The i5-760 OC Club - Page 2

Mine at 4.1ghz; Prime95 run 4hrs with 1 error (core-0). IBT runs 20x without errors at Maximum.
Not sure what up with prime95 ;(

I first responded to TJ's question there 4 months ago. He linked my response as a guide for others but I never meant for it to be a guide. Nor have I ever thought it was that great of a guide for others to follow. So now a little belated I'm coming back to edit the post and try to turn it into something a little better for others to follow. I'll leave my original response at the end of the end of the post.

First off I recomend obtaining a few utilities for overclocking.

You will need CPU-Z - http://www.cpuid.com/softwares/cpu-z.html

Temp Monitoring. I like Realtemp but Coretemp, or HWMonitor will work just as well also.
http://www.techpowerup.com/realtemp/


Stability testing. I use Intel Burn Test (IBT) as well as Prime 95.

IBT
http://www.xtremesystems.org/forums/...d.php?t=197835

Prime 95
http://www.mersenne.org/freesoft/default.php

Also it is a good idea to make a template of all of your BIOS overclocking options. Save it to notepad, Print a few copies. I'll include one of mine so you know what I'm talking about. Mine may look different if I have a different brand of motherboard and different BIOS options. Generally though just make it look like your BIOS screen. Where you can start and the top and work your way down in order. I use the templates a lot to keep track of different changes to settings as I try them. And I'll save different copies to notepad for stable settings or just where I left off at while testing. They also come in very handy for posting your current settings here on OCN when asking for help. Makes it easy to say "this is where I'm at".

Ok now as you probably already know each i5 760 is slightly different from the next. One of the major differences will be the vcore that it requires to run at stock. I started off by finding out what that voltage was and using that as my starting point for my overclock, I suggest you do this as well. Reset everything to stock or reset optimized defaults. Open CPU-Z, Now run Prime 95 small fft with everything stock. Take notice to v-core in CPU-Z and take a screen shot, validate it or just write down the stock load voltage. Saving a screenshot with CPU-z and Realtemp or HWMonitor with Prime 95 running in the background could come in handy.



Once that is done you have a good place to start with on your v-core. Basically you want to go into BIOS and take v-core out of auto and set a voltage that will give you the same load voltage as stock. Due to Vdroop this setting will be slightly higher than the vcore in CPU-Z. Your BIOS might tell you what the stock setting is or a program like Turbo-V could tell you otherwise you will have to do a few trial and error runs to get it.

The frequency of the CPU is determined by 2 settings. Baseclock & CPU Ratio. Multiply them together and you have your frequency. Raise either one and you are overclocking.

Memory frequency is also tied to the baseclock and becomes quite important when overclocking. Raise the baseclock and your memory speed raises as well. Base clock multiplied by the memory multiplier gives you the memory speed. I believe that on most Asus Bios's this memory multiplier is hidden. Instead they just give you the options of the memory speeds available based on the different multipliers. It works well when starting new overclock to drop to the lowest multiplier which will be 2:6 or can easily be thought of as X6. Takes the pressure off the RAM as you raise the baseclock. Then once reasonably stable you can bring the memory speed back up by raising the memory multiplier back up if needed.

Your memory timings can be left in auto but I prefer to lock them in to the stock timings for the RAM. There is alot of settings in the timing section the ones that need changed or locked in should be at the top of the page. I think when people first look at the timing section there is usually some sort of OMG impression but then after taking a little closer look they figure out that setting those 9-9-9-24-1t timings (or whatever your RAM timings is spec at) are pretty simple. First 9 is the CAS Lantency (CL) and is the fist setting in the timing section, 2nd 9 RAS to CAS delay (tRCD) is the second setting,3rd 9 RAS Precharge (tRP) the third setting, 4th number 24 in this case is cycle time (tRAS) and is fourth setting. Then the command rate (1t,2t or could be listed as 1N or 2N) is just a couple of settings down.

Once that is done you will need to lock in a few other voltages to appropriate values.

Disable Speedstep, C1E, C-State tech, LLC, CPU & PCI spread spectrum, and clockgen if you have it.

Dram/Ram Voltage - Find the recomended voltage for your RAM. Somewhere around 1.35v - 1.65v. If you have RAM that is lower voltage than 1.65v you might find that you need to raise it some. Start with the stock voltage for the RAM though.

