Help me hit 4.2 GHz Stable 24/7

[homefry]

I'm running G42 bios. Here are the settings below. I'm running all stock volts except for VTT, which is +20mV. Right now I'm 12 hour prime stable. I want to bump up the bclk up to 200 and be 12 hour prime stable.

I tried bumping up the bclk to 195 and core voltage to +80mV (1.33v), QPI up to +80mV, and DRAM up to 1.65. It fails 5 minutes in.

Besides cpu voltage, vtt voltage, and ram voltage, what other voltage increases help with hitting 200 bclk?

Here's the rest of my specs:

i7 920 d0
Foxconn Bloodrage
6 GB OCZ Platinum 1600 @ 7-7-7-24
Sapphire 4890 Vapor-X
X-Fi Titanium Fatal1ty Pro
Corsair 620HX
Viewsonic vx2255wm 22" LCD widescreen
Lancool PC-K62
7 64-bit Ultimate


CPU Features
PPM ......................................: Enabled
EIST .....................................: Enabled
CxE........................................: Disabled
Execute Disable Bit ..................: Enabled
Virtualization...........................: Enabled
CPU Write Back Cache ..............: Enabled
Hyper Threading ......................: Disabled
Active Processor Cores .............: All
Current Feedback Override ........: Enabled
CPU QPI Latency .....................: Auto
IOH QPI Latency ......................: Auto
CPU QPI Drive Strength .............: Auto
IOH QPI Drive Strength .............: Auto


Memory Settings
Memory Controller Settings
IMC Configuration ....................: Enabled
Channel Congifuration ..............: Independent
Channel Interleaving ................: 6 way
Rank Interleaving ....................: 4 way

Memory Timings
Virtual XMP .............................: Disabled
DRAM Timing Control .................: Manual
Current Timings .......................: 7-7-7-24-1-60-8-14-4-4
tCL (CAS Latency) ...................: 7T
tRCD (RAS to CAS Delay) ...........: 7T
tRP (RAS Precharge) .................: 7T
tRAS (Precharge Delay) .............: 24T
CR (Command Rate) ..................: 1T
tRFC (Refresh Cycle Time) .........: 60T
tWR (Write Recovery Time) ........: Auto
tWTR (Write to Read Delay) .......: Auto
tRRD (RAS to RAS Delay) ...........: Auto
tRTP (Read to Precharge) ..........: Auto
B2B CAS Delay .........................: Auto


All Voltage Settings

CPU Voltages
CPU Core Voltage ....................: Default
CPU Target Core Voltage ...........: 1.25625V
CPU Vdroop Compensation .........: Disabled
CPU VTT (UnCore) Voltage ........: +20mV
1.8 PPL Voltage Setting ............: 1.800V
CPU Clock Amplitude Ctrl ...........: 0.800V

Memory Voltages
DRAM Voltage .........................: 1.60V
DIMM1 Vref CA (Addresses) .......: x 0.500
DIMM1 Vref DQ (Data) ..............: x 0.500
DIMM2 Vref CA (Addresses) .......: x 0.500
DIMM2 Vref DQ (Data) ..............: x 0.500
DIMM3 Vref CA (Addresses) .......: x 0.500
DIMM3 Vref DQ (Data) ..............: x 0.500

Chipset Voltages
X58 IOH Core Voltage ..............: 1.10V
X58 IOH VCCA 1.1V .................: 1.108V
X58 IOH VCCA 1.5V .................: 1.506V
ICH10 SB Voltage ....................: 1.506V


OC Gear

Smart Boot Menu .....................: Disabled
Smart Power LED .....................: Disabled
Auto Detect PCI Clock ..............: Enabled
Spread Spectrum .....................: Disabled
CPU Clock Skew .......................: 0ps
IOH Clock Skew .......................: 0ps
Over Clock Recovery ................: Enabled


CPU Turbo .............................: Enabled
System Turbo ........................: Enabled

Clock Speed Control Center
CPU Bclock (FSB) ....................: 189MHz
QPI Link Fast Mode ..................: Enabled
QPI Multiplier ..........................: x18
CPU Core Multiplier ..................: x20 (21)
CPU Uncore Multiplier ...............: x16
Memory Bus Multiplier ...............: x8
PCI Express Bus Clock...............: 100MHz

[PiLsY]

CPU Voltages
CPU Core Voltage ....................: +100mv
CPU Target Core Voltage ...........:
CPU Vdroop Compensation .........: Disabled
CPU VTT (UnCore) Voltage ........: +120mV
1.8 PPL Voltage Setting ............: 1.616V
CPU Clock Amplitude Ctrl ...........: 0.700V

Memory Voltages
DRAM Voltage .........................: 1.72V
DIMM1 Vref CA (Addresses) .......: x 0.500
DIMM1 Vref DQ (Data) ..............: x 0.500
DIMM2 Vref CA (Addresses) .......: x 0.500
DIMM2 Vref DQ (Data) ..............: x 0.500
DIMM3 Vref CA (Addresses) .......: x 0.500
DIMM3 Vref DQ (Data) ..............: x 0.500

