P5B Deluxe: run FSB at 400 (1066 Strap) or 401 FSB (1333 Strap)

[Jumpem]

It seems I can have my ram at 4-4-4-10 on the 1333 Strap, but 5-5-5-12 on the 1066 Strap.

 

[myocardia]

That's because running at the extreme high end of a strap is much, much harder on RAM than running at the extreme low end of the next higher strap.

 

[The-Noid]

It has nothing to do with the ram. You are overclocking the northbridge, that is what is causing the instability. You seem to have answered your own question though .

 

[Jumpem]

So I am better off on the 1333 Strap at 4-4-4?

 

[The-Noid]

yes, for sure. You will lose a bit of performance but you will pick it up in stability. Also chances are you will be able to hit much higher fsb. So you can do 500+*7 or such.

Also it is a 1600 strap not a 1333 strap. Everyone thought it was a 1333 strap because the badaxe 975x had it. Check out thetechrepository.com. It is written by a couple of people that work at OCZ that have proven it has a 1600 strap rather then 1333. Explains why 1066/4 = 266, 1600/4 = 400. That is why it cuts out at 401.

 

[cmdrdredd]

I run 5-4-4-8 on 400Mhz FSB right now and it's stable. Not everyone has the same luck. Gotta go with what you can get.

 

[The-Noid]

If you are running 4:5 on 400 mhz your motherboard has already strapped over around 380... running different fsb:ram ratios will cause your motherboard to change strap earlier. Otherwise your northbridge would be running around [(400*1.25)-266]/266 = 87% percentage overclock which is just not possible, without some much better cooling.

This is why I would like to see bios source code release to public, but it also would not be good as virii would become more prevalent.

 

[MADMAX23]

If you lower (relax) by 1 or 2 ns (from 10 on) the two settings in black listed below, you'll gain stability, no matter what strap you'll be using, it will help gain stability and will not hurt performance at all. Check my Bios settings below. (Note my system is 24 hrs blend test stable with both configs, 3.2Ghz amd 3.6Ghz)

-------3.2 Ghz Config------

Chipset ---------DDR2 800 (400Mhz x 2) 1:1

Northbridge
Memory Remap Feature....Disabled
CAS latency (CL)...............4
RAS to CAS delay (tRCD)...4
RAS precharge (tRP)..........4
Activate to Precharge............12
Wrire Recovery time ........2
DRAM TRFC.....................30
DRAM Act to Act Delay TRRD....2
Rank Write to Read Delay.....9
Read to Precharge Delay......1
Write to Precharge Delay......10
Static Read Control..........Disabled

Sisoft Sandra Memory Bandwidth:
7165 Mb/s
7182 Mb/s
Efficiency: 112%


------3.6 Ghz Config------

Chipset -------DDR2 900 (450 Mhz x 2) 1:1

Northbridge
Memory Remap Feature....Disabled
CAS latency (CL)...............4
RAS to CAS delay (tRCD)...4
RAS precharge (tRP)..........4
Activate to Precharge............12
Wrire Recovery time ........3
DRAM TRFC.....................35
DRAM Act to Act Delay TRRD....3
Rank Write to Read Delay.....12
Read to Precharge Delay......2
Write to Precharge Delay......12
Static Read Control..........Disabled

Sisoft Sandra Memory Bandwidth:
7475 Mb/s
7503 Mb/s

Also note the underlined Ram/chipset settings, they are set at 10 by default, but you can tighten them a lot and gain a very nice increase in performance, going over 7000 Mb/s in Sisoft Sandra Mem bandwidth test. My advice: Test with these timings once you have a stable system.

I could explain this a bit better, but unfortunately I haven't got much time right now. However, I'll keep suscribed to this topic so that I can help you when I got free time (I'm a young lawyer), ok?

Good Luck!