PCH - 1.05v - this is stock and the lowest setting available. Just lock it in so that once you start overclocking it doesn't go bouncing up and overheating the chipset.

CPU PLL - 1.80v - Just a good starting point here and it is highly doubtful that you would need to touch it again.

Uncore voltage which gets tricky first of all because every board manufacture calls this voltage something different and Asus seems to call it muliple things depending on which BIOS you have. For asus it is probably IMC or IMC Voltage. Could also be QPI/Dram Core Voltage. Is also more commonly listed as VTT by other manufactures. If you have trouble finding it just post listing the different options and myself or someone else should be able to pin point it for you in nothing flat. Also forgive me if I keep calling it uncore voltage or VTT and it is listed as something else for you.

OK here is a hard rule you HAVE to follow. uncore/VTT/IMC voltage HAS to remain WITHIN .5v of the DRAM Voltage. This can be a problem with 760's because stock uncore voltage can be quite low in the 1.10v range and it is common for RAM to be rated at 1.65v. If you were to run that combo expect to be RMAing your CPU to Intel sooner rather than later with a damaged Internal Memory Controller.

Dramatics out of the way the uncore voltage can primarily be thought of as the voltage for the Internal Memory Controller (IMC). There is a little more to it but that is an easy way to think of it. Just keep in the back of your mind that the baseclock can be somewhat VTT dependent at times and the vcore can also have effect on the stability of the IMC. Generally you want to run this voltage as low as you can keep stable while staying within that .5v of DRAM Voltage limit. Anything over 1.3v is getting pretty high but generally is considered safe to 1.4v although that would make me a little nervous for long term 24/7 use. For starting out a overclock on my 760 I like to set it to 1.3v and get everything else stable first. Then go back and lower it a little at a time testing for stability and lower it as far as I can keep stable at.

CPU Ratio. 21 or 20 are going to be your best options with the 760. I like 21 and I suggest you start with it. Try out 20 though afterwards and compare the 2. I can run the same CPU frequency at a lower vcore with 21 than 20. Your chip might like 20 better and you won't know until you try both. With lower frequency RAM a CPU Ratio of 19 might become an attractive option but anything over 200 on the baseclock can become rather challenging.

Settings that I didn't cover I'm intending to leave in auto to start with. Yes there is more settings and more fine tuning you can make. I'm just not doing it here.

Ok now you have some values locked in. Go ahead and bump the baseclock up to 150ish and then save and load windows. Run IBT for 3-5 passes of standard. Have Realtemp running while doing so. Shouldn't be a problem. I like to watch the MAX temps row in real temp. You should be looking at keeping the max core temps below 80C.

Now go back in and bump the base clock up 4MHz or so. Then retest. Keep doing this until you fail the test. Should be able to make it to mid 160's to low 170's at stock voltage. Now once you fail go back into BIOS and bump the vcore a minimun increment maybe 2 (.00625v -.0125v) Then rerun the test. If you pass yippee keep going with the baseclock. If you fail again bump the vcore again. Usually around 175 or so I'll start just going 1-2MHz at a time. Now just keep repeating until you hit goal. 181 X 21 will give you a nice 3.8GHz overclock 191 for 4.01GHz.

Once where you want to be up the ante on stability testing and make adjustmenst to keep it stable. I do a series of progressively harder tests. Starting with those 3-5 passes of IBT standard. Then moving to 10 passes of Max. (if you have more than 4 GB of memory I'd suggest running high then very high before moving to max.) Then 20 passes of Max.

AT this point is when I go back and seperately raise the memory frequency by changing the multiplier and lowering that uncore voltage. Raise the memory frequency first then retest . Then try to get the uncore voltage as low as you can (while respecting the .5v window) and still pass 20 pass of Max IBT.

Once I can pass that I move on to Prime 95. Running 10-12 hours of Prime 95 small fft and then Prime 95 Blend for a minimum of 12 hours.



I'll save my edit for now but am considering this a work in progress. Feal free to suggest changes or something I missed or need to add. Post here in the club or PM me suggestions.

~sizzzle~






















***Original response***

Pure Luck !

To start with I checked stock load voltage by setting optimal defaults and running Prime95. http://i771.photobucket.com/albums/x...r/5d0fb44a.png Then I locked in that voltage (1.035v). Cut the memory to 2:6 and loosened the timings up. Set the VTT high enough to keep it out of my way (1.3v) Everything else was either left in auto or set to stock settings. Then pushed up the baseclock until I couldn't pass 3-5 passes of IBT standard. Then bumped the vcore and repeated.

