VCORE QUESTION

[bakaman 28]

Hi fellas,I have a p8p67 i5 2500k rig and i just boosted it to 4,8ghz (i was at 4,6). i have set the cpu voltage on manual to 1,3v and the system seems to be stable at 1,3v for 4,8ghz. But the thing is that now my vcore is constant all the time : at idle and full load at 1,29 1,3. The question is: is this a good thing?Kaman BA

[dazz 69]

1.3V for 4.8GHz is most likely not enough. You should stress test with Prime95, OCCT, Lynx... to make sure it's stable, temps are fine and to check your real full load Vcore in CPU-Z. That's what matters and not what you set in BIOSWhere's your Load Line Calibration at? Without LLC you'll have Vdroop, meaning that as you increase the load, Vcore will get lower and may cause instability (just in case you didn't know)You can have your CPU throttle back to 1.6GHz and around 1V while idling by activating SpeedStep (EIST) for frequency, and C1E for Vcore, but you'll need to set your Vcore using "offset" mode instead of manual or it will stay at whatever manual Vcore you set it to. If you set your Vcore in offset mode, don't type in 1.3V. It works adding or substracting an offset to a base value that depends on your actual clock and LLC level, so you'll need to play with it to figure out what offset you need to get the right Vcore for your particular setup. For example I use Extreme LLC and at 4.8GHz HT off, I need an offset of -0.060V for a full load 1.35V. Increasing LLC increases the base Vcore, as does increasing the CPU multiplier , meaning that you'll need less offset for a certain target Vcore Some say it's better to set it manual, but I don't see the benefits when I test both configs and always use offset + C1E + EIST.

[bakaman 28]

My system is stable, at 4.8ghz with 1'3v and runs fsx during a long time very nicely plus when going under 1,3v the pc doesnt boot up (blue screen). So i guess as far as i can maintain such a low voltage, i'm doin fine right?Kaman BA

[mikea76 184]

Watching this thread. I am just getting into OC and have done it a little with my current setup, the rest of the parts for my 2500k rig will be here in a few days so I am going to watch this and see what I need to do to get 4.8 or so out of it.

[dazz 69]

My system is stable, at 4.8ghz with 1'3v and runs fsx during a long time very nicely plus when going under 1,3v the pc doesnt boot up (blue screen). So i guess as far as i can maintain such a low voltage, i'm doin fine right?Kaman BA

Well, no, you're not doing fine, LOL :biggrin:Again, you should stress test and 1.3 is your full load VCore as shown in CPU-Z or what you set in BIOS? what LLC?

[bakaman 28]

Well, no, you're not doing fine, LOL :biggrin:Again, you should stress test and 1.3 is your full load VCore as shown in CPU-Z or what you set in BIOS? what LLC?

I have cpu voltage 1,3vLLC extreme 48 *100 mhz

[Sawydz 4]

Well, no, you're not doing fine, LOL :biggrin:Again, you should stress test and 1.3 is your full load VCore as shown in CPU-Z or what you set in BIOS? what LLC?

Well, if he can get from KLAX to EGLL without BSOD than we can say he is stable on that 1.3V

[antic81 57]

I have cpu voltage 1,3vLLC extreme 48 *100 mhz

Did you notice anything in terms of performance going from 4.6 to 4.8? The machine I am getting is coming already OC'd to 4.6 and not sure I'd notice the difference?

[bakaman 28]

Well, if he can get from KLAX to EGLL without BSOD than we can say he is stable on that 1.3V

that's also what i think but can someone else confirm this?by the way whats bsodKaman BA

Did you notice anything in terms of performance going from 4.6 to 4.8? The machine I am getting is coming already OC'd to 4.6 and not sure I'd notice the difference?

honestly its too early to report about it but at 4.6 i have a video for you just watch my previous post.

