th7-ii RDRAM memory timing

Scalia · Jan 22, 2003

Use wpcredit to set value of the 850 chipset register BEh to 8A will increase your memory overclock because by doing such, you're increasing the RDRAM delay from 7/8 to 9/8.

I increased the stability of my p4-m overclock at 185 FSB by 1) booting at a lower FSB at which the memory works, 2) Use wpcredit to set the register value, 3) use setfsb to jack up the FSB.

Good luck and Enjoy!

Scalia · Jan 22, 2003

I wonder if Mr. Natural could incorporate this in the next version of the modded BIOS

Jirnsum · Jan 22, 2003

Sounds interesting. Anyone else who tried this?

About Mr. Natural. He hasn't been seen in ages, and all he did is what a lot of others here can do: setting some options that are already in the BIOS, but not visible in the Softmenu (which you use to set options in your BIOS). As nobody ever mentioned this setting, I do not think Mr. Natural or anyone else can put it into a BIOS without assembly coding.

ivanjong · Jan 22, 2003

well i can do this. but last i tried this last time the system will hang. so it doesn't hang on your system scalia ??? i need info on your system please. thanks .i'll get back to everyone as to if i can release that bios, very interesting

ivanjong · Jan 22, 2003

and may i know if you set the BEh register to 4A ?? last i checked this may not be a valid data to set in the register. i've read the i850 chipset datasheet. i'll recheck and try again later.

Scalia · Jan 22, 2003

Setting the BE register of the 850 chipset from 4A to 8A changes the 7th and the 6th bits to 1 and 0, which in turn changes the RDRAM delay. This is documented in the 850 chipset datasheet. Did you change the wrong register? It works perfectly fine on my mobo. You may want to try to just set the two bits instead of the whole byte.

This can be verified by running sandra, under mobo info you will see RDRAM timing delay going from 7/8 to 8/9. In any case, the delay is automatically set at 8/9 if you set the RDRAM multiplier to 4X.
This may be one reason why on some other 850 mobo you need to set 800 for PC1066 RDRAM module to get a good overclock.

Scalia · Jan 22, 2003

Let me clarify this:

Your RDRAM has to be running at 3X(with delay 8/9) so that you'll see any benefit so as to run at a HIGHER FSB.

Good luck.

ivanjong · Jan 22, 2003

i see. my mobo is already running at Pc1066 with ram multi plier set at 4X so thats why i get no difference and the system will hang if i try but theres no reason for me to run at 3X because i can run at 4X at full Pc 1066. but does all of you guys want this bios mod ???? i can do it if it needs to be done. oh yeah scalia on my mobo the register is set to 89 rather than 8A with ram at 4X. please confirm

Scalia · Jan 22, 2003

Correction: 4A -> 8A and not 8A -> 4A

I've been doing some experiementing, and found that the BIOS sets bits 5-0 to 9 hex when the FSB is between 133 and 166, and to A hex when FSB is above 166. I don't know exactly why this is so but maybe someone else could play around with that to see if we can get to an even higher FSB.

Before this, we have:

1) 3X RDRAM mult. with 7/8 delay
2) 4X RDRAM mult. with 9/8 delay

Now we have two additional options:

3) 3X RDRAM mult. with 9/8 delay (good for high FSB)
4) 4X RDRAM mult. with 7/8 delay (good for high performance at low FSB if your RDRAM works at such delay)

Scalia · Jan 22, 2003

I have successfully captured a shot of TH7-II running at 200FSB(800 quadpumped) running on a pair of Samsung PC800 45NS 128MB modules. Now this is using a p4-m 1.6g. But it is not stable yet. Maybe someone can let me borrow his/her PC1066 so that I can get more better results

I don't have a site to host that shot so if anyone wants to see it, I'll email it to you.

flapperhead · Jan 22, 2003

that is absolutely incredible!to get that kind of speed from45nschips!

Justin2050 · Jan 23, 2003

Scalia said:
I have successfully captured a shot of TH7-II running at 200FSB(800 quadpumped) running on a pair of Samsung PC800 45NS 128MB modules. Now this is using a p4-m 1.6g. But it is not stable yet. Maybe someone can let me borrow his/her PC1066 so that I can get more better results

I don't have a site to host that shot so if anyone wants to see it, I'll email it to you.

I have a c1 1.8a and im able to get upto like 170 fsb (3.06ghz) with my ram at 3x I would definitelty like to see and test one of these bios's I have 512mb of 45ns samsung in 256mb sticks

Scalia · Jan 24, 2003

I'm using the 40B BIOS and not getting the PCI/AGP lock like the mobo is supposed to have. I tried fixed, 2/5, 2/6 options but they don't work past 166FSB. Does anyone have a solution for this?
Fixed option for PCI/AGP will lock up booting to windows when FSB is above 170. And I had to use 2/5 to boot to windows but under setfsb it showed a 2/4 PCI/AGP divider rather than 2/5.
Believe it or not, I/O is rather sluggish when the FSB is set too high. I don't know why this is so though. BTW, I tried all other BIOSes and the situtation is pretty much the same. I'm beginning to believe that this board does not have a divider that is greater than 2/4, other than the "fixed" which doesn't work beyond 166FSB.

Jirnsum · Jan 24, 2003

The newer BIOSes DO have them.

It is true that PCI/AGP lock doesn't work for the 40B.

th7-ii RDRAM memory timing

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