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Rather odd things

D

Deadeye

Weaksauce
Joined
Apr 24, 2008
Messages
124
Hello, overclocking newby here. :)
I've recently started overclocking my E8400 a bit.
Now, I'm experiencing some strange things. First of all, my temperatures. Core #0 is always 6 degrees Celsius lower than core #1. Is that a common thing? (Not always actually, it varies from 5 to 7 now and then, but 6 mostly.)

Now; number 2.
I've overclocked my E8400 to 3,6Ghz (using 400*9), having it run 1:1 with my ram. The Vcore is currently 1,275 in the bios. I could probably get it lower, but that's not important to me just yet. When I run Orthos, all the tests (3 and the custom one) except for StressCPU with the Gromac core give an almost instant error in one of the cores, stopping the stresstest and telling me to read stress.txt. (It's not actually there, but I've searched for that one and it's just some basic guidelines)
The thing is, the other Stress Test, the Gromac core one, is running several hours stable now, whereas the others would almost instantly give me an error. Also, SuperPi works without any lockups either. (1-32M, all of them.) Temperatures are also relatively normal, not the lowest because of my budget cooler (AC 7 pro), 45 and 51 degrees Celsius on load.
Could anyone tell me what could be causing this?

My system specs are in my sig, if there is anything else that you have to know (latency's, ram voltages etc) just ask me.

Thanks in advance, a junior overclocker.
 
#1 - I have a q9450, variance of 4*C at idle. If you think something is wrong, remount the heatsink with new goop.

#2 - Try prime95, loosen the ram timings. Underclock the chip to like 6x or as slow as you can go. Push the fsb to the limit, then up the multiplier, making small adjustments as needed.
 
i recommend running small fft's rather than stress w/Gromacs. it stresses the cpu more. if you're getting instant errors while running small fft's, increase your vcore to 1.3v and test again. if it passes at this voltage, you can try lowering it a notch and run the test again. if it fails, you will want to increase the vcore more. keep in mind that some e8400 require more voltage than others when OC'd.

also, to eliminate any instability issues with ram while OCing your cpu, unlink the ram from fsb. not all ram are created equal and some are real finicky with even slight OC. you can always tweak your ram speed after you get your cpu nice and stable.

keep the ram at stock speed and timings then test your cpu again. usually increasing the vcore will do the trick and stabilize your chip.

orthos is same as prime95. it's just prime95 with GUI. one or the other will suffice.

and please post your ram speed/voltages and the make. i'm just curious.
 
Hey. Thanks for those fast responses. Can't try to tweak anything tonight I'm afraid, it's 2 AM and I better get some sleep. Will try it the first thing in the morning though. :) Stress testing with the Gromac core also didn't work, blue screen after half an hour. Tried 1.285V, didn't work either. Put it back to basic values for the night. I was using my ram 1:1, so it was running at 800Mhz. Latencies are quite bad without loosening them already, 5-5-5-18 (Might have forgotten a five ;))
Running the ram at 1.8 volt, the recommended volts for the ram. Everything else is set as described in the overclocking guide at the top of this subforum, speedstep and all. I'm using an asus P5K so I'm afraid I can't run it unlinked, might be wrong though.
Thanks.
 
Right, I'm trying to get memtest86 on my USB stick, to see if my RAM is the problem. Not really working yet though. :cool:
 
Thanks, I'll try that one!
Ultimate Boot CD doesn't work for me though, I run windows XP x64. Wait, nevermind, I'll just get my laptop.
 
Yeah, didn't say it the right way ;) You need a 32 bit operating system to be able to make it run from your USB stick. The file that makes your usb stick ultimate boot cd doesn't work on x64 That's what I meant. I don't have a floppy drive and I currently don't have any CD's/DvD's either, could go buy them later on if this won't work.
 
Ah, got ya. There is an experimental usb stick deal there.. not sure what it involves.
 
Suppose I'll find out shortly :)
Still, the thing that bothers me the most is that my system can run on 100% load for hours (overclocked, that is), but when I try an orthos test, it fails after 1(!) second. Guess I've got a quite shitty chip, can't get 3.9Ghz stable with 1.385V (The last one before 1.4 on my motherboard, been told I shouldn't pass that one.)
I still think that it could be my ram. I have DDR2 800, so that means it has to be overclocked to reach anything past 3.6. The recommended voltage is 1.8V, should I try and put it up to 1.85, or would that do some serious damage? Also, something I didn't really get. Northbridge voltage, just put it on auto?
 
You should have bought ddr2-1066 at least. Your ram is probably holding you back. Download that windows memtest, I posted the link.
 
I don't know how your bios is but maybe you can unlink the ram, reduce the divider?
 