[dazz 69]

A basic guide to overclock Sandy Bridge:You'll need:A "K" version Sandy Bridge CPU coupled with a P67 or Z68 board (preferrably with full VRM support) and a proper aftermarket heat sink fan or WC loop to cool your CPU downDo not:Overclock using any auto-tune option in your motherboardOverclock using any kind of windows based tool. Always set everything manually in BIOS and double check your inputs are correct / within specs in windows ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------1.- Test the system at stock settings for a reasonable period of time (at least one week). Download all the necessary tools:- CPU-Z 1.57 to monitor Vcore, CPU and memory speed and timings- Speedfan 4.44 and/or HWMonitor to contrast with CPU-Z and make sure you have correct readings - CoreTemp to monitor temperatures (and RealTemp)- Prime95, Lynx, OCCT to stress test- Memtest (latest version, compatible with SB)Stress test on stock settings and make sure your max temps are fine (50 - 60ºC or so, depends on your cooler and ambient temps)Run a couple of runs of Memtest to ensure your RAM is fine 2.- Keep your memory at default speed and timings and start with manual Vcore and LLC at High, Ultra High or Extreme to limit or cancel Vdroop. Disable EIST and C1E (so you can see your actual cloks and Vcore even when idle)Try a moderate OC first. Something like 1.3V and 4.3 - 4.4GHz. If you want to go for a higher OC straight away, don't exceed 1.37 - 1.38VBoot into windows and open CPU-Z and CoreTemp. Make sure your CPU clock is where you set it to, temps are in check and Vcore is ok too (max 1.37 - 1.38V, but with LLC on and C1E disabled it should be pretty close to what you set in BIOS)If CPU frequency, temps and Vcore are fine, stress test with Prime95 or OCCT for half an hour more or less. Keep a close look at your core temps and CPU-Z for Vcore: that's the Vcore that matters, the one you get at full load. If it's significantly lower than your idle Vcore, raise your LLCIf it passes the test, you can try lowering your Vcore or raising your clocks. Repeat until you get your desired clocks or maximum safe full load Vcore.Once you are done, fine tune your overclock stress testing for 8+ hours. If it fails raise your Vcore one notch, of course without exceeding 1.37 - 1.38V at full load, and repeat until you pass at least 8+hours. Monitor temps and VcoreYou know now what Vcore you need for your OC. 3.- Obtaining the offset value to get the Vcore at which your OC was stable in the previous step (in manual mode)this are the approximate values for each LLC level. I believe this table was made at 4.6GHz. Not sure thoughSo for example, if you want 1.35V and your LLC is set to Ultra High, set your offset to -0.010.Boot into windows and open CPU-Z. Stress test for a minute to see what full load Vcore you have and see if your Vcore is where you want it to. Lower? raise it in BIOS and try again. Higher? lower it in BIOS.Once you have your offset, you can enable C1E and EIST. Check if it throttles down to 1.6GHz and 0.9 - 1V while idle, and stress test again for 8+hours. Monitor temps and Vcore while you do4.- You have (hopefully) a rock solid CPU overclock now, time to focus on memory speed. Set your RAM speed, timings and voltage at what your sticks are rated and stress test for 8+hours. Monitor temps and Vcore while you doIf you want to overclock your memory, do so, and stress test for 8+hours. Monitor temps and Vcore while you doSB is not so picky with memory as previous generations were, so you could try setting your RAM at it's rated speed, timing and voltage from the beginning and skip this step, but I still prefer the old school wayNOTE: maximum core temp, 80ºC under full load. Maximum Vcore 1.375V at full load

[Sawydz 4]

BSOD stands for Blue Screen of Death, very common view when OCing CPU ;) And about stability, in my case I can stress CPU in LynX for few hours flawlessly but FSX will verify that in one hour.

[bakaman 28]

i just gave a try i got no error but temp was stable at 75c when using prime 95. but when testing on fsx temps are around 55 60c no more than that.

[dazz 69]

i just gave a try i got no error but temp was stable at 75c when using prime 95. but when testing on fsx temps are around 55 60c no more than that.

How long did you run Prime95? and What Vcore at full load in CPU_Z Kaman please? Did you set your RAM to it's rated speed and timings?Are you OCing in BIOS or using a Windows tool?

[bakaman 28]

How long did you run Prime95? and What Vcore at full load in CPU_Z Kaman please? Did you set your RAM to it's rated speed and timings?Are you OCing in BIOS or using a Windows tool?

i ran it for 10 min but i know its not enough, tomorrow i'll stress it for several hours. i get vcore 1,312 at full load. ram at normal speed. OCing from bios. thank you

[dazz 69]

i ran it for 10 min but i know its not enough, tomorrow i'll stress it for several hours. i get vcore 1,312 at full load. ram at normal speed. OCing from bios. thank you

Ok, looks good. If you can get it stable at 4.8GHz and such a low Vcore, that's a true golden nugget of a CPU you got there!