Many new overclockers leave our user forums never to return when they ask "How do I overclock?" and receive “Raise the FSB or HT clock” as an answer. But once you're armed with the lingo, the principles are fairly easy to understand. Let's cover a couple of the basics.
Frequency
A processor is made up of a complicated series of microscopic electronic switches (transistors) on a pulsating power circuit. The number of pulses (power cycles) per second is called the circuit's “frequency.” It takes at least one cycle for the transistor to change state between on (1) or off (0), and the ones and zeros become part of a data stream.
Modern central processors run at thousands of millions (billions) of cycles per second, or gigahertz. This is the same range of frequencies at which microwaves and mobile phones operate, so that a relatively short piece of wire can become a fairly good radio antenna. Preventing cross-communication between circuits, where one circuit acts as a transmitter an the other an unintended receiver, is extremely important.
The conductors on motherboards, called traces, are much longer than those of an integrated circuit, such as a central processor (CPU) or graphics processor (GPU). In order to reduce noise, signal loss and cross-talk, the pathways that connect various processors must run at slower frequencies.
The CPU Multiplier
As the need for increased data speed outstripped the ability of various busses to support it, companies developed a variety of methods to send more than one bit of data per conductor, per cycle. These methods include double data rate used in memory modules, quad data rate used by Intel’s front side bus (FSB), AMD’s HyperTransport (HT) interconnect, and Intel’s recent QuickPath Interconnect (QPI).
Because Intel’s most recent FSB uses quad data rate technology, its clock frequency is a quarter of its data frequency. That is to say, the clock rate of FSB-1333 is 333 MHz (megahertz, or millions of cycles per second). The CPU itself relies on an actual electrical frequency (the clock rate) to set its internal speed, so a CPU multiplier of 10x on an FSB clock rate of 333 MHz (FSB-1333) results in a CPU frequency of 3,333 MHz, or 3.33 GHz.
AMD’s internal HT link uses a 200 MHz clock speed with data rates of five to ten times clock speed, resulting in 1,000 to 2,000 transfers per second. But since HyperTransport supports full bandwidth in both directions at the same time, AMD doubles its name to HT 2,000 (1,000 MHz data rate, 200 MHz clock rate) and HT 4,000 (2,000 MHz data rate, 200 MHz clock rate). The most important thing to remember when overclocking is that both HT 4,000 and HT 2,000 use a clock rate of 200 MHz, so that a CPU multiplier of 10x would provide a CPU clock speed of 2,000 MHz, or 2.0 GHz.
Though we won’t use an Intel QPI-based system today, users should know that it operates in a similar fashion to AMD’s HT link, but at a slower 133 MHz base clock frequency.
Voltage
Frequent overclockers will discuss BIOS settings such as VCore (voltage of the CPU core), VDIMM (memory voltage), and various data pathway/memory controller voltage settings under a variety of different initializations. Some of these will be discussed in detail as we encounter them in BIOS screen shots.
- Why Overclock?
- Understanding The Lingo
- Getting Started, The Hardware
- Keeping It Cool
- More Shared Hardware
- Overclocking AMD's Phenom II X2 550
- Phenom II X2 550 O/C Performance And Efficiency
- Overclocking AMD's Phenom II X4 955
- Phenom II X4 955 O/C Performance And Efficiency
- Overclocking Intel's Pentium E5200
- Pentium E5200 O/C Performance And Efficiency
- Overclocking Intel's Core 2 Quad Q8200
- Core 2 Quad Q8200 O/C Performance And Efficiency
- Recommendations
It's all a game of averages. Tom's Hardware hasn't accidently killed a processor by overclocking it in a while, though I'm sure a couple editors have intentionally done so to find the voltage limit. The problem is, once again, you can only look at averages.
3 months continuous use at 1.45 volts caused an E8500 to lose its OC stability. It had to be clocked down to become stable again, and lost much of its voltage tolerance. It wasn't destroyed however.
1.40 volts should be significantly safer than 1.45 volts, but until a few people report on how long their cores lasted at 1.40 volts its impossible to tell "how much safer", that is, how much longer it will last. All that's known is that it should last "significantly" longer, but whether that's 4 months (33% longer) or 30 months (10x longer) is the unanswerable question.
I would have liked to see combined charts as a conclusion but that's a minor criticism.
I'm just wondering what the 'next-gen' E5200 (i.e. the intel people's OC'er) will turn out to be? Some flavor of i5 I assume, but who knows.
"Intel’s value-priced Core 2 Quad Q8200 uses two of the same processor dice as the Pentium E5200....."
I don't know why you choose the Q8200 it's a notoriously bad overclocking chip, if you wanted a budget Intel Quad core that had room for overclocking you should have bought the Q6700/Q6600.
MSI P45 Diamond is not LGA1366, but LGA775. LGA1366 is for Core i7 processors only, LGA1156 is for Core i5 and i7 (only dual channel DDR3-1333/1066). LGA775 is the old socket, for Celeron D, Celeron 4xx, Pentium Dual Core, Pentium 4, Core 2 Duo, Core 2 Quad.
Otherwise, pretty good article. Though perhaps a better choice for the Intel quad would have been a 9550...I thought they were under $250 by now. Same time, I guess the Q8200 does seem to be a more difficult overclocker...Intel may have intended this to be the case so as not to gut sales of their Q9000 series. And readers may as well know before jumping on a Q8200 thinking it'll overclock like an E5200.
PS: Synthetic benchmarks should be outlawed until they fairly and accurately give an indication of real-world performance
Even so, you must have a dud, since Q8200 should overclock much more then what was achieved for the purpose of the article.
E5200 is indeed the "new Celeron". A very good cheap chip, if you get it to at least 3.33GHz (1066 FSB + 1066 DDR2). I totally agree with this choice.
But why did you go with DDR3? It's double the price of DDR2. In real life, if I have to choose between screaming-fast DDR3, or double the amount of that in DDR2... my personal preference is more RAM, even if slower RAM.
So Q9550 + DDR2 could make the list, at least price-wise. With a little OC, it would be the king of this... let's call it roundup. Some may argue that the 955BE is, but I have my favorites.
You got lucky.
1.45v is the ABSOLUTE MAX voltage for 45nm.
1.5v is the ABSOLUTE MAX for 65nm
Absolute Max is defined as "the point where actual damage to the CPU can occur."
For more info: http://www.overclock.net/intel-cpus/374005-45nm-vcore-discussion.html