How to slightly overclock an i7

[neiby]

I've been reading about overclocking (never done it before) and it seems like if I just want to do a slight OC on an i7, it shouldn't be too bad. I've read on here that some people are getting 3.4 or 3.5 GHz without even increasing their voltages. They speak of tweaking the base clock and the multiplier, but not much else.

The default base clock on this is 133 MHz with a multiplier of 20 (or 21 in turbo mode.) Let's say I want to get to 3.4 GHz without tweaking any voltages. Is it as simple as going into my BIOS, lowering my multiple to 17 and raising the base clock to 200? Could it really be that easy?

As you can tell, I'm fairly noobish to this and would love to hear from someone who has done it.

I have an i7 920 in an MSI x58 Platinum mobo. I have a Vigor Monsoon III LT cpu fan for cooling. My CPU idles around 34-36C.

Any thoughts?

 

[Phantomaniac]

Welcome to the forums. As an owner of the same hardware, I can say you should probably be able to hit between 3.4-3.6Ghz without any voltage adjustments. Just go into your bios and set your base clock to 160Mhz (for starters) and disable turbo mode. Leaving your CPU multiplier at 20 should be fine, but lower your DRAM multiplier to 3 (technically 6) for initial testing. I use Prime95 for stability testing and HWMonitor for temperature monitoring. On each boot, run Prime95 for 10-15 minutes as a primer. If that succeeds, reboot and bump up your base clock 5Mhz. Repeat until you get a failing test, in which case you have a good idea of your limits on stock voltage. After this point its a good idea to test your previous base clock setting for much longer to ensure stability (1+ hrs).

Oh one more thing: I'm not sure if it's just my motherboard or the whole MSI X58 Platinum series but the auto voltage adjustments are AWFUL. During my first overclocking run, leaving it on auto bumped my CPU voltage from 1.2v to an alarming 1.5v! I'd suggest you manually adjust your CPU voltage to +0.00.

Cheers!

 

[neiby]

Oh one more thing: I'm not sure if it's just my motherboard or the whole MSI X58 Platinum series but the auto voltage adjustments are AWFUL. During my first overclocking run, leaving it on auto bumped my CPU voltage from 1.2v to an alarming 1.5v! I'd suggest you manually adjust your CPU voltage to +0.00.

Cheers!

Set the CPU voltage to +0.00? Is that correct?

 

[Phantomaniac]

Originally posted by: neiby

Oh one more thing: I'm not sure if it's just my motherboard or the whole MSI X58 Platinum series but the auto voltage adjustments are AWFUL. During my first overclocking run, leaving it on auto bumped my CPU voltage from 1.2v to an alarming 1.5v! I'd suggest you manually adjust your CPU voltage to +0.00.

Cheers!

Set the CPU voltage to +0.00? Is that correct?

Yes. This ensures that the default voltage will not be adjusted.

 

[neiby]

I gave those settings a try. My PC rebooted a few times on its own and then shut down completely. No power. Nothing. I unplugged it from AC and hit the button to clear CMOS. Nothing.

Luckily, another guy on another forum happened to hear my plea for help and he suggested pulling the ATX cable before clearing CMOS. Thank god that worked!

But now I'm really freaked out about trying to OC this machine. I'd be happy with just getting it to 3.2 GHz or something, but I don't know if I even want to touch it now.

 

[neiby]

Also, I'm not 100% sure I changed the right parameters. There wasn't one called DRAM multiplier, but there was one called memory ratio. That's the one I set to 3. And on the CPU voltage parameter I tweaked, there was no option for +0.00. There was either AUTO or various negative or positive values.

I'm sure glad pulling the ATX cable helped. That scared the crud out of me. I've only had this PC for six days!

 

[Phantomaniac]

You have to scroll through the negative/positive values until you find +0.00. Trust me, it's there. If you left it on auto then I wouldn't rule it out that the auto voltage adjustment caused the shut down.

 

[neiby]

I did scroll around and didn't see it, but it was there when I looked later. The story gets better. The next attempt blew my cheapo power supply! I replaced it with a good Thermaltake 850w PS so I should be ready to try again.

 

[Phantomaniac]

Wow man. I have all of my voltages manually set to stock in my bios to make sure they weren't being auto adjusted out of range. If you want I can give you my full configuration.

 

[Denithor]

If there isn't a +0.00V then just set the smallest +V available in there.

And with your BLCK at 160 you should set memory multi to 8 (4) and your RAM will run at 8*160=1280mhz, well below the rated 1333mhz.

And - pulling the ATX cable - please tell me you unplugged the system before clearing the BIOS - please?

Here's a quicky guide I wrote a few days ago to help another guy.

Actually, you just set your CPU and RAM multipliers independently of each other and they work off the same "base clock" (called blck by most people).

i7 920 @ stock:
BLCK = 133
CPU = 133x20 = 2.66GHz
RAM = 133x6 = 800MHz or 133x8 = 1066MHz

Some motherboards don't list the multipliers as such, rather they list a memory speed (IE DDR3-800 is equal to a 6 multi, DDR3-1066 is 8 multi) and you just have to know how to convert. The i7 965 features additional multis of 10 and 12 (corresponding to "stock" blck speeds of DDR3-1333 and DDR3-1600, respectively).

Now, overclocking. Remember you can adjust the CPU & RAM multis independently.

