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Old February 17, 2011, 10:44 AM
draemn draemn is offline
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Join Date: Dec 2010
Location: Fort St. John, BC
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My System Specs


Overclocking and Clock Speeds:

Now, I'm a little lazy when it comes to over-clocking, but not in a bad way! When you start to overclock, if you have no clue what's going on, it's best to just slowly raise voltages/speeds and do tons of testing so you don't fry something. Well, thankfully the X58 platform has been extensively over-clocked, so there are lots of guidelines to give you a head start.

Please make sure you fully understand the dangers of overclocking and have read at least 1 basic guide before attempting the following! My advice is based on the fact that you will have to make the decision of what is safe, and not just follow my steps blindly.
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Starting: It's nice to start off with a profile of what should be a stable speed and voltages. I'll give you my latest stable settings @ 3.8 Ghz, but these will not be stable for everyone as each chip may have different imperfections.

Advanced CPU features: All enabled, Turbo Boost disabled (to ensure optimal stability).
QPI Link Speed: x36 [gives me 7.2 Ghz]
Uncore Frequency: x17 [3400 Mhz = 2x+1]
BCLK frequency: 200 mhz
System Memory Mulitplier: x8 [1600Mhz = rated speed]
DRAM timings: 9-9-9-27 [rated timings]

LLC: Level 1
Vcore: Normal
DVID: +0.16875 [1.27v vcore at load]
QPI/VTT: 1.260v
CPU PLL: 1.600v
IOH core: 1.12v [single GTX 570, factory oc]
DRAM voltage: 1.64 [rated voltage at above specs]

**Note: my vcore is actually~0.030v higher than displayed in BIOS
**Note: my VTT is actually ~0.035v higher than displayed in BIOS as measured by multimeter.
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My thoughts on speeds:

Picking your CPU frequency to meet your needs is of utmost importance. If you are looking at my guide, chances are that you are thinking about the power draw and/or heat of your CPU. I picked a nice 3.8 Ghz (50% oc), which will provide me with solid 24/7 use without doing rapid damage to the CPU. You may only want 3.6 or you may want to go to 4.0 Ghz. If you are going past 4.0 Ghz, it may be a touch harder with all power saving features enabled. Still, think about what clock speed you can actually use/need and not just the highest possible.

Picking your DRAM speed and timings is very crucial with your thoughts of stability and power saving. Benchmarks vs real world performance show that 1333 Mhz CAS 9 should be your minimum target. After that, real world performance diminishes so quickly that it's not even funny. Going past 1600 Mhz CAS 9 equivalent doesn't provide any real benefit. Buying memory rated at 1333 Mhz CAS 9 or higher will make your experience great. Choosing to overclock past you memory's ratings may cause stability issues and will require higher voltages/temps. My thought is why go for a high memory overclock if it has stability/temp issues for almost no performance gain.

I really want to just stress the picking your DRAM speed and timings as a critical part to achieving lower temps/voltages/power consumption and better stability overall! It may be tempting to get the besting timings & speed possible, but don't do it unless you are hardcore into overclocking for bragging rights. Note: picking lower timings & slower memory speed is better for gaming, where picking higher speeds and higher timings is better for things like photoshop and video editing... but it' will barely make any difference anyways.

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Now that you've picked the speeds you wish to achieve for both DRAM and CPU, it's time to actually overclock! Start off with a voltage profile and BCLK + multiplier that sits in a 'usually stable for everyone else' range.

