Voltage and Temperatures, Cooling Part 2

I touched some on voltage and temperatures before, and will even after this section, as both are vital. You cannot have your PC without voltage, it will create heat when it has voltage. So one tip with overclocking once you reach your goal is to ensure you're running the lowest voltage possible and be completely stable. Below this section is the stability section to help you ensure you can. The problem with increasing voltage to maintain a stable overclock is the ammount of heat you're creating. And since I touched on case fan/airflow dynamics some, and basic air/fan/heatsink cooling, you should be getting a good idea of what you will need to do in order to enjoy the performance of your PC overclocked with no worries. Or that's what I'm hoping for at this point.

There are programs out there that read voltages, I personally use Everest for voltage readouts, it is fairly accurate and easy to work with. But you will want to monitor voltages, especially vCore voltage. There is a common issue on Intel Spec motherboards for running their processors that is called vDroop. vDroop comes in two parts, the first the drop in voltage from set parameter (reads 1.29v when set to 1.32v for example), the second is the difference in voltage between an idling CPU and load stressed CPU (reads 1.29 idle and 1.26 load when set to 1.32 in BIOS, for example). AMD supporting boards do not have this issue as noticable as Intel. This can create instability with overclocks if that voltage is just below the point of stability under load, and there are "mods" one can do to their boards to alleviate this, but this article will not dive into that subject, just Google your motherboard with mods or vDroop mods at the end. This could cause you to increase your voltage a step or two up and while you will now be stable, you will also be running quite a bit warmer. Keep an eye on it. Same goes for anything which you increase the voltage of, the North Bridge, South Bridge, GPU, CPU, RAM, GDDR Memory, etc. Also, better quality Power Supply Units will be more efficient and stable at producing power, which can help greatly if you notice voltages changing a lot, as lower quality PSU's are the cause of many problems, crashes, failed/RMA'd equipment. I was once using a cheap $20 500W PSU, one of the cooling fans seized (it was 6 months old!), and the unit overheated and the capacitors started leaking fluid, luckily it missed my motherboard, and did not damage my video card (but was a pain to clean!) because the system shut off once the capacators gave out. It does pay in the long run to pay a little more now and save a lot later, just remember that when building a PC.

Voltage increase is also an enemy to components because the more voltage you add to the circuits, the quicker they will degrade. This is a known affect of circiutry and voltage, and there's nothing to stop it from happening, but if you are careful with increasing your voltage and not just setting them all on the highest level, you will have a good PC for years and not have to worry. But every increase of voltage you do in BIOS, the lower the life expectency of circutry/components becomes. Those who upgrade every 6 months or so may have no issues running max volts, adding more via Volt Mods because it's no big deal to them if that component lasts, but if you want a good OC'd dependable PC for years to come until you're ready to upgrade, then please increase voltage carefully, if you increase a lot, please do it for OC/Stability reasons for short term until you find your lowest voltage settings for your overclock.

Just do yourself a favor and have a piece of paper or notepad handy, write some of your settings down, so you can use them for reference. Besides physically writing down can help when you're not quite sure what you had set before, as nobody has a perfect memory, it does help to have a reference to go back to. And verify that the voltages you are using to maintain your Overclocked PC is within safe temperature boundries, and are as low and stable as possible.


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Stability, and How Exactly do I Know I'm Stable?

Stability is easy to verify. First off, if your PC reboots itself or you get the dreaded BSOD (Blue Screen Of Death), your pc crashes/errors, you have an issue. This may not necessarily be hardware/component related, could be OS or Software also, but genrally it's a good mix of all of them or improper settings, overheating. Below are some steps you can take to verify temperatures, that your PC is capable of taking heavly stress loads without faulting, and give you peace of mind that you built your PC right, have proper airflow, and have a good overclock that you can run without issues.

I recommend using Prime95 or Orthos for CPU Stressing, out of those two I use Orthos (can stress dual cores quite well). Just open and click start, let it run for as long as you can bear to be away from your PC. The longer the better, but if you can successfully pass 6-8 hours, you're generally considered stable. When using Orthos, set it to Small FFT's (CPU Only), and set the Priority Tab to 9. I'd say if you can pass 24 hours, you're very stable. This will give you load temperatures, so you can test your cooling. If the test fails, then you need to make more adjustments in BIOS. Generally when the CPU stress fails you are not giving your CPU enough power to get the job done. That's when you need to decide whether to downclock your CPU or increase your voltage, when the time comes to make certain decisions, be as prepared as you can be.

There's also stress tests for graphics, which is very handy when overclocking your video card. Which can be very tricky or very easy depending on the card and how easy the MFG decided to make it. If you get artifacts, then increase voltage if possible, or downlcock a few MHZ until there is no longer any artifacting on the screen (glitches, yellow pixels, etc). On AGP it helps to increase the AGPv and AGP Bus by a couple of MHZ, but on PCIe there has been no result to show proof enough to increase the PCIe Bus Speed from 100, some do it for stability and that is okay, but stay below 120MHZ to avoid SATA and other issues, or at least this has been the popular rule for a while between many professionals. Many have increased the PCIe Bus to 130+ and been able to enjoy the benefits from it, but this is not well documented as of yet, and until I can provide you with more solid information, I still recommend staying below 120MHz to avoid any problems, keep checking back to see if I've updated to verify this. Increasing PCIe Voltages has also not shown much for stability since there's already extra power being fed to the card (at least mid-level to higher end cards that suck down more than 75W that the PCIe bus provides) to compensate when the GPU is under load.

