Issues overclocking my i5-750

epiphanyplx

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Okay, so I just recently bought an e.c.o. alc cpu cooler for my i5-750 with hopes of overclocking it! My motherboard is a Asus P7P55D.

I read the Tom's Hardware guide to overclocking the i5-750 as well as some other sites, since I hadn't done it before. I downloaded Core Temp, cpuz64 and LinX. I started off cautiously because I would be so sad if I hurt my baby and raised the BCLK by 10. I booted up, cpuz64 told me I had given myself another 200 mhz, running LinX with core temp told me that heat wasn't going to be a problem at this setting. So I kept doing this, eventually having to stop at 3 ghz. As soon as I go over that LinX starts putting all of my cores at 80 or so and Intel says 72 or 74 should be the highest it goes.

I have read lots of other people saying they get 4 "on air." Now I don't want to burn out my poor little cpu but with the cooler I have (which I was at least led to believe is good) I feel I should be able to get 3.6 or at least 3.4 without any issues. Am I wrong?

Another question: I have 4 gigs of G.Skill dual channel ddr3-2000 ram (CL9-9-9-27 1.65 V) With how I have it overclocked now it's only running at 752 mhz (DRAM Frequency) and it should be running at 1000, right?

I noticed in the BIOS that when I increase the BCLK frequency it allows the ram to be faster. Should I just increase the BCLK frequency and decrease the multiplier to still achieve 3ghz or is that silly for some reason? SHould I change my ram voltage to 1.65?

Please help! This is my first time overclocking and I want it to be a success :D

- Thanks,

Andrew
 
Solution
Sounds like you need to read more about overclocking but I'll try to help a bit.

Firstly, you only want to raise voltages when it's needed. So, you raise your base clock and then test with LinX (I prefer Intel Burn Test, but they're basically the same). If you get any errors, then you need more voltage. Depending what stage of overclocking you're at (nearing your OC limit or just getting started) will depend how you go about upping the voltage but generally 0.01-0.03V increase to Vcore is good, then reboot and check if it's stable. If not, do it again. At about 0.1V Vcore increase, if it's still not stable then the problem is likely with not enough Vtt/IMC voltage so do the same process until stable.

Starting voltages I believe are...
G

Guest

Guest
http://www.overclockers.com/3-step-guide-overclock-core-i3-i5-i7/

I found this guide very helpful.
Keep reading and asking questions. I would suggest to stop with the trial and error approach for now. Return BIOS to optimum defaults, reboot and while in a stock configuration learn about overclocking. Enjoy
 

epiphanyplx

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Okay this guide so far has been great but it has raised further questions. Why is it that when I change the voltage of my RAM to 1.65 my cpu temperature rises?
Also, Intel told me not to let my processor operate over 72 but Core Temp has some "Tj. Max" value. Are they different?
Also, my bios doesn't have IOH or CPU VTT voltages, so not sure what to do there.

How much of a difference will it make to run my ram at 1000mhz instead of 433 or whatever it was at?

Thanks again for the help
 

shiftstealth

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the TJ max is around the max temp the CPU can take before sustaining instant damage.

Operating over 72C will decrease the life of the CPU from like 10 years to about 5.


If your running dual channel ram at 500Mhz it would be DDR3 1000MHZ ram 2X500=1,000.

If you wanna run your ram at 1000mhz or DDR3 2000Mhz you need to buy really good ram to do that most DDR3 Runs at 667 or 1333Mhz you might get it to 1400 or 1450.


PS i see you have DDR3 2000Mhz i think your limiting factor that i overlooked myself was the VTT voltage. It can be listed as a few things.

Have you increased any Voltages other than the ram?
 

epiphanyplx

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No, at the moment I just have it set to: 200 bus speed and 16x multiplier. Setting the bus speed up was how I increased my DRAM frequency because it doesn't seem like I can increase my RAM ratio or whatever on this board independently. The ram voltage is the only voltage I changed; I figured 3.2 was good enough (Although I have some sort of water cooling thing so I would think I could go higher) and didn't want to mess anything up.
 
You should not let the mobo choose auto voltages... it's probably way over volting. Increase the base clock, check stability and if it's not stable raise the voltages. If you don't have VTT, you will have IMC. Same deal. First try raising vcore, after around 0.05V increase, do the same to IMC. The new Intel specs list max Vcore and max VTT as 1.40V.

RAM voltage is only useful for RAM speeds, it won't help CPU stability. Most RAM these days requires 1.65V to run at their rated speeds. It can add to CPU heat because the RAM is connected to the CPU - as in, there are pins for RAM. However, it shouldn't add a lot of heat. You'll mostly get heat from Vcore then Vtt/IMC.

