AMD Optimal BIOS settings + Overclocking Guide

JMke writes "Here's a step by step guide on how to get the most out of your AMD setup. Overclocking tips and BIOS tweak settings discussed, as well as an overview of the more popular overclocking tools. Start your overclocking here!" Lots of good info here for getting the last bit of performance out of your system while also watching out for dangers that could fry your processor.

Comments

Temperature

[DrEldarion]

From the article: NEVER LET IT GET ABOVE 55C IN MY OPINION ON AIRCOOLING

When I had the stock heatsink/fan on my 1800+, it would IDLE at over 55C, and peak at around 63C under a full load. I never had any problems. Are overclocked CPUs more sensitive to heat, or is this just a "to be safe" recommendation? AMD says they're good up to 85C.

Re:Temperature

[IvyMike]

The chips are tested at a DIE temperature of 85C. However, the temperature sensor on you MB isn't at the die, it's at the packaging (or maybe just near the packaging), so it's not going to read as hot. A rule of thumb I've read is a 20 degrees difference, so that would mean 65C.

Unfortunately, this is all academic because motherboard temperature sensors are notoriously non-calibrated, and I've seen them be 10C off or more! It's more useful to use MB sensors to monitor relative changes than absolute temperature. (In other words, the difference between temperatures running at idle and at load is probably accurate...but the absolute values are probably fuzzy).

Additionally, the fact that the chip was tested at 85C doesn't mean that it will be harmed by temperatures over 85C; it just means it's likely to not work (a bit won't flip somewhere on the chip). Your system will eventually lock up if this is happening. They used to test some chips at 95C or more, and military use chips get tested even higher, so that shows that the silicon chip itself won't be damaged at those temps...it's just functionality that will suffer. :)

If your chip is marginal, running for long times at higher temps can cause it to die quickly (atom migration, etc, can be more pronounced at higher temps) so some people will warn of running at very high temperatures. But this is very unlikely, and if it does eventually happen, hey...now you need to upgrade. Sweet.

Re:Temperature

[Ella the Cat]

I'm underclocking! My 1400 Athlon Tbird (so 2001) segfaults unless I underclock at 1.3 GHz, but it is then rock solid stable, running at just under 75C at 100% CPU with an external temp sensor. I just wanted a =quiet= PC is all.

Re:Temperature

[MyFourthAccount]

Are overclocked CPUs more sensitive to heat, or is this just a "to be safe" recommendation? AMD says they're good up to 85C.

Overclocking is all about temperature.

So long as you don't mess with the Vcore, overclocking does not make a CPU more sensitive to heat. It just will get hotter. If you can keep the temperature of the die under control by dissapating the extra generated heat, there's no problem with overclocking, but it's instrumental that you have accurate temp readings.

I'm only familiar with Intel CPUs and they have an on-die temp sensor which generally is fairly accurate. The embedded CPUs I work with are rated up to 100C and generally work fine up to that temperature. I wouldn't want to run it continuously at that temperature for a very long time though.

Overclocking may result in a loss in stability but that generally doesn't mean you are about to damage the CPU (so long as the temp is not out of spec), it is more likely related to timing issues.

Now increasing the Vcore sounds like a very bad idea to me. I'm not an EE by education, but I would think that you could seriously shorten the lifespan of the CPU by doing this.

btw. What I don't understand in the "NEVER LET IT GET ABOVE 55C IN MY OPINION ON AIRCOOLING, OR 42C USING WATERCOOLING." statement is why the hell would it be depending on what type of cooling is used? This implies that they are not talking about die temperature, because for the die 55C is 55C, doesn't matter how it got there...

Overclocking

[Ianoo]

The biggest thing I've always found with overclocking (both Intel & AMD) is that 'YMMV' (your mileage may vary). I've talked to people who say they run their systems at 20% more speed than they should be doing, yet one of my systems constantly locks up even if midly overclocked. Increasingly I wonder, given the current prices for this kind of technology, whether overclocking is a bit pointless. Do I spend $100 extra or do I spend 12 hours mucking with my BIOS? You decide!

