E6750 Overclocking issue - P5B Deluxe

rushfan

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Mar 2, 2006
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Hi all,

I am attempting a mild overclocking of a friend's computer. He has purchased an E6750 and a new ASUS P5B Deluxe motherboard. I have been able to achieve an easy 3.2 GHz by bumping the FSB to 400 MHz but there has been an annoying price to pay for the increase. From a cold boot the system emits a beep code - one long and three shorts. The system will pause for three or four seconds, beep once more and then continue to POST and boot into Windows. The system is rock solid at that speed during routine torture testing. A warm boot of the computer does not cause the beep code - the system simply shuts down and restarts with the usual single beep which indicates a good POST.

A quick check of the beep code would seem to indicate a video problem, which really surprises me. There is no such error while the system is right-clocked so I doubt that there is an actual problem with the card (ATI X1650). The PCIe frequency is locked at 100 MHz and the PCI bus is locked at 33.3 MHz. He's using Corsair XMS2 PC6400 4-4-4-12 memory which I have loosened to 5-5-5-15 @ 800 MHz while troubleshooting. I turned off things like C1E, TM, Execute Bit Disable etc, but nothing has made a difference.

Any thoughts as to what might be causing this?

Thanks!
 

Mr Techguy

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When you overclock the front side bus you are effectivley overclocking everything that runs on that bus, including AGP, PCI, PCIe, USB, you name it. Modern motherboards may be able to combat this by seperating north bridge and south bridge bus. You are also overclocking the memory as well. That is why back in the hay day of PIII's changing the multipier was the way to go. That way you leave the system bus alone. Your problem may be related. You may be overclocking the PCIe also. It depends on if the board is smart enough to see it. The board I have allows you to unlink almost all of the bus's and overclock each individual component. Maybe you also have an option in the BIOS to unlink specific board bus's.
 

rushfan

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Hi,

Thanks for the help. If you re-read my original post you'll discover that I have indeed locked the PCIe and PCI busses at their proper speeds. I have also kept the memory at spec and even loosened its timing to eliminate that possibility.

I have been overclocking since 1996 but this one's got me stumped!

Thanks again.
 

CaptainScarlet

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Hi

Have you tried altering the Northbridge voltage and taking it off auto. I had a problem with the PCIe reverting to 1x if this is set too high
Mine works with it set to the lowest (1.25)

Also try taking the FSB to 401 - there are some strapping issues with this mobo that means the NB has to work really hard between 360-400ish - try a little higher - mine does 430+ no problems

Hope this helps

CS
 

rushfan

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Great tip - thanks! I left the NB voltage at "Auto" since I figured that this was such a mild overclock. I did however, avoid using 400 FSB. I tried both 399 and 401. As I mentioned, the system was rock solid at that FSB except for the damn beeping!

I'll give it another shot using this new information.

Thanks again.

-rushfan-
 

TheSaint2

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Hi,

Are you still facing this problem?

It's exactly the same problem I have here. I've changed my video card and still no go. One long and three short beeps at the cold boot ONLY.

When not overcloked, no beeps.

Do you have a solution?

TheSaint
 

rushfan

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This was a system that I built for a friend. I gave overclocking a shot but ultimately gave up on it and gave it to him stock. He was bummed because he spent extra to get what appeared to be, on paper, an excellent overclocking platform.

Maybe a BIOS upgrade will help? He was using the beta BIOS at the time that was the only one available that supported the E6750. Maybe a newer BIOS would help. Please let me know if and when you get around this issue.
 

midsilence

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Hello,

I'm getting the same problem here too.
I just upgrade my video card to HD 4850 and now I can't keep the overclock in 3.2Ghz. On cold boot I still have the beeps indicating video card problem, but in stock the POST is fine.

Have you find any solution?

Thanks!
 

midsilence

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It's working now!

After searching on internet I've found a solution.
My MB is a P5B-Plus Vista Edition and after changing the NB voltage to 1.4 and DRAM voltage to 2.1, I can run 4GB Corsair XMS2 in 4-4-4-12 and no post beep errors.

I hope it helps.

 
G

Guest

Guest
I used to get this all the time for months - sometimes my computer would boot normally and be fine then other times it would boot with 1 long beep and 3 short and then my sound would stutter when scrolling web pages, games would be unplayable, etc. Thought it was my graphics card at first but then I upped the northbridge voltage and it's been fine ever since.

Here's how I've got mine set up:
ASUS P5B Motherboard
Intel E6750 (overclocked to 3.2GHz, 1.35 vcore) - 20% overclock
4x1GB OCZ Platinum Revision 2 RAM (2.1 volts, 800MHz, 4-4-4-15) - no overclock
Geforce 8800GTX - no overclock

Northbridge is at 1.40v and I also set the PCI-E frequency to 100MHz and PCI bus to 33.33MHz. Everything else is left on auto and it's all 100% stable. Can also get my processor stable at 3.6GHz but I don't see the need to push it that far at the moment.


Hope this helps someone because this problem was a right pain in the ass for me for ages!