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Asus A7V Overclocking Confirmed
Posted by
CmdrTaco
on Fri Jul 21, 2000 10:08 AM
from the milking-every-last-clock-cycle dept.
from the milking-every-last-clock-cycle dept.
NoWhere Man writes: "It seems that a few Asus A7V Socket A motherboards have reached the market despite AMD destroying the hopes and dreams of overclockers everywhere. A&I Computer has a few boards and has been able to reach 857Mhz. Buyoverclocked.com also got a few, and overclocked to 900Mhz, a picture of the switches is here.
For those interested in overclocking the Thunderbird, Tweak Town seems to have found a way to remove the cpu mulitiplier lock"
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Asus A7V Overclocking Confirmed
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Kinda preachy... (Score:3)
Electromigration is the only thing that can cause physical damage to the chips besides frying it due to overvoltage. But they both end up doing about the same thing to your chips.
You don't know what you're talking about. I have a running 6 and 7 year experiment with electromigration, and guess what? This hasn't been a problem, period. I have a 486/66 and a Pentium 100, bother overclocked, that have been running overclocked the respective times, 24/7, barring power outages. The motherboards are about the only thing in them that hasn't failed. The fans went, the drive (in the P100) failed, the CDROMs long since died, the floppies died, but the CPU's keep on mackin'. The power consumption is to the point where it almost equaled the cost of the machine, but, it's an experiment to see if the CPU (will ever) fail. That and they make nice servers.
Electromigration is something that while well documented in theory, I have yet to see cause a problem. One of my electrical engineering professors has a old transistor collection, and you can see a decay in Beta (B) of these devices, so the gain characteristics have changed a fair bit. This is _much_ more of a problem in a analog transistor, where the preformance is supposed to be linear. In a CPU, the transistors are acting as switches - and as long as they switch, everything is fine.
Heat failure is completely different. Heat goes up, resistance goes up, circuit goes to hell, and the magic smoke comes out. This is what happens when the chips fail due to overvoltage - you physically burned out the circuit. THIS IS NOT ELECTROMIGRATION!
Anyway, that is an explanation of what happens when overclocking goes bad. There's a few white lies in there, but without spending weeks explaining electrical theory and physics to you, it's the best way to explain it. :)
You don't need weeks of physics and theory. If you overclock, you up the clock rate of a CMOS process. Power consumption goes up correspondingly. More clocks, more power, more heat. Too much heat, you burn it out. Better chips can handle more current, thusly running cooler, and therefore be able to run faster. Your watch is CMOS too; It can run for years because it's clock rate is 1Hz.
The problem is that you now have less energy available to generate those higher frequencies.. the clock signals are weaker. Of course, this results in instability and other problems (retransmits, blah blah blah). The solution is that if you want it to run at that higher frequency, you gotta increase the voltage to boost the signal... and take the chance of frying your chip.
This doesn't make any sense. See above comments. Right now, I mildly overclock my athlon. There's nothing that even comes close to making it run slow, so I'll overclock it heavily when games catch up. I suspect this is what most people do.
Re:How can you tell? (Score:4)
I know Michael Dell is a little egocentric, and a lot of people seem to think the world revolves around money and profits, but..
How the hell does Dell's stock price dictate the stability of tectonic plates?!?!?
Re:..but Why?? (Score:3)
A cmos circuit is composed of complementary pairs of mos transistors (hence the name cmos). A mos transistor works more or less like a switch. A voltage on the gate pin allows a current to flow on between the other two pins (transistors have 3 pins). The gate of a mos transistor looks like a little capacitor. You need to charge up the capacitor to turn on the transistor. The output of each cmos gate has two mos transistors, one goes to the supply (about 2 volts), and the other goes to ground (zero volts). The gate turns on one (and only one) of the transistors to select a binary output level. If both transistors were on a short circuit would occur.
There are three sources of power consumption in a cmos circuit. (1) leakage currents (very small), (2) charging and discharging the gate capacitors, and (3) so called "class A current."
The first item, leakage, is very very small. Several orders of magnitude smaller than the other two. It is independent of operating frequency.
The second item on the list, charging/discharging current, is quite important. It takes a fixed amount of energy to charge the gate capacitor and force the transistor to change state. At higher clock rates you change state more often. Since power is simply energy per unit time, the power consumed from these charging currents is linear with respect to operating frequency. Double the frequency, double the power consumption. BTW, you can force the capacitor to charge more quickly if you increase the supply voltage. Sometimes this is necessary for overclocking. Higher voltages will lead to higher power dissipation (though not necessarily increased current (for a given frequency)).
The last item, "class A current" is caused when both transistors in a cmos output are on at the same time. Since the transistorgates have small capacitors, they can't turn on and off instantaneously. Therefore, when the gate changes state, there will be a short period where both transistors are partially on. This overlapping conduction causes a sizeable current to flow; a short circuit of sorts. This is the so called "class A current." The exact magnitude of this current is dependent on the particulars of the transistor design and the clocking waveforms. It's hard to say what happens to class A current as clock rates go up except that power consumption increases.