Hm, suppose it is. Someone here said that overclocking my ram to 890 wouldn't be a problem, don't blame him though. :) I can't run the ram unlinked as far as I know, could try changing the divider, although I don't think that will work either, I'm afraid. Can't know for sure though, will try that after your memory test is finished. :)

Well, after not that much of a struggle, I've got UBCD on my USB stick, working and all. Makes me a happy panda. I *discovered* something rather interesting while trying something with it. If I run Orthos from UBCD, it won't stop after 1-3 seconds. Ofcourse I haven't done hours of stability testing yet, but it's something.
 
Right, memory *seems* ok, will let it run whole night when I go to bed. Now, I was wondering the following. I've been told my Vcore should stay below 1.4V to reduce the possibility of damaging my CPU. This 1.4V, is this the 1.4 you tell it to be in your bios, or is it the 1.4V you see in your bios's real time monitor or programs like CPU Z? My bios has a tab called Hardware Monitor, which shows that my Vcore is 1.336, instead of the 1.385 I set. Does this mean I can set it over 1.4V and still remain in the *safe zone* ?
 
1.4v in cpuid (max) - The difference in voltage is called Vdroop. You are good.
 
Meh. Guess I had some bad luck with the chip. With CPU Z at 1.392V 4Ghz still ain't stable. Should do some more testing though, who knows 3.9 will be stable at a decent voltage. Doesn't really matter anyway, not like I'm going to notice the difference.
Thanks for your help so far :)
 
try upping your vmem to 2.0v. most ddr2 800 can safely go up to 2.1 - 2.2 so you should be fine. also what are rest of your system's voltages? NB (MCH) especially.

keeping the divider at 1:1 should be fine since you're not going above 3.6ghz.
 
erm, let me rephrase that...
since you're going up to 4ghz, what is your mem speed currently at and what divider are you using?
 
Sorry, let me rephrase as well in that case :p
I'm still using a 1:1 divider, can't manually set my ram I'm afraid, no manually adjustable divider either. Just a dropdown list, with the lowest value being the 1:1 value. Timings are 5:5:5:15, tried it with 6:6:6:18 too. Northbridge is auto, Vcore, well I've tried everything up to 1.415V, Ram is 1.8.
 
Deadeye said:
Sorry, let me rephrase as well in that case :p
I'm still using a 1:1 divider, can't manually set my ram I'm afraid, no manually adjustable divider either. Just a dropdown list, with the lowest value being the 1:1 value. Timings are 5:5:5:15, tried it with 6:6:6:18 too. Northbridge is auto, Vcore, well I've tried everything up to 1.415V, Ram is 1.8.
Click to expand...

1:1 is the highest value - for instance 4/5 = 80%

oops - sorry guess that's wrong in your case. Like I said - I don't know your bios.
 
1:1 is not the highest value. it is usually the lowest setting as any other divider setting usually increases the ram speed more than the fsb.
 
Yeah, exactly. 1:1 is the lowest my motherboard will go. Everything else will just increase the ram further. Would there be anything you could suggest, like changing the NB voltage, or the ram voltage for that matter? Also heard something about setting CPU PLL Voltage to 1.5, is that going to help me? I don't know anything about these settings, I'm afraid. They weren't covered in the guide at the top, and that is about as far as my knowledge currently goes. :(

I still think my CPU is the problem though. The error is very easy to simulate. Normally, I run 333*9 @ 1.125V in the bios and 1.088V in CPU Z (Idle). If I use SetFSB (or the bios, which I normally use) and change it from 333 to 340, you already get the same error in Orthos (or Prime, doesn't matter.), something like rounding is 0.5 where it is expected to be 0.4 or less. That is the exact same problem I get when overclocking further.

Also, for the record, my VID is 1.2250. That isn't very lucky, is it?
Edit: A bit strange, but right now I'm having 33 33 idle temperatures, instead of the highly different ones I posted about in the start. Didn't change anything though, weird.
 
do you have another set of ram that you can use? you can also try it out with only 1 stick of ram as well. many times, it's not the cpu that's faulty but the ram. having a faulty ram will give you errors just like the ones you're currently seeing in orthos.

it can be the cpu but i wouldn't make that assumption until i tested it out with a different set of ram.

btw, my e8400 vid is same as yours. temp sensors on the e8400 are not the most reliable either.
 