Step 1: Splitting your DRAM from CPU.
This method may cause more or less work than overclocking both at once. Still, I like this method as it's good to know that it's NOT your RAM holding you back.
1) --- Set your SPD multi as low as it will go and turn down your uncore by the required amount. Set your CAS timings at the rated speed or +1 to ensure 100% stable RAM (provided your chips aren't defective).
2) --- Set your BCLK and CPU multiplier to achieve as close to your CPU clock speed as possible. Using your highest Multiplier will usually require more voltage than using a slightly lower multiplier. You will find that one specific multiplier will be your 'sweet spot' for voltages (more on this later). For mine, I found that 19x worked best (tired as low as x17). If you aren't using the max multiplier, I suggest you turn OFF turbo-boost as we are going for lowest possible voltages.
3) --- Set your starting voltage profile.
4) --- Boot into windows and start stress testing. See if you can pass 10 minutes, if you pass [or fail due to overheating], then your voltages can probably be reduced. Back to BIOS!
5) --- Lower your DVID and QPI/VTT. Some people will say to lower one at a time, but I found I was able to lower both at once. Don't drop it by too much, just a couple steps at a time. Also, know which BSOD error means too little VTT vs Vcore (ending in 124 means too little QPI/VTT).
7) --- Continue to repeat steps 4 & 5 until you cannot pass step 4 or get BSOD.
8) --- Increase DVID or QPI/VTT depending on which one is casing instability. NOTE: only change one voltage at a time now! Test until stable again.
9) --- See if you can lower the opposite of what you increased in step 8. Testing for stability (with ~10m stress testing).
10) --- If you started with a high IOH core, now you can start testing it at lower voltages for stability.
11) --- Now we have the lowest voltages we can get... but they probably aren't stable. After this point, you'll need to do longer runs at stress testing and will probably have to increase one or both voltages by one or two steps. See the section on stress testing for more information. If you just want to find something stable quickly, you can just increase both QPI/VTT and DVID by a tiny bit right now and that will probably cut a day off stress testing. Move on to DRAM before doing full stability testing.

Step 2: Clocking your DRAM
It's time to move on to getting your DRAM back to the speed that you want!
1) Increase the SPD multiplier to obtain (approximately) the speed you want your RAM to operate at. Increase the uncore frequency to be 2x or 2x+1 of the SPD (I suggest 2x+1 in most cases).
2) Set your timings based on what you picked for them to operate at. USE EXPERT!
3) Make sure you have the proper QPI/VTT and DRAM voltages set for your speeds/timings.
4) Boot into windows and try 10 minutes of stress testing on your CPU. Make sure it passes as you may need more QPI/VTT now that you increased the speed/timing of your DRAM.
5) Increase QPI/VTT as needed.
6) Stress test your RAM. If your version of windows has a built in memory diagnostic tool, run that as it works great and is already installed. To access it, you need to hold down the "DEL" key when BIOS is passing off to windows. You'll get a funny looking screen with some options to test your memory. Start off with a simple test setting to speed things up and look for any 'gaping' flaws in your settings.
7) If everything passes to this point, then stress test the HELL out of your memory. Pick the worst setting and multiple passes. This should end up taking a minimum of 2 hours, possibly 3-4 hours and if it all passes, your RAM is probably stable (stability can never be guaranteed, 2-4 hours might be 90% certain where 8+ hours means 98% certain). RAM doesn't seem to require as lengthy of stress testing as CPUs, but you may wish to go longer, especially if you fold!!!

Before final stress testing:

So, we now have very low voltages, full power saving features enabled, (most likely) stable RAM, and an overclocked CPU! The reason why we were only doing short stress tests is to pick out any major problems and really speed up the process. you can spend weeks finding the perfect settings, so it's nice to be able to cut some corners when you don't need perfect settings. Now we will need to test for final stability and find final voltages/settings. Sometimes you can stress test for 3 hours before fatal errors show up, so it's very important to have a feel for where your voltages/temps are before getting into heavy stress testing.

If your temps are already pushing your comfort level and voltages are as low as they can go, you will want to reduce your o/c or play around with BCLK vs CPU Multiplier to find more optimal settings. No point running a 3 hour stress test when you're 90% sure that it will overheat. Also, if you think that your voltages will be too low and cause instability after 3 hours, nudge them up slightly so you can skip that first fail after 3 hours.

Last edited by draemn; February 17, 2011 at 12:40 PM.
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