Now I was very suprised when I made it to my goal of 191 as quick as I did and was passing 20 passes of IBT max at 1.129. http://valid.canardpc.com/show_oc.php?id=1447345. I then gave it a small bump and ran Prime95 then folded a 6701 WU which isn't an easy task without any problems. At that point I was at 1.14v with a few dips to 1.137v. Then after raising memory back up to 2:8 I ended up having to bump the vcore one more time after a 101 BSOD several hours into Prime Blend. Tested some more, lowered the VTT back down a bit, then dropped the timings and ran 12 more hours of blend. Then I started folding again on it and ran it for about 4 days straight at 100% load without a hiccup. Really that 1.14v is bouncing a bit up to 1.15v but is still mostly at 1.14v when under the heaviest load.

To more clearly answer your questions I started at a vcore of 1.035v. First couple bumps were .025v then a few .0125v bumps then a few minimum bumps of .00625v.

Now what happens when the voltage isn't enough for the clock? Bad stuff . Really isn't too bad if you know what to expect. At worst it won't Post and you will have to clear CMOS which will load the default BIOS before any changes were made to it. Another reason to always write down every setting you try. If you can save the last known good settings into a profile before changing anything it will save you some time. Other than not posting on restart failure can range from freezing, or restarting while loading windows to the dreaded Blue Screen Of Death or more system freezes while testing.

Should also note that bad overclocks have also been noted to cause nasty stuff like HDD corruption. Any important files should probably be backed up on an external until you get stable. Or maybe that's just my excuse for overclocking a brand spanking new system before I get a chance to save anything important on it.

tl;dr Pure Luck, just Pure luck !
Edited by ~sizzzle~ - 3/3/11 at 10:56am

Mobo could make a little difference. I picked mine with the power delivery and cooling in mind because I was thinking of pushing it a bit and running some benchmarks for kicks when I was still picking parts. PSU might be helping me a bit also.

Sorry I don't have it in my sig. Here are the highlights.

i5-760
EVGA P55 FTW
Mushkin Blackline 1600MHz 7-9-7-24-2T stock spec
Seasonic M12II 620
Corsair A70 CPU Cooler
Asus Direct CU TOP GTX460 + 9800GT PhysX


Shoot after doing some browsing of top baseclocks for the 760 I'm thinking I should have bought a Biostar Tpower.
Edited by ~sizzzle~ - 11/3/10 at 9:19pm

Well, here's my OC!

Nahte27 4.116GHz|1.35v IBT, Prime 95, Gaming, and Folding@home stable!

I love my new i5 760 but I wish it didn't need as much voltage as it does to run at this speed . I see a lot of i5s running speeds well above 4GHz with ~1.3v or less. I have to run mine at 1.35 in BIOS, and it's registered as high as 1.388v in CPUz, which seems to be a bit high... Any lower on vcore or VTT and it's unstable.

But at least temps are good, and it's stable at a good speed!
Edited by Nahte27 - 11/3/10 at 9:40pm

Which test are you running in Prime 95 and what is your vcore and VTT or actually it's an Asus so it's probably IMC ?

Shoot actually just list all of your settings. I make no claims to being any sort of expert but I'm sure someone else if not myself can help you get that thing stable at 4.0. It's just easier if we know where you are at.


Memory multi
Memory Timings

C1E
Speedstep
Cstate

Baseclock
CPU Ratio
VTT/IMC/QPI whatever it is called on your mobo LOL

CPU PLL
Dram Voltage
QPI Frequncy



No, but having RAM that will easily run stable above where it is set will keep me from dumping more voltage on it trying to fix those harder to deal with uncore instabilities that creep up when you're overclocking the RAM also. That is why I start out with locking in the 2:6 memory multi and loosening timings. Takes the RAM out of the picture and lets me overclock the CPU without the IMC and RAM throwing their own problems into the mix.
Edited by ~sizzzle~ - 11/3/10 at 10:10pm

Greetings!

jedi304 4Ghz | 1.25v Stable in OCCT, and IBT. Runs 24/7 and some gaming here and there.

http://valid.canardpc.com/show_oc.php?id=1385294

Read it and weep.

Impressive