PDA

View Full Version : What's Clockable And Not?



SurferJoe46
07-06-2007, 07:43 PM
I would like to know if the processors that have no rewritable BIOS are overclockable?

I ask because some years ago I got hit with the W95.CIH.damaged worm, and it was able to rewrite the BIOS to damage it with a payload date thru the clock/calendar.

My imagination hints that not all BIOS's are rewritable and therefore not affect-able either...right?

If we entertain the possibility of BIOS anti-hack programs (such a thing?) out of the equation, then how does a nasty like that get to harm the system anyway? :confused:

So..here's where this really is going...is a processor like the locked-down ones in..say..a Dell beige-tower, clockable?

Can the voltages be changed somewhere to get an O/C in a board/CPU combo like that?

I don't think I want to try it..but I am just curious. :confused:

I can see all sorts of changeable things on the SOYO/AMD..but I am not gonna mess with it.

Graham L
07-06-2007, 07:58 PM
I don't think any PC processor chips have a BIOS. A CPU chip is a CPU chip.

A PC "BIOS" is a memory device containing code for a POST and the BIOS code. It's provided by the motherboard manufacturer (and usually written by a specialist company).

The first IBM PC BIOS chips were mask programmed. It was impossible for users to modify them. Later it was cheaper to use EPROMS (UV erasible) which could be rewritten, but not usually on-board. ;) Even later, it became cheaper to use EPROMS without the quartz window. They were write once.

Now they mostly seem to be EEPROM ... electrically erasible. This is how people are given the opportunity to make a board useless by "flashing the BIOS".

When some naughty people worked out how to change your BIOS without your consent, some manufacturers put two BIOS chips on the board ... so you had a spare copy. Others put a jumper which had to be moved to enable programming the BIOS.

If your computer has a removable (plug in) BIOS chip, you could make a copy of it , make the changes, and programme a new chip.

Is it worth the trouble?

Changing the voltage doesn't change the speed. It alters the power consumption. It can increase or reduce the smoke emissions, which should to be familiar territory for a California man.

SurferJoe46
08-06-2007, 05:51 AM
I don't think any PC processor chips have a BIOS. A CPU chip is a CPU chip.

A PC "BIOS" is a memory device containing code for a POST and the BIOS code. It's provided by the motherboard manufacturer (and usually written by a specialist company).

The first IBM PC BIOS chips were mask programmed. It was impossible for users to modify them. Later it was cheaper to use EPROMS (UV erasible) which could be rewritten, but not usually on-board. ;) Even later, it became cheaper to use EPROMS without the quartz window. They were write once.

Now they mostly seem to be EEPROM ... electrically erasible. This is how people are given the opportunity to make a board useless by "flashing the BIOS".

When some naughty people worked out how to change your BIOS without your consent, some manufacturers put two BIOS chips on the board ... so you had a spare copy. Others put a jumper which had to be moved to enable programming the BIOS.

If your computer has a removable (plug in) BIOS chip, you could make a copy of it , make the changes, and programme a new chip.

Is it worth the trouble?

Changing the voltage doesn't change the speed. It alters the power consumption. It can increase or reduce the smoke emissions, which should to be familiar territory for a California man.

I feel really stoooopid asking these infantile questions, as I guess most everybody here is some sort of gamer and has things tweaked to ultra high speeds and performance.

Those who don't game are just ignoring these sorts of posts anyway.

Me? I'm just interested and would like some basic info.


But I learned something today..the BIOS does not live in the CPU. One point for you and twenty eyeblinks for me.

What are all the voltages and settings I see in my SOYO SmartGuardian...they appear to be addressable and therefor changeable too....I figger they have something to do with O/C'ing..right? The Vcore values are all before me in the control panel and I see that they can be jostled around up or down for whatever reason.

Isn't voltage the tool that is manipulated for clocking? I can't see any physical changes that are allowable, so it has to be some outside source that makes things run faster and hotter.

Since I don't "game", I don't really need lightspeed processing, but as I see it, I could appreciate an improvement for the videos I run...especially going to HDTV and other wide screen processes.

The next consideration is that my SOYO/Athlon XP 1.5+ is getting a little long in the tooth, and I may not be able to find a replacement piece if I need it in the near future. Is now a good time to buy the most obvious parts...like the CPU and other parts that might fail?