Chipset Voltages
X58 IOH Core Voltage ..............: 1.18v
X58 IOH VCCA 1.1V .................: 1.134V
X58 IOH VCCA 1.5V .................: 1.506V
ICH10 SB Voltage ....................: 1.506V
OC Gear

Smart Boot Menu .....................: Disabled
Smart Power LED .....................: Disabled
Auto Detect PCI Clock ..............: Enabled
Spread Spectrum .....................: Disabled
CPU Clock Skew .......................: 0ps
IOH Clock Skew .......................: 0ps
Over Clock Recovery ................: Enabled


CPU Turbo .............................: Enabled
System Turbo ........................: Enabled

Clock Speed Control Center
CPU Bclock (FSB) ....................: 200MHz
QPI Link Fast Mode ..................: Enabled
QPI Multiplier ..........................: x18
CPU Core Multiplier ..................: x20 (21)
CPU Uncore Multiplier ...............: x16
Memory Bus Multiplier ...............: x8
PCI Express Bus Clock...............: 102MHz

[Mescalamba]

Wouldnt work for me, too low VTT.. Dunno why, but my mobo can do higher freq only with VTT +200mV at least. Though rest is kinda identical, just my PCIe is at 100 MHz.. does that 102 really change something?

[PiLsY]

Bit more gfx speed and bclk tolerance. Its something to do with signalling between bclk and pcie - I dont think anyone quite figured out exactly what.

That vtt/vcore was based on his current overclock on that particular cpu. I need more than that for mine too .

[_AntLionBR_]

i7 960 @ 4.2GHz here (maybe you can help):

[CobraXP]

I have been too lazy to try G42. I need to try it and redo all my settings.

[Mescalamba]

Im still waiting for P11.

Ah.. hm, maybe I will try PCIe. Though I tried it on different mobo and its true it made GPU to work faster/better. At least according to 3DMark..

[homefry]

1.8 PPL Voltage Setting ............: 1.616V
CPU Clock Amplitude Ctrl ...........: 0.700V

What's the reasoning to decrease these 2 voltages lower than default stock?

Trying out 195 x 21 with vcore @ 1.37 and VTT @ 1.25 (measured with multimeter)... so far 1 hour stable in prime95.

[PiLsY]

Not needed. Just makes excess heat.



I wouldnt go up in such large voltage jumps. You're setting yourself up for spending hours tweaking voltages back down again with no idea of the relationship between them. Work your way upwards so you can learn how they all interact with each other.



HINT: Usually VTT around +-20mv Vcore is the way to go. More stable and lower temps if you get the vtt:vcore ratio right compared to ramming vcore to force mhz. Your initial stable overclock looks like your cpu wants vtt slightly above vcore (bios value).


Method:

1) You should first be testing bclk/uncore using a low ram and cpu multiplier but leaving uncore at 16x, then adjust vtt/vddr and vIOH(+vcca 1.1). However we know from experience here that IOH settings of 1.18v and vcca 1.1 @ 1.134v is enough to run up to around 205bclk. That leaves you only needing to adjust vddr and vtt to find your stable settings for 200bclk.

2) Once you have the bclk voltage dialled in you should find your ram limit - stay with a low cpu multi but up your ram multi to 8x while keeping the uncore ratio the same as you tested successfully before. Start at your current stable 190ish and work your way up. This time you only need to adjust vDDR. A +20mv VTT tweak can sometimes help stability if vDDR isnt working.

3) Finally you want to overclock the cpu. Leave in the previously dialled in voltages for bclk, uncore and ram and return to your 190ish bclk setting again. This time put the cpu multi back up to 21x and start clocking it up. You only need to adjust vcore this time. A +20mv VTT tweak can sometimes help stability if vcore sint working.


Dead easy really, just be systematic. Remember diminishing returns mean youll need to increase vcore and vtt quite quickly after a certain speed. You'll find that point yourself though - its different for every cpu.

[homefry]

CPU Voltages
CPU Core Voltage ....................: +90mV
CPU Target Core Voltage ...........: 1.25625V
CPU Vdroop Compensation .........: Disabled
CPU VTT (UnCore) Voltage ........: +100mV

These voltage settings in the bios give me a reading of vcore @ 1.37 and VTT @ 1.25 (with multimeter)

+80 on vcore and +80 on VTT fail 5 minutes in prime95 with bclk @ 195.

1.8 PPL Voltage Setting ............: 1.616V
CPU Clock Amplitude Ctrl ...........: 0.700V

I'll lower these once I have everything else dialed in.

[CobraXP]

1.8 PPL Voltage Setting ............: 1.616V
CPU Clock Amplitude Ctrl ...........: 0.700V

I tried this... never tried lowering it. I have raised it before but never did anything for me. My mobo and nb seem to be running about a degree cooler.
Thanks PiLsY

[PiLsY]

No probs, every little helps . That actually saves about 5watts at the wall under load - lol.

[homefry]

I think its my ram. I dropped the ram multi to x6 and ran prime for 2 hour on 4.2GHz.