Well no, I'm afraid I don't. Going to bed now though, I'll let memtest86+ run all night. But if it would be ram, wouldn't that mean that I should always be getting this error? Because I don't when I'm not overclocking my CPU. It can't be only when I overclock my RAM either, because when I raise the CPU without raising the RAM, I also get the error. (e.g. when setting it from 333 to 340, ram's not overclocked and I still get the error)
Anyways, the voltage in your signature, is that the one measured in CPU Z, or the one you put in in the bios? If it's the CPU Z one, could you tell me what your value in the Bios is?
Anyways, see you guys in an hour or 8. :cool:
 
it is the cpu-z voltage reading. in bios i have it set at 1.38125, i believe (not currently at my comp but it's right around 1.381). slight vdroop but not as bad as it used to be due to the vdroop mod i performed on the board.

if your mem passes memtest without any issues, try running your fsb at 400 at 1.36 - 1.38v and as much as 1.4v. due to the vdroop you're seeing, you may need to set the vcore a bit higher to compensate for it. also you chip may require more vcore than your avg e8400.

with 1:1 divider, your ram will be running at 800mhz which is stock speed. keep your timings loose at 5-5-5-15, everything else on auto and apply 2.0v at first and if not stable at this speed, go up to 2.1v. not sure what voltage your ram is rated at but most can handle up to 2.2 - 2.3 without issues. having a fan definitely helps once you start exceeding 2.0v though. i currently use a shiny led OCZ ram fan.

cpu pll, i believe, helps to stabilize fsb speed. try setting that to 1.5v as others have suggested.
your NB voltage should not need any voltage increase since you are not OC'ing the ram but since it can and does sometimes help to stabilize OC, you can try to manually set that higher about .2v than what is currently set at on auto. does your board show what the NB voltage is set at when it is on auto? you can also use everest ultimate to display various motherboard voltage readings i believe... not sure if it will show NB voltage though.

try to move your ram out of the current slots and move it them over to the two others slots and test again. also take into consideration that your board "might" not like to be OC'd with 2x2gb of ram.

it may be your cpu but whenever i've had OC problems, it was always the ram or incorrect voltage settings. at first, i used to think that it was always the cpu but it always turned out to be the ram.

went through 3 different sets of ram to finally find the set that is OC "friendly" with my board and cpu. first was corsair dominator ddr2 800. did not like to pushed at all. second was 1066 ocz platinums. not bad but garbage ecc settings that required insane amount of initial voltage or it refused to boot.

finally settle on plain ol looking super talent ddr2 800's which are incredible OC'ers.
 
Thanks, I'll go and try those things. Might get myself one of those corsair dominator coolers, if they fit anyway. My RAM doesn't even have a heatspreader...
Memtest86+ ran 13 hours without errors, 20 passes. Sounds good enough. :) My ram is rated at 1.8V, crappy kingston ram I suppose. Don't have the wide range of products newegg has here in the Netherlands.
I think it's not the CPU really, just that it needs more voltage than others, like you said. I got 400*9 stable at 1,385 in bios, I'll try to see how much lower I can go. The vDroop mod you spoke about, is that recommended? I've read quite a few posts of people that made mods like that. Don't really know if it's going to help me though.
 
Alright, got Everest up and running. Voltages as we speak are:
Northbridge: Intel Bearlake P35; 1.25V
South Bridge: Intel 82801IB ICH9; 1.05 V
The ram: 1.8V (Manually done that, as recommended on the site
CPU PLL: 1.5V
Suppose that's all, right?
 
vdroop mod is not very hard to do but you do have to be careful. you don't want to "draw" to many lines though as it will significantly increase the vcore, even at idle, and it will increase the vcore even more during load. it can be very dangerous not only to your cpu but to other components on your board.

so 400x9 @ 1.385v is stable and you have about .03-04v vdrop. but do you actually have vdroop? my mobo had severe vdroop of .04v during idle to load. after performing the mod, it stays pretty even now and i don't notice any decrease at all. does your vcore voltage change dramatically from idle to load? if so, you may want to perform a vdroop mod, which will allow you to set your initial vcore lower. also, your mobo may have an option to reduce this vdroop in bios. you may want to check that out.

as far as i know, you can safely increase your mobo's NB voltage to 1.4v. if you want to OC your ram, you may want to raise the NB voltage just a bit. if you're satisfied at running 1:1 at 800mhz, then you can try to tighten up your timings, which is basically another means of OC'ing your ram. This will require a bit of voltage increase. you will not reap any benefit from OC'ing your ram beyond 800mhz unless you go way beyond 1000mhz+ range. it is better to keep it at 1:1 and tighten the timings unless you can sucessfully OC your ram at much higher mhz.

btw, everest is one of the best programs out there. provides you tons of info about practically everything on your board.
 
