Suspected fsb wall on p45.

[Gravitational24]

Hey I have an e8400 and asus p5q pro mobo with gskill 1000mhz ddr2. My system is currently overclocked to just over 3.8 ghz and is working great. I would really like to get to 4ghz though. Up until now my system has needed very little extra voltage to attain that speed. But as soon as I attempt to get up past 435-445 fsb i encounter problems. The cpu is fine it will do 13 hours of prime 95 small fft and only reaches temps of 49 to 50 degrees at 4ghz. But as soon as i load something that involves graphics it freezes up. It will do this with supreme commander but if i play crysis and run prime 95 blend in the background it does it as well. It has never BSOD on me. It freezes 95% of the time and has crashed a couple of times. the memory is running below spec so it's not that. So I am thinking I have hit a fsb wall.

Here are my system settings.
V core at 1.3 (At 3.8ghz it can run stable below this but i leave it at this to make sure the cpu doesn't crash the system. At 4ghz It would still crash with the vcore at 1.4 volts.)
Vtt 1.38
Northbridge 1.5 ( I have an 80mm fan Strapped to this)
Pll 1.5 ( Default volts. I haven't touched this because I have heard its very easy to fry your cpu)
Southbridge 1.4 ( Max voltage available)

My fsb strap is set to 400. My understanding is this will allow the highest fsb overclock?? Is that correct?

What about trd would that affect it?

Cpu spread spectrum, pcie spread spectrum, eist are all disabled.

I have heard of this board getting to 500mhz and apparently a fsb strap of 333mhz generally walls at 500mhz so i was hoping for a bit more.

If anybody has any ideas that would be great.

 

[hundredislandsboy]

Try 8 multi at 500 fsb. Disable C1E, EIST. 1.38 vcore should be enough. FSB strap to 400. Let me know how it goes.

 

[Gravitational24]

Ok so i upped the fsb to 500 and multi to 8. It froze up as soon as i started it. I got a black screen from the beggining so i lowered it by ten and the same thing happened. When i got to about 470 it booted into windows.

Strangely enough CPUz was reporting a fsb speed of 470 but si software sandra reported a speed of over 500mhz???? Doesn't this have something to do with your fsb strap and default multi divided by current multi?? Can someone shed some light on this???

Any way it was unstable so i upped northbridge and pll volts a bit.
NB at 1.58 (One setting below where the mobo says Warning extra cooling needed)
Pll 1.58

I set the multi back to 9 and booted into windows with an fsb speed of 460.

I ran prime 95 for about an hour and no problems so I loaded a game but after about 30 seconds it froze again.

I'm just not sure where the problem is and what to do about it. Thanks for the help.

 

[hundredislandsboy]

A little surprised you're not already at 8 X 500.
Your RAM or RAM settings are probably causing the instability. Is it 1066 and what timings? If your ram is rated 800 mhz, unless it's rated for high performance and you've loosened them to 6-6-6-18 timings, it still may not work.
Se we know, your motherboard can go to 470 but not sure about 500 (yet).
At any rate, my e8400 can run all day at 8 X 500 or 9 X 450 but that's it, one more tweak just to squeeze out 1 more mhz always fails.

 

[Gravitational24]

The ram is officially rated for 1000mhz at 5-5-5-15 at 2.1v. Thats its epp setting. At 1.8v its only rated at 800mhz but I have had it at 2.1v right from the begging. I will try loosening the timings a bit and see what happens.

Yeah I can get it to 430 mhz with hardly and voltage changes at all. But at 445mhz my system would crash with vcore at 1.4 and nb at 1.55.

I briefly tried the nb at 1.64v this evening and it still crashed.

 

[sprucebr1]

I bet you know, but I thought the FSB wall on P45 was 1600Mhz? Quad pumped thats 400Mhz FSB. I bet a few boards can get to 450Mhz - 500Mhz. DDR2 800Mhz should work in this case. Otherwise I would just switch to DDR3, lol.

 

[Gravitational24]

Well yeah it's officially rated for 1600mhz=400fsb but I was hoping for a little more. If not i'm happy with what Iv'e got. So here's hoping lol.

 

[Pointertovoid]

Could the Pci-E frequency be too high?