Wrote a small article on chipset strap etc

[Tony]

533 strap forces PAT on 865, asus found it and everyone followed.
CPC 1T on 875 etc it 1T but rarely works. DDR2 has no option at this time for 1T on an Intel chipset.

If you study the registers for PAT you will see its the same at 533(865) as 800 on the 875, so all Intel did was overclock the chipset to force faster memory access.

[_damien_]

Alright, thanks!

[hipogtr]

Thanx for the info. Quality post.

[jumanji969]

Great thread, glad we have posters like Tony willing to share their knowledge, and in a way for us simple minded folk .

[graham_h]

Thanks Tony. so whats the best setting on an Asus P5W DH Deluxe for high FSB ?

[Anemone]

Look forward to the followup. Thanks for sharing your considerable experience Tony.

[OBR]

Thanks Tony. so whats the best setting on an Asus P5W DH Deluxe for high FSB ?

Yeah, good question, answer anyone?

[graham_h]

We're still dying to know

[Tony]

The best setting would be force 1333strap on the CPU and clockgen but force 1066 on the chipset to keep the memory fast and run it 1:1.

The issue is we still have no way of telling what the board is doing with the straps.

[Shpoon]

Coming from A64, that's a great help, as straps confuse me...problem is, I'm still a little confused. Got any links that help explain the use of straps, and the connection between the cpu and chipset?

(I kinda get it...the cpu strap is the same for the chipset, so @1066, the NB is running at 267 with the CPU...but as you rais the FSB of the CPU, your NB rises as well, and you hit a wall when it gets much too hot, unstable, whatever. So if you put a 1333 strap, how does this help? @333mhz, why is it suddenly more stable than taking a 1066 strap and pusing it to 333 and above?)

Also, the RD600 is rumoured to go much above the 370ish wall...would they have the independent straps?

Fake edit: What exactly is the purpose of this strap though? If the chipset and the cpu run totally independant, is there a point where the difference in FSB becomes an issue, or is the entire problem arising because it's easier for manufactureers to set a single strap for both? Do the FSB ratios of both even matter?

(If I asked too many questions, please tell me to shut up, or google (though I tried) )

Edit: Still don't get it fully :p after trying to read some things. Default is say 1066, but you play with the FSB, and system bus speed changes. (fsb x 4, correct?), so you set it to 1066, up the FSB, the actual system bus changes...you set it to 1333, up the FSB, the system bus changes...what difference does it make?

[Tony]

Think of it this way:

The chipset has 4 working ranges for speed, these are dictated by the multiplier set for the clock frequency of the chipset.

The Clock generator for the CPU etc has the same 4 working ranges, these are dictated by the BSEL pins on the CPU..IE the strap it sets.

The ram speed ratios are dictated by the chipset dependant on what chipset multiplier has been set for its internal frequency.

Now: the chipset has a max clock just like a cpu does, as you ramp up the clock frequency you may have to lower the mutiplier...you do this by going to a higher chipset strap..IE going from 800 to 1066 etc.

The Clockgenerator has the same issues, its internal PLL has a max working frequency, when you change the BSEL strap on the CPU you actually reset the PLL but initiate the clock at a higher base setting...so, if you moved from 800 to 1066 the FSB working range may be the same 100fsb you have available going from 200fsb to 300 but the base clock the clockgenerator starts at has moved from 200 to 267 so instead of maxing at 300fsb you now max at 367fsb.

finally the lower the strap set the more aggressive the internal latency on the chipset, this means the ram is faster but may not do the tight timings or may not clock as high.Ram ratios are dictated by dividers preset within the chipset per the strap it is set to....1:1 at 800 strap will not be 1:1 on the 1066 strap etc.

Hope this helps

[cadaveca]

It does for me, but i think alot of people need a diagram as to what happens when you select what. Do you think it's possible for you to come up with something that we can use as a reference?

[Baldrick]

Excellent Guide

[Tony]

It does for me, but i think alot of people need a diagram as to what happens when you select what. Do you think it's possible for you to come up with something that we can use as a reference?

you want a picture also...ohh man...LOL

I wrote it as simply as i could, a pic will take time

[cadaveca]

no worries..i understand what's going on with the chipsets(it's like the AXP L12 mod, i'm sure), and you are busy. I just see ya typing the same thing over and over.

[pazza316]

Great Thread mate. Interesting read!

[ZBr]

Yes thank you tony, thank you for taking the time to clarify this!

[Tony]

Albatron had a board that featured a digital clock generator, we still have not seen the board in retail but i heard this clockgen alowed the CPU's there were testing with reach in some cased 400MHZ higher clock. They also found CPU's clocked better with less voltage and were stable right to the max of the working frequency.

I have a feeling if this board ever shows we may see some awesome clocks in 1066 strap.

[NiCKE^]

Sounds cool but words are just words And pictures says more then thousand words so hehe

I hope we will see it soon.

[Blacklash]

Very nice work. Thank you.

Asus seems to release a BIOS fairly often. It looks like they could provide a few options like the Bad Axe as far as straps are concerned. I can only select 1333|667 via an "oc profile". Doing this I lose a lot of control of other key things.

In addition, the 7950 GX2 has been officially support in the Bad Axe for a while. I know the 7950 GX2 works fine in the P5W DH Deluxe with the same chipset through experience. They ought to make that official. I thought nVidia and Asus were close and official support would have happened a long time ago. This makes for poor appearances.

[Shpoon]

Think of it this way:

The chipset has 4 working ranges for speed, these are dictated by the multiplier set for the clock frequency of the chipset.

The Clock generator for the CPU etc has the same 4 working ranges, these are dictated by the BSEL pins on the CPU..IE the strap it sets.

The ram speed ratios are dictated by the chipset dependant on what chipset multiplier has been set for its internal frequency.

Now: the chipset has a max clock just like a cpu does, as you ramp up the clock frequency you may have to lower the mutiplier...you do this by going to a higher chipset strap..IE going from 800 to 1066 etc.

The Clockgenerator has the same issues, its internal PLL has a max working frequency, when you change the BSEL strap on the CPU you actually reset the PLL but initiate the clock at a higher base setting...so, if you moved from 800 to 1066 the FSB working range may be the same 100fsb you have available going from 200fsb to 300 but the base clock the clockgenerator starts at has moved from 200 to 267 so instead of maxing at 300fsb you now max at 367fsb.

finally the lower the strap set the more aggressive the internal latency on the chipset, this means the ram is faster but may not do the tight timings or may not clock as high.Ram ratios are dictated by dividers preset within the chipset per the strap it is set to....1:1 at 800 strap will not be 1:1 on the 1066 strap etc.

Hope this helps

Perfect, thanks

[girth_maul]

Nice little guide, esp for an AMD user.

[Cooper]

What we also need though is the ability to set the NB strap to any option we want also, independently to what the CPU strap is, this would allow us the option to over clock the NB its self. Finally the option to adjust the NB latency, like we had in “875 tweaker”

Something tells me that RD600 will have these options (or something like that) build-in - the only explanation for independant memory and CPU frequencies I could guess of

[FLMJIGGY]

Nice little guide, esp for an AMD user.

Yes without a doubt. MANY THANKS!

[Tony]

Updated the guide with special ram ratio info and how it effects overclocking.