920 @ 20x150 = 3GHz
RAM @ 6x150 = DDR3-900 or 8x150 = DDR2-1200

920 @ 15x200 = 3GHz
RAM @ 6x200 = DDR3-1200 or 8x200 = DDR3-1600

920 @ 20x200 = 4GHz
RAM @ 6x200 = DDR3-1200 or 8x200 = DDR3-1600

920 @ 18x222 = 4GHz
RAM @ 6x222 = DDR3-1333 or 8x222 = 1776

920 @ 16x250 = 4GHz
RAM @ 6x250 = DDR3-1500 or 8x250 = DDR3-2000

General notes:
-If you want a higher blck just remember to turn down your memory multiplier if your RAM cannot handle the new speed.
-Keep in mind that DDR3-1333 will handle up to a 222blck (on a 6x multi) which will net you up to 4.44GHz on i7 920 with a 20x CPU multiplier.

EDIT: For a lot more info, go read this article. Should clear things up nicely. Just be careful when upping the voltage, those guys (nut jobs) at xbitlabs like to push the envelope with their voltage.

 

[neiby]

Yes, I did disconnect the power before digging around inside.

Thanks for all the tips. I think I'm getting a good handle on this finally.

 

[hexoroid]

Hello Phantomaniac i am trying to find out my stock voltage.. i tryed setting CPU VCORE to auto but than CPU-Z reads 1.3 voltages so i went
into bios and set it to 1.19375V my memory is 1600 MHz and i want to keep it on 1600 frequency so far CPU-Z reads it fine
my question do i need to change anything here.. like CPU VTT Voltage [+300mV] ? PWM Frequency [933 KHz] ? If you can tell me
what you have set yours as.. btw i overclocked to 3.2 i am thinking to keep it on 3.2 if i want to keep my memory on 1600 Mhz (2:10) .. or if you can give me your settings and what kind of memory you have and should i change anything in my current settings thanks a lot.

Memory Spec:
Brand CORSAIR
Series DOMINATOR
Model TR3X6G1600C8D
Type 240-Pin DDR3 SDRAM
Tech Spec
Capacity 6GB (3 x 2GB)
Speed DDR3 1600 (PC3 12800)
Cas Latency 8
Timing 8-8-8-24
Voltage 1.65V
Multi-channel Kit Triple Channel Kit
Heat Spreader Yes

My BIOS Settings:


- Frequency/Voltage Control
Dummy O.C [Disabled]
Extreme Cooling [Disabled]
CPU Clock Ratio [20 X]
CPU Host Frequency(Mhz) [160]
CPU Uncore Frequency(Mhz) [ 3206MHz (20 X)]
Spread Spectrum [Disabled]
PCIE Frequency(Mhz) [100]

- Memory Feature
Memory Control Setting [Enabled]
Memory Frequency [1333 MHz / 2:10]
Channel Interleave Setting [6 way]
Rank Interleave Setting [4 way]
Memory Low Gap [Auto]
tCL Setting [8]
tRCD Setting [8]
tRP Setting [8]
tRAS Setting [24]
tRFC Setting [74]
Command Rate [1T]

- Voltage Control
EVGA VDroop Control [Without VDroop]
CPU VCore [1.19375V]
CPU VTT Voltage [+300mV]
CPU PLL VCore [Auto]
DIMM Voltage [1.650V]
DIMM DQ Vref [+0mV]
QPI PLL VCore [1.400V]
IOH VCore [1400V]
IOH/ICH I/O Voltage [1.650V]
ICH VCore [1.250V]
PWM Frequency [933 KHz]

- CPU Feature
Intel SpeedStep [Disabled]
Turbo Mode Function [Enabled]
CxE Function [Disabled]
Execute Disable Bit [Disabled]
Virtualization Technology [Disabled]
Intel HT Technology [Enabled]
Active Processor Cores [All]
QPI Control Settings [Enabled]
QPI Link Fast Mode [Enabled]
QPI Frequency Selection [4.800 GT/s]

- E-LEET Tunning Utility Memory Readings:

Type: DDR3
Channels# Triple
Size: 798.3 MBytes
Channels# Triple
NB Frequency 3197.1 Mhz

DRAM FREQUENCY 799.6 Mhz
FSBRAM 2:10

 

[neiby]

I tried a BLCK of 160 and memory multiplier of 4 and my system didn't like it. It nearly finished booting. Vista had started and most of my startup applications had started when the system rebooted. So, I backed off to a BCLK of 145 and it seems to be fine. But that's not much of an improvement. I wonder if my memory really can't run that fast. Maybe I should try 160 again with a multiplier of 3?

 

[hexoroid]

Well i am on 3.21 Ghz on my computer currently i run on 2:10 so that way
i get 1600 mhz on my memory but i am just not sure if i can lower CPU VTT Voltage [+300mV] currently i put it on 200 and its working fine i dont know how much more i can lower it ?qpi pll vcore ioh vcore ioh/ich i/o voltage i set it all to auto and lowered pwm frequency to 800 mhz so far so good i would just like somebody to post their bios profile
which would help lots of users here.. there is mine up above on 3.2 ghz

 

[neiby]

What about this? If the problem is actually my memory, I could further increase the BCLK and decrease the memory multiplier. A BCLK of 170 would give me a cpu clock speed of 3.4 GHz and a memory clock speed of 1020. I wonder how that would work.

 

[hexoroid]

Try it.. i have to keep my memory multiplier at 2:10 because i want to keep 1600 mhz memory.. so far everything is good i i would just like to know whats the lowest that you can go on the voltage.. what is your current core voltage at ?

 

[neiby]

I was told to manually set my CPU voltage to +0.00 since Auto can set the voltage way too high.

 

[hexoroid]

when i set it to 0 i can not boot up with my settings.. but when i do "load defaults" it is on 0 and i boot up fine.. i dont know why