.

drivers - I have had very good overclocking with 71.89 driver... however, the 77 and 78 drivers weren't good at all. There are some settings for BLITing that helped. If you have nForce3, I assume you know enough to turn off fast-writes... well actually it wouldn't hurt to turn it off anyway.