--Side note on PCI-e Bus Speeds:

I have been able to contact a few people who've increased their PCI-e bus speeds beyond the popularly recommended max 120. Two of them were using IDE drives and were able to use full 150MHz PCI-e bus speeds with no issues, and were able to attain what they claimed as better overclocks on their video cards. Another person whom is known and respected on TPU (D44ve), was using SATA HDD(s), an 8800GTS, ASUS Striker Extreme M/B and attained better performance and had great stability using 145MHz PCI-e Bus Speed. Remember that the people I talked to had newer components, which could be the difference, especially with video adapters. Thus far it's been NVidia's newer 8XXX Series cards. Newer video cards may be able to use the increased Bus Speed more efficiently than the first wave or two of PCI-e based graphics cards. But this does shine a light on an overlooked performance increase for many building/using new or newer systems. If anyone that reads this has been fortunate in their experiences with increasing PCI-e bus speeds beyond 120MHz and had no issues, please contact me, give me all the information you can as I want the most valid information I can attain before I can safely recommend whether or not increasing beyond 120MHz is worth it.

Another important stress test to perform is memory stability. I recommend Memtest, either the boot-DOS version or version for Windows OS. Allow this to run as long as possible again, the more passes the better verifacation. If you have an error, this can be more complicated, This could be tied with undervoltage, incorrect timings, malfunctioning DIMM Slot or a bad chip on the RAM Stick. If you are getting BSOD's and crashing issues that cannot be explained this is a good place to start since RAM is a strongpoint for information transfer in your system. Do not overlook this when overclocking or you will pay the price. Also, it is helpful to read up on timings, the different settings/variables and meanings of the memory timings, it get's complicated so it's recommended to learn the basic timings, as they help with stability, bandwidth (throughput), latency (response), and overall system performance.

There are many different programs and methods for testing and verifying stability, the ones I listed I personally use and so do many others. Some Intel users have the benefit of using a program called Intel TAT, it will stress the CPU higher than any other program out there, there is no other way you could stress your CPU as much. Some argue that since you get your load to 100% you are, but check your temps, and remember what that 100% load is doing, your CPU can 100% load on easier tasks, TAT uses harder and more stressing tasks to perform a severe stress. Use at your own risk!

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Bottleneck? What is that and why should I care?

This can be the cause of much unexpected anger from many individuals who believe they understand overclocking and it's performance benefits but do not reap the entire rewards for their hard work and efforts. Bottleneck is just as the word says it is, take a beer bottle (like a Budwieser bottle for instance), and at the top it's narrow, at the base it's wide. Now to implement this into your PC, you have massive ammounts of information transactions being made, some busses are wider than others, some have to share, but they all have to travel through some of the same "intersections" to get to where they're going. This is where having good quality componenets can reap serious rewards for those who pay attantion to this. When stock, sure speeds are slower, which in turns lowers scores in tests/benchmarks, and as speed's increased scores increase. Fair enough. But when you see someone with a similar system as you with something slightly different, such as a different processor (let's say a newer processor) getting higher scores even though you're overclocked close to that person, that newer processor (try P4 Netburst vs. Core2Duo) is much more efficient and making more transactions than your "older" processor. To match the performance you would have to overclock substantial ammounts that watercooling may not even be able to handle.

All systems have bottlenecks, it's part of how motherboards and components are designed. Imagine hauling ass down a highway, to your job in the morning in the city, you hit a downtown intersection, you have 1000's of others trying to do the same as you, but due to an older inefficent intersection design and only few lanes to spread out on this is considered a bottleneck situation (i.e.gridlock, slow moving traffic, stuttering, slowing down). The best way to alleviate this is with newer equipment such as motherboards, cpu's, even RAM that's faster and can attain tighter timings per clock cycle and process information more effieciently by design.A lot of people are still using the AGP graphics interface, and as such the video graphics mfg's are still releasing some new stuff their way. But depending on just how "old" that system is, they may see less performance as compared to a newer AGP based system. Such as an older 2.4 Pentium 4 Socket 478 system with DDR1 2700 with AGP 4x as compared to a newer dual core Pentium 920 Socket 775 system with DDR2 5300 with AGP 8x. There will be only so much either system can do to provide as-far-as bandwidth for the video card, which will take as much as it can get. The more that can be provided, the better performance the card will display.

Bottlenecking can give user's serious headaches, but a few simple tests such as 3dMark06/05/03 and even Aquamark 3 can give a good idea of bottlenecking, since generally when referring to bottlenecking people refer to Video Graphics Adapters. Run a 3dMark of your choice and go online and compare it to similar systems, you'll be able to see what others have scored with similar and slightly different and very different setups, it's a good reference point that many miss or misunderstand. And one of the easiest ways to alleviate bottlenecking is to overclock system bus speeds, memory speeds, cpu speeds, gpu speeds, etc., even on new systems this helps a lot performance wise. So do not get yourself down if you have an older system (and if it's capable of OC-ing) and your gaming isn't what you expected, you may need to overclock your system to attain better performance.