Vcore/mem ratio/fsb

[aaroncat]

Hey

Specs:
Asus P4S533 2.4
768 DDR ram
Zalman HS and cpu fan
Enermax PSU
11 fans=very good case cooling

Question:
I have been taking my fsb up at certain increments and testing the stability of my system with prime95.
Now I have had my cpu speed at 2.93 and the system seems completely stable but it will not last 2 minutes of the prime95 torture test.
At 2.88GHz it will last about 4 hours and then halt due to hardware error.
I haven't messed around with the mem ratio or vcore to much. How do I know when I have to take my vcore up or change my mem ratio???? What are signs of instability that will tell me I need to do either of these things???
My temps are very good idling between 19° at 2.4GHz with 1.5V
and 25° at 2.93 with 1.575V

 

[aaroncat]

oh yeh the error in prime95 is as follows (if this is any indication of what the problem might be)



FATAL ERROR: Rounding was 0.498046875, expected less than 0.4
Hardware failure detected, consult stress.txt file.

 

[Baowuf]

Sounds like your cpu could use more juice. Try taking it up the smallest amount possible and re-run prime95. Prime95 errors are usually, but not always, are signs of cpu instability. eg, change the mhz/multi/voltage. BSOD's can be signs that your memory needs tweaking. However, you can get any error with any combo of settings, so just take it slow.
Good luck.

 

[Leviathan41]

Yeah you should be able to juice up the voltage as much as you need with that much cooling. 11 fans, hehe.

 

[aaroncat]

What do you guys think are bad idle and load temps to where I should be backing off voltage???

 

[larva]

The SiS 645DX chipset that the P4S533 carries gets unstable about 95 times out of 100 when the fsb is raised past 150MHz. It may not be your ram or cpu's fault.

The chipset does offer a wide range of memory ratios, select 1:1 for testing to ease the load on the memory. You can increase the memory voltage to 2.7 or 2.9V by moving the jumper for that purpose on the board, the control for this is not in the bios on this board. But at 1:1 you shouldn't need additional voltage, so if it is still unstable at 1:1 don't worry with additional memory voltage. If going to 1:1 does help, try raising the Vdimm some to see if you can run the 4:5 or 4:6 ratios.

Set your Vcore to 1.65V, this is a safe level and most 533fsb P4's need at least this much for an optimal overclock. But obviously if it's just the chipset giving up more Vcore won't help. If 1.65V doesn't clear up your prime trouble I would return the Vcore to the stock value to save wear and tear on the cpu.