BTW, in the process of dumbing down something that isn't all that complicated to begin with you said some pretty silly things:
Electromigration is the only thing that can cause physical damage to the chips besides frying it due to overvoltage.
Heat, static, current, etc. Electromigration pales in comparison to soldering irons, drills, and other tools of the trade.
as those gates expand, they start passing more current
MOS has a negative tempco (unlike BJTs). They conduct LESS current when they are hot. That's why you don't need to worry about thermal runaway when playing with power mosfets.
More current = more heat
No. P = IV, you know that.
Now the more current that is passing, the more likely it is to "jump" the gate
WTF?
without spending weeks explaining
Doesn't take weeks. Cmos is pretty simple.
Current is what causes heat, NOT voltage.
No. See above.
Your processor is not a resistor. It's not that simple.
a (slight) increase in heat production due to the higher frequencies
Large increase. Greater than linear.
..but Why?? (Score:3)
But is the performance gain really worth it? If you need those few extra clock cycles every second, why are you cheaping out and then risking not only your warranty (or blowing it altogether) but the life of your CPU? If I really wanted some extra speed in my brand-new machine, I'd spend the extra $200 or so, not blow time, energy, and then my entire investment by overclocking.
Please - teach me. I am but your sponge.
There's a reason they locked it... (Score:3)
AMD put the clock multiplier lock on their CPUs to prevent this; if you bought a Thunderbird that was supposed to be 866MHz overclocked from 800, for example, then used it in a benchmark between it and a Pentium III 866, the Pentium would win and AMD would look bad, even thoguh a genuine 866 may have beat the Intel chip (MAYBE)
The same thing happens with modems now. A 56K modem is actually a "Mo", in that it modulates but receives data digitally over the phone line. THat's why the send speeds are less than the receive speeds. and most cheap computers come with a 56K/14.4 modem, i.e. 14.4 modem without analog converter for downstream. It's a ripoff and people don't understand that. If the CPU had the same problem, there would be chaos.
By the way, I'm not entirely sure how a 56K modem works in terms of downstream/upstream and every detail of how it's different, but that's the basic idea.
So maybe you could get a little more juice out of your processor, it should be your choice. But many hardware vendors are not trustworthy enough (since it yielded soooo much profit) so the clock multiplier locks should be obeyed, IMHO.
I hope I'm not responding to a troll... (Score:3)
1. Reputable retail outlets will not resell returned, potentially defective merchandise as new. They will return the product to the original manufacturer. The bulk of the major retailers fall into this catagory (compusa, cdw, necx, pcwarehouse, etc) as do many smaller places. If you are buying from a place that is not reputable, you have a lot more problems to worry about than overclockers.
2. Overclocking is safe and easy these days. AMD and especially Intel underclock some chips for purely nontechnical reasons. You might as well see what your CPU can really do.
3. Your reasoning here:
is outright wrong. I'm not going to justify this statement here because it would go offtopic, but it should be obvious.4. As someone who runs unattended servers year round, 3 lockups a year is not unusual. You're going to have problems with hard disk failures, CPU and case fan failures, spontaneous memory failures caused by atmospheric raditation, as well as misc. cabling and environmental-related failures. I'm also assuming that you have a quality UPS. I would not consider a machine that locked up for mysterious reasons 3 times a year suspiciously unstable.
Please help keep overclocking an option for intelligent enthusiasts.
-OT
Socket-A Multplier Lock Status (Score:3)
There is even a rumor going around about an Athlon 2 in the future, which will be an unlocked Tbird (nevermind the fact that they still seem to be unlocked so far), and that AMD will be working with AMI and Award to make BIOSes that will help prevent the remarking of AMD CPUs by displaying the true original CPU speed alongside the overclocked speed (e.g., "AMD Duron 600 @ 800MHz").
Why overclocking is EVIL and must be stopped. (Score:3)
(2) Once it fails, these people may return their CPU to the store as "defective".
(3) The store, rightfully never trusting the word of consumers, will test the CPU.
(4) The store's test is short and in a nice cool optimal climate controlled environment. And subtle problems that show up when the CPU is warm and been running for a long time will not appear on the test.
(5) The CPU goes back into the glass case to be resold.
(6) You (after saving up a long time): "Hi, I want to buy that CPU right there."
(7) You are now on a trip through hell. Your CPU may fail later that day (if you're lucky), or next week, or "lock up" only 3 times per year. You cannot now run your unattended server on your DSL/Cablemodem line. Your system is forever unstable.
(8) By the time you realize the true cause of the problem, the warranty/exchange period is long gone.
(9) You are screwed. And it is the fault of overclockers.
I don't want to hear about how "most" overclockers are responsible, blah blah. One person getting screwed on a machine that takes years for him to finally save up for is one screwing too many.
Overclocking needs to be blocked by the CPU itself, where it can't be circumvented. Just as laws are set up to occasionally let many a guilty man walk free rather than wrongfully convict so much as one innocent person.
Overclocking must end for the good of the consumer.