Overclocking a 3Ghz P4C memory problems?

[Degas]

Hi all, this is my first post here I hope you can help.

In my PC I have some Crucial 3200 DDR memory, the rest of my sytem is as follows:

Asus P4P800
P4C 3.0Ghz
9800 pro
120Gb & 80Gb SATA.
etc

Using the automatic overclock feature of the mobo's bios I am overclocking by 10% thus the P4 runs at 3.32Ghz. The temps are fine and dandy but my 3Dmark score was somewhat unremarkable. I ran Sisoft Sandra 2004 and found the problem, my memory was only running at 146Mhz which is obviously incorrect. If I only o/c the system by 5% the the memory runs at full speed ie 200Mhz. Does anyone know a workaround to this problem.

Thanks for your help.

 

[Duvie]

I'd say dont use the autmatic features...

p4 3.0ghz (3000) = 15 x 200fsb

when you oc to 10% that uis 10% of 200fsb for 220fsb x 15 = 3.3ghz...the extra is the crap Asus always pulls IMO...

I think itis clear at 10% your system is dropping the ddr ratio to 3:2....3/220 = 73x2 = 146 for 292ddr...

two things here...

a) set it manually to 5:4 ratio for 168mhzx2=366ddr or 1:1 if your ram can do 220x2 for 440ddr...

b) leave it at 3:2 and drop the cas timings cas 2,2,2,6.....

I would try to run 1:1 at worst cas timings and see if it boots. If it does then stability test it and if it is stable then start dropping the cas timings for better performance....

However do not be afraid to run 5:4 ratio if 1:1 cannot pan out at 440ddr or cannot run better then cas 3 timings...Many have tested (me included) and found cas timings often mean more the ddr speed and often the ddr speed does not mean the greatest in percentage increase in performance...

If 1:1 pans out at 220fsb but at lowest settings and not much more, though the cpu can maybe go to 3.4ghz...definitley go with the cpu speed increase cause in my testing raw speed makes a lot more of a difference except in 3dmark testing and some games...you should test it but I can tell you in multimedia, rendering, archiving, scientific, etc apps the cpu speed is far more effective.


Update: It is likely the automatic feature is SPD setting and it is reading your ram chip and when it is over its rated spec it is changing the multiplier....Not sure why it didn;t drop to 5:4 before 3:2 though...At 5% maybe you ram is still rated to run 1;1 or 420ddr but at a lower cas timing like cas 2.5....

My old PC3000 corsair ran 450ddr cas 2.5,7,3,3 w/ 2.7v and ran 420ddr still at cas 2.....


definitley try to do this manually...automatically is hosing you here...

 

[Degas]

Thanks for your reply. I now changed to the manual O/C and gone up to 227FSB, this had given me a memory bus speed of 151mhz(302Mhz DDR), I still need some advice on other settings though. Under the manual setup for O/Cing I have the following options:

CPU External Frequwncy:- Auto to 400mhz (Currently set at 227Mhz)

Dram Frequency:- Auto, 266,320,400 (Currently set to Auto, PC refused to start when I tried at 400Mhz)

AGP PCI Frequency:- Auto, 66/33, 72/36, 80/40 (Currently set to auto)

CPU VCore voltage:- Auto, 1.6 to 1.9 @ 0.25 increases (Currently set to Auto)

DDR Ref Voltage:- Auto, 2.55, 2.65, 2.75, 2.85 (Currently set to Auto)

AGP VDDQ Voltage:- 1.5, 1.6, 1.7, 1.8


Under the memory settings if I set to manual it is set a follows by standard:-

DRAM CAS# Lat:- 2.5
DRAM RAS# Precharge:- 4
DRAM RAS# to CAS# Delay:- 4
DRAM Precharge Delay:- 8
DRAM Burst Length:- 4

Again in Sandra my memory is posted as DDR-SDRAM 2.5-4-4-8CL 1CMD, which number 4's are which in Sandra.

Now I am not sure what the increase or decrease for best performance/stabilty for all of the above settings.

Many thanks again, I am a bit of a noob when it comes to o/cing.

 

[Duvie]

266 = 3:2

320= 5:4 (use this one)

400 = 1:1

hope that helps you...i will check back later

 

[Degas]

Seems to be stable at 320, although it's being reported running at 181mhz (362Mhz DDR) in Sandra, which is obviously better. So thanks for that. What about the other settings or my memory timing settings, should I have a play with them.

 

[Camofrog]

Originally posted by: Degas
Thanks for your reply. I now changed to the manual O/C and gone up to 227FSB, this had given me a memory bus speed of 151mhz(302Mhz DDR), I still need some advice on other settings though. Under the manual setup for O/Cing I have the following options:

CPU External Frequwncy:- 230

Dram Frequency:- 320 ( or 266 if your memory wont do the 320 at tight timings)

AGP PCI Frequency:- Auto

CPU VCore voltage:- Auto is ok with this board or set it at about 1.55 or something ( this board over volts a little)

DDR Ref Voltage:- Auto is ok but i have mine set at 2.8

AGP VDDQ Voltage:- 1.5


Under the memory settings if I set to manual it is set a follows by standard:- ( change them to; )

DRAM CAS# Lat:- 2
DRAM RAS# Precharge:- 2
DRAM RAS# to CAS# Delay:- 2
DRAM Precharge Delay:- 6
DRAM Burst Length:- 8

(those would be the best timings to set it at but i dont know if you memory will do it you will have to test)

Again in Sandra my memory is posted as DDR-SDRAM 2.5-4-4-8CL 1CMD, which number 4's are which in Sandra.

Now I am not sure what the increase or decrease for best performance/stabilty for all of the above settings.

Many thanks again, I am a bit of a noob when it comes to o/cing.

The Ratio's can be rather confusing but this is what i would reccomend you try; ^^^^ ( i modified your quote)
i will check back let me know
just understand when you set the 266-320-400 in BIOS that is not actually what they are running at those are just ratio's.
the memory speed will still be adjusted by your fsb
also if you got to a 3:2 ratio (266) with the tight timings you maybe able to get a higher fsb ( like maybe 250 is not entirely un real)
I also assume you are using stock cooling ?????

This is a good article if ya want to learn alittle more about your mobo toms hardware guide here[/quote]

 

[Degas]

Cheers all, I will have a play and report back.