My Intel I7 920 D0 @ 4.2 Ghz with HT on and off ...

[bhavv]

Is this supposed to be normal ...

HT off, 1.4v in Bios:



HT on, 1.45v in Bios (huge fail):



Its on my GA X58  UD5, also, how come voltages in CPUZ are so much lower then what I set in my Bios? I think that might be a reason for why I am needing to set the bios volts so high?

[bhavv]

I got up to 4.0 Ghz with HT on and ok temps, I have some Arctic MX3 ordered to replace my current Asus paste which should help to reduce the temps by a few degrees. I also managed to get my ram stable at 1600 Mhz 7-7-7-20 - I updated to the latest mobo bios which added better ram compatibility in one of the updates and increased the channel reference voltage a little.



My bios settings are - CPU Voltage 1.4, QPI is 1.335, CPU PLL is 1.86, and ram is 1.64.

Hyper threading really hurts overclocking and temperatures . The ram is Geil Ultra Series PC3-17000, rated for 2133 Mhz @ Cas 9, but it is more stable at 1600 Mhz Cas 7, or 1800 Mhz Cas 8, and wont boot at 2000 Mhz Cas 9. I am sure that this is due to having 6 modules in triple channel, the ram itself is fine and was on a great offer for OEM unboxed sticks

[Elemental_Dragon]

Voltage is WAAAAAAAAAAAY too high

i7 920 @ 4.2Ghz HT on @ 1.3v - even that is actually too high for mine but new board and the v-droop is killer - drops to 1.2v

QPI needed 1.38v but again - killer v-droop - BUT - I'm running 6GB DDR3 2000mhz CAS 10

My old board could hit BCLK 223 with only 1.32 QPI. Needs more IF you all RAM channels filled.

Seriously - reduce your CPU V-core and watch your temps drop. I let it on auto to test my RAM and it showed 1.36 in CPUz before v-droop kicked in under load and set it to 1.3v in BIOS and I dropped nearly 15c - and that's with Maplin's £1.50 value thermal grease!

~Bex

[bhavv]

It is unstable at lower volts. It needs 1.4 in bios for 4.2 Ghz without HT, 1.45 for 4.2 with HT, but the reason why this is is because the volts are being dropped in windows.

I added some MX3 and the temps have reduced by a few degrees, will post a screenie when I stress it for a while.

I have read that up to 1.4v and 85 degrees is fine for this chip. I dont understand why my voltages are running so much lower in CPU-Z! When I set 1.3v in bios, CPUZ says it is only 1.26 and anything over 3800 Mhz blue screens without being pushed up to 1.4v.

[absic]

I wouldn't get too hung up about the voltages. If the system is stable and the temps are acceptable there isn't really a problem.

No two rigs will run exactly the same even if they are built with identical components, that is one of the things that makes tweaking and overclocking so much fun. You can get a rough idea of some basic settings, from what other people are achieving but that's all it really is a rough idea and a starting point on your own journey.

[bhavv]

From plenty of reading, I have found out that up to 1.4v core, 1.35v QPI, 1.65v ram, and <85 degrees is fine for the I7.

I replaced my Asus thermal paste with Arctic MX3 today, and added an extra fan over my 5770s using a Zalman fan bridge, and this happened:

[bhavv]

Can anyone tell me wqhy my voltages are being reduced so much while the CPU is under oad, and how to stop this from happening? I need to set 1.475v in the Bios just to get 1.396v while Prime 95 is unning. I have disabled all the power saving and auto clock / voltage settings but it still happens.

[oggmonster]

Can anyone tell me wqhy my voltages are being reduced so much while the CPU is under oad, and how to stop this from happening? I need to set 1.475v in the Bios just to get 1.396v while Prime 95 is unning. I have disabled all the power saving and auto clock / voltage settings but it still happens.

Its meant to do that, when you set the voltage in BIOS then you load up windows + CPU-Z you will see the voltage lower than the BIOS. This is called vdrop. Then when you run the CPU at full load the voltage will drop again - this is called vdroop (think I got them the right way round!? ) This is normal and is actually part of the intel specification.

There should be an option called Load-Line Calibration in the BIOS. This will help with the vdroop 

[bhavv]

So it is ok to leave the bios voltages set higher then?

[oggmonster]

Yeah, loadline will help your vdroop if you want to give it a try and can sometimes help with general stability issues. My E8600 @ 4.53ghz was set 1.43750 in BIOS, but when running full load with prime95 CPU-Z reported it at 1.408v

[bhavv]

Eureka!!!!

Enabling LLC made my overclock stable at lower volts. It is set to 1.4v in the bios, and reduces to 1.36v in CPUZ under load, and no BSOD for 10 mins of Prime

All I had to do all this time was enable LLC, but I had no idea what it was. Having it disabled on Intel Spec is what was causing my instability over 3800 Mhz.

[oggmonster]

Eureka!!!!

Enabling LLC made my overclock stable at lower volts. It is set to 1.4v in the bios, and reduces to 1.36v in CPUZ under load, and no BSOD for 10 mins of Prime

All I had to do all this time was enable LLC, but I had no idea what it was. Having it disabled on Intel Spec is what was causing my instability over 3800 Mhz.

SWEET! Nice one mate, you will probably want around 8hours prime stable. Though whats "stable" is down to personal opinion. Some people only look for 1 - 2 hours prime stable.
Though you're getting there. Keep trying 

[bhavv]

Well, it blue screened so I'm back to 1.396v

[oggmonster]

Keep going, try small voltage increases. Just be careful not to go over the reccomended voltage (if you're worried about longevitiy that is)

[bhavv]

1.396 is completely fine, i were running prime for the last two days to test and I have no problems.

My I7 needs just under 1.4v for a stable 4.2 Ghz, but I have enough cooling to handle it, and its not exactly ever going to reach 100% load in any other program.