Over-clocking X58 with Power Saving enabled
My first experience at CPU overclocking was a lot of learning and fun. I thought I'd share my experience of doing a 50% overclock with the power-saving features enabled. See my system specs if you want to know, otherwise I'll just say that I'm using a i7-930.
Post 1: Understanding BIOS settings
Post 2: Overclocking and clock speeds
Post 3: Testing for stability
Background to important X58 settings:
CPU clock ratio: For locked chips, you can set this as high as the max turbo boost frequency when you have turbo boost enabled and as low as x12.
CPU C1E state: Basic power saving mode that 'stops' clocks when idle, little to no performance hit.
C3/C6/C7 Sate: These modes increase power saving, but may have a small performance impact when your CPU goes from idle to busy (should have no impact while under load).
CPU thermal Monitor: *I think* this one lets your CPU drop voltages to protect thermals. May impact performance if your voltages/cooling is sloppy.
CPU EIST Function: Lowers your multiplier when idle (or light loads), reducing your overall frequency/power consumption. Has no impact on performance under load.
Bi-Direction PROCHOT: Allows for monitoring thermals and assertion of throttling commands such as CPU thermal monitor.
QPI Link Speed: A saturated QPI for quad cores is around 7.5-8 Ghz. Knowing this, you can change the multiplier to a lower value as you increase BCLK to stay under the limit of your board.
Uncore Frequency: Usually most stable if it's 2*(system memory multiplier)+1, but don't always need the +1.
BCLK Frequency: This is the main method of overclocking X58. Some boards can go as high as 224, but all decent boards will easily get 200 Mhz. This times your multiplier gets your frequency.
System Memory Multiplier (SPD): This times your BCLK gives you your ram speed (i.e. 200x8 = 1600 Mhz).
DRAM Timing Selectable: Always pick EXPERT and change all the channel's timings... won't take that long!
Timings: Unless you are trying to overclock your RAM to hell and back, you only need to change the first 4 timings and can leave the rest at auto.
Load Line Calibration: If you have this option, turn it on! Provides 'cleaner' voltage and is generally considered safe. If your mobo (mine does) has multiple levels, just pick the middle (level 1) mode unless you're pushing past 4 Ghz.
CPU Vcore: Change this to "NORMAL" if you leave power saving features on, otherwise set to a manual number.
Dynamic Voltage DVID: If CPU Vcore is set to normal, use this to increase your vcore. When coupled with power saving features, it will increase the vcore by this amount when your CPU frequency increases. When power saving modes are active, the voltage will not increase by this amount.
QPI/VTT voltage: Wording will change based on manufacture. This voltage is just as important as vcore and extremely important as you overclock your RAM. Should always be at least within 0.5 of your DRAM voltage.
CPU PLL: This provides the voltage that keeps your CPU frequency stable. Most people can lower this to 1.6v with success. If your CPU frequency constantly fluctuates by more than 1 Mhz at load, you may need to increase this.
PCIe voltage: Only extreme overclocks need to adjust this setting, leave at auto*.
QPI PLL: Same as CPU PLL, but for the QPI frequency. Usually leave at auto*.
IOH Core: This voltage may need to be increased based on how many GPUs you have installed (or other power hungry PCIe cards). I found that +0.02 for each GTX 460 1GB gave me stability. You may hear suggestions of 1.16 for 2x GPUs and 1.20 for 3 GPUs... Try to find stability with lower voltages as 1.20v adds up to 10 degrees compared to 1.14v.
ICH I/O: Leave at auto* unless attempting extreme overclock.
ICH core: Leave at auto* unless attempting extreme overclock.
Dram Voltage: Max safe voltage for X58 is 1.65v. Do not increase more than 0.5v above VTT voltage! At your own risk increase past 1.65....
*Note: you may wish to set these manually and should always set these manually for +4.0 Ghz! Leaving at auto may cause problems as you push the limits of your CPU that high... Plus, these other voltages may help stability with a lower vcore.