I have a really good power supply (Enermax485 watt, dual fan) which has given me NO problems so far..over 4 years of operation.

BTW: Smoke is nature's way of saying: "Don't build houses there".

Graham L
08-06-2007, 05:55 PM
I've just read a "technical" article in an Australian magazine on this subject, so you're not the only one with this misapprehension, Joe.

To change the speed of the CPU you change the clock speed. That's what determines the speed.

However there are reasons to change the supply voltage. The logic gates which do all the work have to have their inputs switched from a high to a low voltage (or vice versa , of course). The inputs have capacitance. To change the voltage on a capacitor requires a current flow. The capacitors are small, so the currents are small. But there are a lot of them.

Now there are a group of interlocking factors involved:
* The faster the transition must be, the greater the current needed.
* To get more current flow, it helps to have a higher supply voltage.
* Higher supply voltage increases the transition voltage levels.
* The more the voltage swing, the more current, thus power, needed to switch.

And:
*The higher the supply voltage, and current, the higher the power input.
*The higher the power input, the more heat to be removed from the silicon to the atmosphere. With 30W, 80W, 120W this is not a trivial problem.
* There is a maximum safe temperature for the internals of the chip.
* The higher the temperature, the shorter the expected life.

With a CPU to have a certain rated clock speed, the manufacturer determines the lowest supply voltage at which the chip will reliably work. Then they do the calculations (and tests) to ensure that the chip can be kept at a reasonable temperature with an "economic" heat exchange system. Allowing the appropriate safety magins, they then market it.

If the enthusiastic overclocker winds the clock speed up, keeping the supply voltage constant, at some point the CPU will work unreliably, or not at all. (You've got some margin, the manufacturer wants to ensure total reliably). The gates just won't switch. The extra current will cause more heating of the chip, but probably the CPU will be unreliable before it smokes.

To keep the CPU operating correctly, it is necessary to increase the supply voltage to increase the switching speed. The power now starts to increase sharply. (W=IxV). That's when better cooling is needed.

So to increase the speed, you increase the clock speed. (Bus speed, multipliers). But the chip won't work reliably at the higher speed without more voltage.

Just increasing the voltage will make it a "hotter "chip. But it won't be faster. It will just be hotter.

trinsic
08-06-2007, 06:21 PM
Most if not all OEM computers (DELL, HP etc.) will have no overlocking ability's by default. There are some where you can flash the BIOS for a more updated one with overclocking features. Ideally you do not want to change voltages as even going up by 1 will blow some up (increments of 0.1 is what I usually see talked about).

When overclocking your computer will reach it's limits sooner or later and start being unstable. Upping the voltage can fix this to get a higher clock or simply become stable :) RAM can also be overclocked in the same way. But problem is some BIOS's lack simple settings like AGP Lock and Memory Dividers (without them you pretty are overlocking everything in the computer which is a nono)

The problem with a lot of motherboards/BIOS's is lack of overclocking features. The best would have to be DFI motherboards as they have every setting you possibly need to get 150% out of your parts.

Any guide around for overclocking will show you up the FSB 5/10mhz at a time checking for stability. Once that stability goes you up the voltage by 0.1 and continue raising the FSB until you have a nice clock. And a note not all CPU's are good overclockers. Same goes for RAM. eg. The older C2D lot of CPU's are better overclockers then the new lot out today.

Quickly typed this so sorry for any errors which people can correct ;)

SurferJoe46
08-06-2007, 07:33 PM
I see this needs a little more input..not that what I read so far isn't terrific. I had a lot of misconceptions and just want to get my thought in line for a decision to make soon....which I am going to read after my fishing trip in a couple of weeks.

But in the meantime, if there's any more comments, I'd appreciate them..thanks in advance.

I will be able to get and send mail when I am gone..but the trout are gonna be primary...!

It looks now like I might be interested in just building a newer system with XP again.

This SOYO SY333 Dragon Ultra Platinum is just fine as it is..but I think I want to play with something new. I haven't had a problem hardware-wise with it yet...so I am not gonna kick it with new internals other than some more RAM.

I've also gotta visit a guitar forum ...TIA