My settings for 175x20 with turbo ON, is Vcore 1.30625 Vtt 1.20635 DRAM 1.65 and the rest on auto. This gives 3.68ghz normal and up to 4.2ghz turbo and my temps max at 62C on air (Zalman CNPS10X Extreme cooler)

EDIT: Read comments over again. The anything over 1333mhz RAM is considered an OC and acheivable only by OCing the base clock. Basically high speed RAM just gives more head room to OC the CPU. You could easily run your 2000mhz CL9 at 1600mhz CL8 or better (1600mhz CL7 even). Ram ratios and, well, any ratios is from older generation CPUs. The i3,i5,i7 line up is handled differently. You get multipliers and base clock. RAM you can typically set to 6x, 8x, or 10x base clock multipliers, although some mobos will display the actual speed and not the multiplier. My 1600mhz CL8 1.65V RAM is running at 1400mhz CL7 (175x8).
 

epiphanyplx

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Okay, so I tried just copying your voltages to see if it works, and it seems to. I feel like this is cheating though! If I wanted to do what everyone suggests and raise it a little bit at a time, what voltage should I start at? I assume raising a voltage raises the temperate? Real Temp has my TJ Max as 97, one of my cores got to 93 during Linx's test. Is that okay? Also, my second and fourth core are consistently 10 degrees hotter than the other cores during Linx. Any reason for that?

Another question- what is a bigger factor with RAM, the speed (mhz) or the other numbers, the latency? If the latency is more important, how would I set my ram to be faster?

Thanks for all the help!

EDIT: Another question, when you say "my temps max at 62" is that at 100 percent load or just throughout the day, doing what you normally do? Thanks again!

 
Sounds like you need to read more about overclocking but I'll try to help a bit.

Firstly, you only want to raise voltages when it's needed. So, you raise your base clock and then test with LinX (I prefer Intel Burn Test, but they're basically the same). If you get any errors, then you need more voltage. Depending what stage of overclocking you're at (nearing your OC limit or just getting started) will depend how you go about upping the voltage but generally 0.01-0.03V increase to Vcore is good, then reboot and check if it's stable. If not, do it again. At about 0.1V Vcore increase, if it's still not stable then the problem is likely with not enough Vtt/IMC voltage so do the same process until stable.

Starting voltages I believe are 1.15V Vcore and 1.08V Vtt or thereabouts. Depending how high you want to go you'll find that you need incrementally more voltage for the same clock increase, because it gets less and less efficient.

As for temps, you're way way too high. When I say 62C max, that was running Prime95 overnight. It sounds like you need to remount your heat sink. It should not be running that hot at all. Make sure you apply a good quality compound like Arctic Silver 5. You can try to find mounting guides for that specific cooler, but you can check this out http://www.arcticsilver.com/pdf/appinstruct/asta/ins_asepxy.pdf.
The problem could also just be not enough pressure. When you screw down the heat sink, make sure to switch which screw you're tightening so they all get tightened about equally, if you do 1 fully then the next, then the next, then the last it will go down crooked and probably squish the thermal paste over to one side. I have a feeling this might be the case since your 2 cores are significantly hotter. Generally Core0 is the hottest by up to 8C above the lowest, and then Cores 1, 2, 3 are within a few degrees of each other.

As to RAM, speed and latency are equally important. Wikipedia has a good page of info http://en.wikipedia.org/wiki/Memory_Timing#Memory_timing
Basically, slower RAM with faster timings can equal fast RAM with slow timings... so 2000mhz CL9 could be about equal to 1800mhz CL8 or 1600 mhz CL7. Honestly tho, RAM speed has minimal effect on performance. First, learn how to OC your CPU and once you're comfortable then worry about squeezing the most speed out of your RAM.
 
Solution

epiphanyplx

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Thanks for the suggestion, it worked like a charm!!

I removed the heatsink/water cooling contraption and removed the compound I had put on. It looks like it was way too much! I read a guide and reapplied it properly. In addition, I think you were right on another count; I hadn't screwed the thing in all the way! Not even close, no idea what distracted me at the time, but making those two changes lowered my temperatures dramatically!

I am now overclocked at 3.6 (200x18) with no voltage increases. I was trying to mess with the voltages to get 3.8 or something a little higher but when I could make it go into windows it would have errors during stress testing. I decided that going from 2.6-3.6 for $50 (price of the fan) is totally worth it and I'm going to let it be for now.

My max temperature now after 15 mins or so of Prime95 running the large test or whatever it's called (all cores reading at 100%) is 70 69 68 71.

Are those temperatures okay?
Thanks so much for the help!

EDIT:
Wow okay I backed it down to your settings and now my max temperatures are more like 59 59 58 57
I guess you were right, with the voltages set to auto it must have set them higher than they actually need to be. I'm just going to stick with your settings unless they give me any problems :D

Thanks again for your help, wolfram and everyone else.