[chobbney]

Hello,

I'm new to overclocking and although I've read up on what to do, I don't really understand it 100% and I'm not able to get a stable system @ 4GHz.

The spec is:
Intel i7 920, D0
Noctua NH-U12P SE1366 CPU fan
Gigabyte GA-EX58-UD3R iX58 mobo
OCZ 6GB (3x2GB) DDR3 1600MHz/PC3-12800 Platinum Triple Channel Memory Kit CL7 1.65V (7-7-7-24)
Corsair 650W TX Series PSU - 120mm Fan, 80+% Efficiency, Single +12V Rail
Antec 900 Nine Hundred

I used this page as a guide and then pushed the BCLK up to 200 while increasing various voltages. I've tried to get my head round it, but I clearly don't understand enough. Here are the BIOS settings I changed:

Turbo = Disabled
Multi-threading = Disabled
CPU EIST = Disabled

BCLK Frequency = 200 (x20)
QPI Link Speed = x36
Uncore Frequency = x16
Memory Multiplier = 8
Performance Enhance = Standard

CPU Vcore = 1.35 (1.25 default)
QPI/VTT voltage = 1.335 (1.175 default)
IOH = 1.1 (kept as default)
DRAM voltage = 1.6 (1.5 default)

I ran Prime95 'Small FFTs' for 2 hours and it seemed fine, but running 'Blend' resulted in the PC freezing after about 40 minutes. (I also had some earlier BSODs while messing about with the voltages to get to the above settings.) The timings on the RAM from CPU-Z were:

DRAM Frequency = 800MHz
FSB DRAM = 2:8
CL = 10
tRCD = 11
tRP = 11
tRAS = 25
tRFC = 90
CR = 1t

I haven't changed any RAM timings manually.

The temps according to SpeedFan were all about 50 degrees when under full load.

Can anyone offer any advice on how to approach this? I won't be able to try anything until Monday, but hopefully I can understand more about how to acheive 4GHz.

Many thanks in advance.

p.s. I included the wrong RAM. Sorry about that - I've now corrected this.

 

[Juggalo23451]

i7 o/c guide(might help)
http://www.overclock.net/intel-cpus/...7-920-4-a.html

 

[Anirk]

Are you using OCZ platinums? I think they are rated at 7-7-7-24

From what I have been hearing when they are run at 7-7-7-24 they have problems and can cause crashes.

If you do set them at the rated speeds.

Otherwise set the cpu at 1.55 volts and see if that helps. If its stable drop it slowly till its unstable and set it up one notch.

Many times I start at the highest safe voltage and work down.

If unstable still set uncore at 12 and memory at 6 for now and see if that helps.

GL

 

[chobbney]

Sorry - I included the wrong RAM. Now fixed.

Thanks for the replies - especially the link to that guide. It's the clearest I've read yet.

Still working on this...

 

[chobbney]

Well it seems OK now. Thanks particularly to Juggalo23451 for that link, which explained it very well. I changed it to the following settings and it's run the Prime95 Blend test for the last 18 hours OK. Just running the small FFts now.

CPU Clock Ratio = 20x
- Turbo = Disabled
- Multi thread = Disabled
- C1E = Disabled
- EIST = Disabled
QPI Link Speed = x36
- Uncore = x16
- Isochronous = Enabled
BCLK = 200
PCE Express = 100Mhz
Perfomance Enhance = Standard
Memory Multiplier = 8
Load Line Calibration = Enabled
CPU Vcore = 1.4
QPI/VTT (Uncore) = 1.375
IOH Core = 1.2
DRAM = 1.66
- CPU PLL = 1.88
- ICH Core 1.2

It wasn't stable in Prime95 until I increased both the Vcore and QPI/VTT to their current levels.

Many thanks for the advice, people.

 

[ArmenianLegend]

for onething turbo mode should ALWAYS be on

 

[88EVGAFTW]

1.4V seems high for 4 ghz, try Intel Burn test, I've been finding that I can find out if the CPU is stable much quicker with IBT or OCCT3.0

 

[Blameless]

Some points to consider:

OCZ Platinum 1600 will probably not be 100% stable at stock settings. You either need to loosen timings, or bump the voltage. You should set the timings manually as well.

The 20x multiplier often requires vastly higher voltages for the same OC as the 19 or 21x (obtained by setting turbo and diabling all power saving features) multipliers.

 

[chobbney]

The RAM timings reported from CPU-Z are 10 11 11 25 (1T). Should I set these manually, then?

IntelSpeedBurn (10 runs) was fine. Temps went up to 68 degrees max. I tested at both 20x and 21x.

Would the Turbo mode not tax the system even more? I did notice in that guide that it should not be at 20, but logic seemed to say that 21 would be even more extreme...?

Anyway; I just Enabled the Turbo mode. POST still reported 4GHz (200 x20) but CPU-Z says it's 4.2GHz. I've dropped the Vcore from 1.4 to 1.35 and am currently running Prime95 to test. Intel Speed Burn was fine at 1.35 (temps maxed at 64 degrees).

 

[chobbney]

Well I left it running Prime95 'blend' overnight and the PC had powered down by this morning. I also had to try a few times to power it back on.

Prime95's Results file states:
Fatal Error:Rounding was 0.5, expected less than 0.4. Hardware failure detected, consult stress.txt file. (It had ran for about 6 hours.)

I'm thinking the Vcore of 1.35 may be too low so I've changed it back to 1.4. In case 4.2GHz is asking a bit much, I have also changed the BCLK to 191 (21x) to give 4.011GHz (I'm determined to get 4GHz, rather than just under). My current settings are:

CPU Clock Ratio = 21x
- Turbo = Enabled
- Multi thread = Disabled
- C1E = Disabled
- EIST = Disabled
QPI Link Speed = x36
- Uncore = x16
- Isochronous = Enabled
BCLK = 191
PCE Express = 100Mhz
Perfomance Enhance = Standard
Memory Multiplier = 8
Load Line Calibration = Enabled
CPU Vcore = 1.4
QPI/VTT (Uncore) = 1.375
IOH Core = 1.2
DRAM = 1.66
- CPU PLL = 1.88
- ICH Core 1.2
(Memory timings are Auto)

Intel Speed Burn was fine for 10 runs and I'm running 'blend' again now. So we'll see what happens...