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.
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
DVID: +0.16875 [1.27v vcore at load]
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.
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.
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.
Testing for Stability:
Now that we have adjusted our voltages/temperatures/speeds/etc to fit a profile that we think has a chance of stability, it's time to realllly test out our system so we can be 99% confident of stability!
The most important thing to remember is that you can never get 100% confidence in stability, and 7 hours should be a minimum for 95% confidence. Also, do not cheat by cooling your computer's room well below ambient. It's okay to try and keep your room close to ambient, but it will not fully test stability for a 7 hour gaming session unless you know that you'll be able to control the room temp in the future. **Remember that we have already tested our RAM for 3+ hours for stability!
1) Pick your favorite tool that stresses your CPU to the max, it's really good to start off with tests that produce extremely high temps!
2) Run at least 4 hours of max temp stressing and pass (modify settings as needed to pass). I suggest running more than one test, so keep the temp stressing to about 4 hours. If you are only going to run this one test on your CPU, then run it for at least 7 hours.
3) Run at least 8 hours of stress testing that is balanced approach and not max heat. Pass or modify until you pass.
4) Optional: Stress test your GPU while stressing your system. I suggest stressing your GPU when running stress tests. Gives you more realistic results and better confidence about stability.
5) Once you Pass stressing your CPU with both types of stress tests @ the required time limits, pat yourself on the back and look at your awesome job!
**NOTE: If you are having lots of problems with stability during these stages, you may wish to re-test your RAM for stability!
The End Result!
Enjoy your power saving overclock! If you're like me, you'll take extreme satisfaction in checking out all the power saving features your overclock offers you! Download CPU-Z and check out:
1) Idle frequency
2) Idle voltages
3) Idle temps
4) Smile at how awesome those are (for saving power/heat)
5) Turn on a stress test or something to load your CPU
6) Watch your CPU instantly kick into the overclock and achieve the clock speeds you set!
7) Be proud of yourself and your overclock.
8) Turn off the load on your CPU and open up something that only has minor CPU usage (i.e. GPU3 F@H client)
9) Be impressed by #1,2,&3 even though your computer is actually using your CPU for daily tasks :D
**It is important to debunk the myth that power saving features are bad when over-clocking! When you are pushing high limits, it will increase difficulty of stability with power saving features enabled, but it is still possible. 99% of the time, the power saving features will NOT degrade performance... the exception being the combination of Bi-Directional PROCHOT and CPU Thermal Monitor, as if your temperatures get too high, they will throttle your CPU. The only performance hit you will ever experience is when going from deep idle to responsive, where you may notice a very short pause as the CPU comes out of deep power saving modes. This will only happen when your CPU has been sitting completely idle for a while. Otherwise you'll notice no performance impact at load and tons of power savings at idle!
I think I'm done! That took a long time to type up! Well over an hour!
Feedback if this interests you?
very nice guide... i will try to use your guide when my system is ready... vey soon... probably this week..
btw you dont need to do quad-posts ;p
I know, but it's much easier for me to break it up into separate posts. I prefer that to a single, very, very, long post. I've tried to make it relatively simple and this isn't intended for pushing your limits on air as will need to start looking at a few voltages/settings that I did not include. Maybe this week coming up I'll try to get 4.3 Ghz with power saving features on. That would sure be interesting!
what kind of mobo and cpu do you overclock?
i'd like to add this to your "voltages" comments
most mobo when raising block will increase voltage in auto mode and most of the time it will end up too high for no reasons.
I would advice anyone to manually set voltage to their default value before starting bumping bclk, and bumping them only when required
For your second point, I'm showing a 'quick and dirty' method that is much faster than what you suggest. That is why the difference.
you're right auto voltage works :D
each mobo handle this differently, some will be more aggresive with voltages on auto, epecially those "built for OC" motherboard. Since they want people to achieve decent clocks without being complicated
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