prime95 errors with e8400 above 3.6ghz

[shotgunbill]

Hi there! I've spent the last day and a half searching for an answer but I can't come up with anything, so I've come back to the place that's saved my butt many a times.

 

Recently I've been getting back into the swing of messing around with my comp. Been out of the OC game for 4+ years, where I learned everything from these forums.

 

Anyway, I've got the following setup: e8400 C0, Asus p5ke wifi-ap, 2x1g HyperX pc6400, raidmax 650 PS. e8400 is running at a FSB of 420 with a vcore of 1.32 as listed by cpu-z. Memory is kingston hyperx pc6400 with stock timings (5-5-5-18) @ 1.1 volts.

 

I basically followed this guide: http://forums.overclockersclub.com/index.php?showtopic=71656

 

I'm getting the prime95 rounding error, usually within the first minute. I turn the fsb down to 400 and it ran fine for 5 hours, to where I stopped the test. I've hit a wall here, even if I got a dud e8400 I'd still have some room to go, especially since my idle temp is 35C and under full load its 53C at a very generous voltage.

 

ayudame!

 

Bill

[Danzer]

Hey Bill,

 

I'll try and help you out as much as I can. I'm kinda new to overclocking, but I've successfully OCed my e8500 to 4.0ghz with vcore at 1.35v in the bios. With cpuz, my vcore's at 1.31 at idle and around 1.29 at full load.

 

Pretty much all I did was that I raised my vcores everytime I got a blue screen and I finally managed to crank out 4.0ghz at 1.35 in bios. My temps at idle are 38c and 48c at full load. I didn't touch anything else. Try just changing the fsb and vcore only. See what happens.

[shotgunbill]

Thanks for the quick response,

 

At the moment, the only things I've changed are the fsb, vcore and the vdim (factory stated max 2.1). My system is running fine, it runs the everest stress test well and 3Dmark01 as well. It's just giving me a "FATAL ERROR - Rounding was .5, expecting less than .4" usually after less than a minute, sometimes up to 20. I'm not getting a BSOD or anything of the sort, it just stops stressing that one core and the other core keeps going. It's driving me nuts! I've thought about just not caring about prime95 and try other stress tests, but prime95 is the best and if there's an error it needs to be fixed.

 

bill

[Danzer]

No problem Bill.

 

You know what? The same thing has happened to me too. One of my cores stopped working and the other just kept going. I upped to vcore a little and both worked flawlessly. Try just changing the vcore and fsb. It worked for me.

[shotgunbill]

Wierd. I raised my vcore in my bios another notch and now it's showing a lower vcore in my cpuid, 1.304. Is that vdroop?

 

Anyways, I've got p95 running right now. It's at 11 minutes no errors yet!

 

bill

[Danzer]

To be honest, I don't know what vdroop is. That's how new I am to this. But I can say that the CPUz vcore is the right vcore. As far as I know, the vcore in CPUz is always lower than the bios.

 

Hope everything goes well in Prime95!

[shotgunbill]

Prime95 got the same rounding error on one core after 10 minutes. That was with a fsb of 430 which would put my clock speed @ 3870. I moved the voltage up another .0125 in bios when I changed the FSB to 430, which is shown by CPUID @ 1.312 volts.

 

It seems I'm hitting a wall at anything 420+ fsb.

 

Should I up the vcore even more? Or is it my ram that's having trouble keeping up. I've got my hyperx pc6400 running at stock timings of 5-5-5-18 @ 2.05 volts.

 

Thank you

[Danzer]

It could be your RAM. It can also be your mobo. If your mobo is not updated, that might be the problem. Also, is this your RAM? If so, one of the people on the reviews list said they changed their timing to 5-5-5-12 @ 1.96v and it worked for them. Maybe you should try that out. Who knows? It might work.

 

Good luck man

[mrinsk]

Hi there im new here but ill say this , if i were in your place id buy some good 1066mhz ram, that worked in my case and i got my e8400 from unstable 3.7 ghz to 4.0ghz prime stable But then it could also be ur mobo like Danzer said. On the other hand it could be something wrong with the chip, but i dont think that's the problem.

 

Cheers

[RJR]

OR, here's a CRAZY thought, maybe learn how to OC.

 

Maybe by lowering your cpu multiplier to take your cpu out of the equation and raising your FSB and testing to see if it is your Ram, maybe upping the NB voltage and setting the GTL ref voltages and doing more testing.

 

OH NO, that's just crazy and it takes too long to do all that testing and stuff.

 

I vote for just upping ALL the voltages, one of them has got to help.

[JBags]

since you're overclocking through the fsb (as you need to do with intel, unless you have an Extreme edition chip), when you alter the fsb, you alter the speed of the memory as well.

 

What does CPUZ report your memory speed as? remember, cpuz reports the base frequency of the memory, DDR doubles that.

so if it says, say, 400 mhz, it is running at it's rated 800 mhz Double Data Rate.

 

depending on what CPUZ reports, i recommend you go into your bios and change the memory divider to something that will bring you closest to pc2-6400 spec, 400 mhz (800 mhz DDR)

[RJR]

depending on what CPUZ reports, i recommend you go into your bios and change the memory divider to something that will bring you closest to pc2-6400 spec, 400 mhz (800 mhz DDR)

 

OH NO, central Jersey, I grew up in Kendal Park, still don't miss NJ.

 

He's running FSB at 420-430, the lowest his Ram CAN go is 840-860 at that FSB. Just FYI.