Well, my Vdroop from Idle to Load is 0.032V. My Vdroop from the Bios to CPU-Z (If that's also called Vdroop) is 0,021V. So that's 0.053V less from the bios setting to load. This is all at 3Ghz though, should try and see if it's the same at higher FSB numbers.
I'll try to mess around with the timings. Will I actually notice any difference when I tighten them?
And yeah, Everest sure does give you a lot of information, I don't understand half of it, lol :p
 
usually you will not see much difference when you OC your ram. the benefit is perhaps 1-3% increase in performace which is not noticeable unless you're running benchmarking programs. but i still prefer to push it anyway because it's just fun to do so, lol.

everest has a nice nifty little tool that can test your memory bandwidth and latency. it's one of the options under tools. can't remember exactly what it is called.

vdrop is the initial drop in voltage that you see in cpu-z compared to bios. vdroop happens during idle to load. .032 vdroop is not bad, not great either, but if you perform the mod, you can set your initial vcore lower. like i stated earlier, some P35 mobos have the option to reduce this vdroop in bios. can you post all the voltage names in bios?
 
Hah, thanks for asking me that list of voltages! I actually just updated my bios to the latest (not sure if it is the greatest though) and some new options came with it. One of them is called Load-Line Calibration, which is said to reduce Vdroop. It did, a bit anyway. My Vdroop now is 0.024V, still only a 0.008 increase anyway, not that spectacular.. Might be better at higher voltages though. I'll give you that list:
CPU Voltage
CPU PLL Voltage
FSB Termination Voltage
DRAM Voltage
NB Voltage
Clock over - charging voltage
Load-line calibration
CPU GTL Voltage Reference (Can't really find out what this does, tried searching some forums but it remains vague, something to help increase the max FSB? Could this one help me?)
NB GTL Voltage Reference
CPU Spread Spectrum (Even more vague than CPU GTL Voltage, don't get this one at all.(
PCIE Spread Spectrum

Right, now I'm at it, I'll list the other options aswell.
AI Overclock tuner
CPU Ratio Setting
FSB Strap to NB
FSB Frequency
PCIE Frequency
DRAM Frequency
DRAM Commandrate
DRAM Timing Control
DRAM Statis Read Control
Transaction Booster
I just found out that I don't know what halve of these actually do. Shame on me. Time for some RTFM and Googeling.
 
it is normally advised to turn off any spread spectrum options. not too familiar with it myself but something to do with reducing electro magnetic emissions that may interfere with other electronics. usually not required in home use and it is advised to be turned off especially when you are OC'ing.

CPU GTL Voltage Reference - no clue to what that is either.

yeah, google is definitely your best friend in your situation. your mobo definitely has quite bit more options in bios compared to mine.

keep in mind that to obtain a good stable cpu OC, more often than not you have to tweak and adjust various other voltages and settings in your mobo's bios.

usually, good source of info regarding your mobo and various different bios settings can be found in the manufacturer's forums.
 
Did some googeling, found most of them. Funny thing is, Load Line Calibration doesn't work. At all. I get the same result at disabled and at enabled. Hooray.
 
Right.. When using 1.35V in the bios for 400*9, I get a Vdrop that constantly changes, it goes from 1.312V (Most of the time) to 1.304V to even 1.296V. After that, I get a Vdroop to either 1.264V or 1.256V, also constantly changing. That is a total loss of almost 0.1V, from bios to load, could that have something to do with my high instability?
 
Thanks, that was an interesting read. The thing is, I would really like my CPU to reach 4Ghz stable. But I'm afraid to go over 1.4V in the bios, because of the things people say about burning your CPU and stuff. The combination of Vdroop and my chip not being a very good OCing chip makes this rather hard. It makes me think that reducing the Vdroop could help reaching stability, since the error's occur under load, not under idle circumstances. That would suggest the Vdroop taking away too much voltage, making it unstable. I could be totally wrong ofcourse, since I'm not an expert at all.
 
set in bios 1.35v but get only 1.256v at load? yeah that's pretty severe. so at 400x9, your chip most likely needs about 1.3v but is getting far less than that. this equates to failures during stress tests because the chip is not getting the voltage it needs.

one thing you can do to find out if vdroop is the cause of your current instability issues is to perform the vdroop mod. this mod is completely reversable if you feel that you are not 100% comfortable with theoretical dangers associated with removing vdroop.

what i can tell you is that there are plenty of people who have perform the mod and seen successful results without any negative side effects, including myself.

again, if this mod does nothing and you are still having stability issues, you can completely undo the mod by using a simple pencil eraser. if you do decide to perform it, make sure you find a good guide(s) and do take your time. improper vdroop mod can be extremely dangerous.
 
Thanks a lot, I'll sure be trying that tomorrow. Only problem is that my motherboard isn't popular at all, almost no one has it. Googeling for Asus p5k vdroop mod gives no results at a first glimpse.
 
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