If I set ram to 1.60 in the bios, I get 1.62 at idle and 1.64 at load with the multimeter, so I've been running at this voltage because the ram is spec'ed to run 1600 cas 7 @ 1.65 volts. 1.64 is close to 1.65.... Now I'll try running it with the bios voltage at 1.65. This gives me 1.67 idle and 1.69 load volts.

BTW, I've had more stability if I completely shutdown the computer and restart (not a reboot) after changing bios settings.

[PiLsY]

Not necessarily ram - vDDR controls uncore voltage too .

[saaya]

mesca, i dont think its your board that needs high vtt, its probably your cpu

very nice guide pilsy!
if id still have mod powers id make it a sticky or move it to the guides tweaks n faq section
and id actually go for higher vtt and IOH voltages (1.3v)

[homefry]

CPU Voltages

1.8 PPL Voltage Setting ............: 1.616V
CPU Clock Amplitude Ctrl ...........: 0.700V

Why didn't you say to set it to the lowest 1.8 PPL?

There's a 1.603 setting.

[PiLsY]

Won't boot for me over 200bclk. 1.616v is fine up to 221 bclk. Didnt want to suggest you try something that I can't confirm works . Try it, no harm done apart from an oc recovery...

[saaya]

lower pll is better on air?
interesting...

[homefry]

alright 4.2 is being a bigger pain than ever.

I like to be 10 hour prime stable and a lot of these settings are 20 pass Linx stable and 2-4 hour prime stable. So the only way to test my settings is to run a full 10 hour prime and if it fails, then tweak again and then run 10 hour prime run again. It's using too much power.

I'm just dialing in a 4.0 OC and lowering as many voltage settings as I can.

[PiLsY]

Wouldnt so much say better, more that pll default volts is too high. Makes a small temp difference but only gains you mhz if you were right at the limit of your cooling.

[PiLsY]

Prime fail / Linx pass is normally either vtt or vddr. Possibly IOH but unlikely. Set all three high and tweak down. If stable reduce IOH back to previous value first, then vddr and finally vtt. Start with +140mv / 1.72v / 1.24v. Let us know if that still fails.

You are using linx with at least 75% of your ram total set arent you? With 6gb installed I usually test with 5gb.

[LennyRhys]

Now it's my turn to aim for 4.2GHz, however it's looking doubtful. I have 4GHz rock solid (191x21) with only slight increases in vCPU and vTT, but like most overclockers I'm just UNSATISFIED!

Really struggling to get 200bclk stable; just tried 200x19 (turbo off, so 3.8GHz) with VTT at +240mv, vDDR at 1.67, and the suggested voltages of 1.134 and 1.18 for chipset, and the PC shut itself down about 2 mins into prime. The CPU is at 1.3v...huh?

I'm very familiar with the last generation of hardware and safe voltages, but not so much with X58 and i7. What's the 1.65 memory limit all about - is it a fairytale? And what about VTT, which I've had up to 1.4v but to no avail...?

EDIT: Upping vdimm to 1.68 (bios) affords a huge increase in stability at 200 bclk...looks like I've found the culprit. If I leave everything else as it is, prime fails within seconds. Progress!

EDIT #2: Well I finally solved the mystery: my D0 plateus at 4.1GHz...anywhere near 200bclk and it wants volts, which is baaaaaaad The bclk is stable at 200 with VTT @ +220mv and vDDR @ 1.68 (any lower with either and prime just fails). With the CPU at 3.8GHz (200x19) it's great...however with the CPU at 4.2GHz (x21) even with vcore of 1.4 the PC just shuts down spontaneously. Too hot for air, but I'll try 4.1GHz (possibly overnight) as all the voltages for 195 bclk are significantly lower: CPU +120mv, VTT +120mv, vDDR 1.64v.

[PiLsY]

Dont be afraid to give it more vdimm. The only rule is vdimm should never be more than 0.5v higher than vtt. You are aware that turbo generates more heat than a straight multi arent you? Id test to see how high you can get your bclk/mem/uncore first. You may well have more luck reaching 4.2ghz with the 20x multi. You'll probably need a bit more IOH - 1.24v gets me all the way to 216bclk.

Youll also find your cpu will prefer either odd or even multi's. Difference is usually around 30-50mhz. Most 920's prefer an odd multi.

Drop your cpu multi to 12x, see if you can get the bclk to 210 stable. Ram @ 8x uncore at 16x. +340vtt for air is about the limit. This will allow you to use vdimm to around 1.85v taking into account vtt droop. Cant see you needing more than 1.75v though, most likely around 1.72v.

[therager]

Now it's my turn to aim for 4.2GHz, however it's looking doubtful. I have 4GHz rock solid (191x21) with only slight increases in vCPU and vTT, but like most overclockers I'm just UNSATISFIED!

Maybe you should try first 210*19 combination, so you'll have higher ram frequencies on 4ghz cpu - with x8/x16 multi - from 1528mhz mem/3056mhz uncore to 1680mhz mem/3360mhz uncore . And then about 4.1ghz, the same combination - 215-216*19. It's harder to make it stable, but try it .

[homefry]

how high can ram volts go?

I have a sinking feeling my ram is holding me back. It's running 1600 7-7-7-24, which is tight already.