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My first OC. i5 750. How'd I do?

Last response: in Overclocking
August 2, 2010 9:29:05 PM

So I had never touched a BIOS setting before, but I was dead set on overclocking.

I have a i5 750, GA-P55A-UD3, G.Skill 2x4GB Ripjaws.

Before I overclocked my temperatures were at 26C Low, 50C High during Prime95. This is inside a somwhat cool airconditioned room. Now after my overclock..

Other things I changed that you can't see from screenshot:

QPI clock ratio - X36
CPU V-Core - 1.2000V
QPI/VTT - 1.5000V
PCH Core - 1.0500V
CPU PLL 1.800V
DRAM - 1.64V

I'm currently running Prime95 blend test and through 30 minutes no errors so far. I'll be leaving it on about 6-10 hours.

I have a couple of questions.

1. My DRAM stock setting was 1333mhz at 1.500V. I set it to 1400 at 1.640V. Should I be worried about this increase?
3. Anything I should change, even if it passes Prime95 tests?
3. Should I be using another temperature monitoring software to monitor my RAM? Or does RAM heat = CPU heat?
4. I turned off Virtualization. What is virtualization? Do I need it?

Thank you very much. ;) 

More about : 750

a b K Overclocking
August 3, 2010 6:05:08 PM

I can only answer a few questions but it looks good though:

1- The RAM should be fine but I think 1.6v should be more than enough at 1400mhz, my Transcend aXe RAM only needs 1.6v @ 2000mhz and 9-9-9-24 timings. Just download and run Memtest and if it picks up no errors you're good to go. You may not even need to change the DIMM voltage to run at 1400mhz.

2- You say you changed the PCH Core and PLL voltages? I don't think you'd need to change those to get a good overclock, only extreme overclocks should need these changes.

3- From what I know, you can't monitor your memory temperature but I don't think it's a problem. And no, memory temperature does not = CPU heat.

4- I don't know what it does and if you need it, I just left it enabled because I figured it won't change anything if I turn it off.

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a b à CPUs
a c 100 K Overclocking
August 3, 2010 6:28:18 PM

For the most part, pretty good. Some things you should be aware of:

Intel states the Absolute Maximum voltages are 1.40V for both Vcore and Vtt/QPI. You currently have QPI at 1.5V. That is very, very high. Raise your Vcore to allow a lower Vtt. For example, at the same baselclock (175) I was using 1.31 Vcore, 1.21Vtt and had Turbo Boost enabled.

About your RAM: It's probably rated for 1.65V, that is very normal. With the higher voltage you can tighten your timings. For example, 1600mhz CL8 RAM could run 1400mhz at CL7.

You generally don't need to worry about RAM temps, and no there's not usually any way to monitor them. Extremely high end RAM like Corsair Dominators running full out might need RAM fans but for the most part it's uneeded.

I'm pretty sure virtualization is just to ensure some backwards compatibility for reading your sensors or something... On or Off shouldn't change much.

PLL voltage doesn't need to be touched

PCH voltage also generally doesn't need to be touched, unless you're running a lot of extra cards and what not. I have a GT240 in my 4x lane which goes to the southbridge (PCH) and boosting the voltage up to 1.15V helped stabilize that card. Under most circumstances tho, you shouldn't need to.
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a b K Overclocking
August 3, 2010 6:41:09 PM

+1 for Wolfram. 1.5vtt is way too much voltage. I even read it as 1.15 lol XD.

You should lower the VTT voltage, a lot. And then raise the CPU core voltage because 1.184 is pretty low. Try 1.25 vcore and see how it goes under Prime 95.
a b K Overclocking
August 3, 2010 8:42:04 PM

You might be confused. Every BIOS is different and some have the same names for QPI/DRAM and VTT voltage. They are all the same in most cases. If you are referring to your memory voltage as the DRAM voltage then 1.5v is fine. But you did say that your DRAM (memory) voltage was at 1.64v. Usually the BIOS calls the memory voltage "DIMM voltage".

I do recommend dropping the QPI/DRAM/VTT voltage to about 1.2v and again upping the CPU vcore to about 1.25v.
August 5, 2010 1:57:45 AM

Best answer selected by RelentlessMH.
August 5, 2010 1:58:27 AM

Thanks guys! Will tweak my settings and run some more tests. :]
August 5, 2010 2:17:21 AM

Actually.. wow. I apologize. I DID in fact have 1.150V for QPI/VTT Voltage. I mistyped when I made the post, DOH!

So my VCore is 1.225V,
QPI/VTT - 1.150V
PCH Core - 1.050V (This is default stock setting)
CPU PLL - 1.800V (This is default stock setting)

And oh, since I made this post I upped my BLCK to 180 for a nice round 3.6 GHZ. Temperatures only increased a couple degrees. I'm leaving it here, not going to get greedy.

It passed Prime95 with no errors. Did Small FFT test for 10 hours or so, and blend test for 12. I don't want to do too much torture testing (I love my new baby), I'll just play games and use my video/3D software over time and see how it does.

I wasn't able to tweak my ram from 99924 to 77720 without getting errors in Memtest no matter what I changed DRAM Voltage to.. so I've kept it at 99924 timings.