Typically, processor manufacturers are conservative when rating the clock frequency of their microprocessors. A processor which can successfully operate at 2GHz, for example, may be only rated at 1.5GHz for a variety of market reasons.
Unfortunately, since most processors can be clocked at frequencies significantly greater than the rated (marked) clock frequencies, unscrupulous resellers and/or distributors can remark inexpensive processors at higher frequencies – a procedure known as ‘over-clocking’ – and then sell the processors for resale at higher prices.
And this can cause some problems. According to Intel, a common problem of over-clocking relates to bit errors and data corruption. Usually, chipsets and/or hardware components which need the system clock frequency for computing operations may incorrectly interpret electrical signals between ‘1’ and ‘0’ due to timing violations.
More serious problems of over-clocking relate to advanced chipsets which use a random number generator (RNG) for security applications such as cryptography, digital signatures, and protected communication protocols. If the host processor is over-clocked, the statistically random and non-deterministic numbers from the RNG of the chipsets may no longer be random, and the security applications may be severely compromised, Intel says.
Now, the company has patented a new mechanism that promises to halt the practise of over-clocking entirely.
The mechanism comprises a detection circuit (which detects over-clocking of a clock signal based on a reference signal) and a prevention circuit (which prevents over-clocking of the clock signal). This is achieved by either disabling the computer system or reducing the performance of the computer system in response to the detection of the over-clocking of the clock signal.
The Intel US patent – 6,535,988 – filed way back in September 29, 1999 – was granted on March 18 2003.
You can read it <a href=’http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1=6,535,988.WKU.&OS=PN/6,535,988&RS=PN/6,535,988′>here</a>.