Overclocking also seems so 1990s now, most people I speak to who rate themselves equal to my own geekdom are in to case modding and quiet PCs... concepts which I find much more interesting than getting 5% extra FPS in Quake.

Re:Overclocking

[Ianoo]

The point is though, that if I spend $500 on a (ficticious) 2GHz processor and $100 on cooling so I can run it at 2.1GHz, does it really make sense to do this when the 2.1GHz processor is available with a crappy (but adequate) fan for $550?

Re:Overclocking

[obsidianpreacher]

But ... but ... but ... it's QUAKE! I simply HAFTA play at 400 frames per second! Have you tried playing it at any less? It's practically a slideshow!

Re:Overclocking

[gl4ss]

the current pricing of cpus however would indicate that your hypothetic 2.1ghz would cost 800$.

AMD Duron 1600 MHz, 64 KB 50.7 e
AMD Athlon XP B 2800+ 2.08G/333 MHz, 512 KB 156.0 e

(some of the disabled cache is re-enableabe on those durons, afaik, and seemingly most do run 2.2ghz+ or even 2.4ghz)

Intel P4 HT 2600 MHz s478 Northwood, 512 KB, 800
boxed 198.2 e

Intel P4 HT 3200 MHz s478 Northwood, 512 KB, 800
boxed 472.5 e

for most though the point is that they can't afford that high end cpu, and for the rest is that they don't want to pay such prices you end up buying for high end cpu(that can't be overclocked in the same ratio as cheapos can). the cooling costs anyways, regardless of if you're going to use it for oc or not(unless you're willing to go with a cheapo, or one that comes with boxed cpus).

hell.. i don't make my buying decisions based on overclockability, i make them on other factors. i just oc them as far as they're willing to go after i've bought them(well, i got one underclocked machine too, as nat-box).

Re:Overclocking

[imnoteddy]

'YMMV' (your mileage may vary)

This is true. The way to understand the YMMV factor has to start by understanding how integrated circuits (chips) are made. They are produced on wafers - flat, round thin slabs of (usually) silcon - typically 200 millimeters (mm) or in some cases 300 mm in diameter. The wires and transistors are created during dozens of steps that involve exposure to light, vapor deposition, chemical etching, and other processes. Many steps involve heating and cooling the wafer.

So why is there variation among chips? Because the process cannot be controlled perfectly, though the manufacturers try really hard. For example, chips on the edge of the wafer will cool off faster than chips in the middle. There are so many variables to control that some will be off. Twenty percent variation is very common, and designers often do simulations based on that amount of variation.

People design chips to a given clock rate, then test to see what they get. A simple example is the Power PC (PPC) that IBM makes and Apple markets as the G5. Apple sells systems that run at 1.6, 1.8, amd 2.0 GHz, but all PPCs come from the same design. The chip in a 1.6 GHz G5 may run at 1.79999999 GHz if given the chance, but it also might fail at 1.61 GHz. Some chips might test out at 2.2 GHz, but probably not enough to sell.

Not so fast...

[EmCeeHawking]

while also watching out for dangers that could fry your processor.

With all of the offshore outsourcing going on, we geeks need as much practice frying things as possible. =)

Re:Fry?

[Scottaroo]

Tom's Harware loves doing stunts like this. They've run processors without coolers just to see what happens, and they investigated problems with the early AMD thermal diodes. Check it out

Re:Anyone Not Know This?

[spektr]

Seriously who doesn't know how to set there BIOS's settings?

My 96 year old grandmother uttered the other day that she was not perfectly confident with setting the DRAM burst timings on her nforce2 board. I pointed her to this site and now she is happy, because she could squeeze 2 fps more out of her box and can thereby delay the "necessary" upgrade for another 3 months. Silly old granny and the fps madness...

And remember guys..

[Lussarn]

No overclocking is considered rock solid before you have compiled a complete gentoo on your OC CPU.

Am I the only one who UNDERCLOCKS?

[MarcQuadra]

I for one don't need the horsepower of a top-end CPU. I have a KT266a-based board (max FSB=133/266) and I put an Athlon-xp 2500/333 into it.

My CPU is underclocked from 1.83G to 1.46G, it dissipates about 45W, which is about the same as a G4, and HALF what a modern P4 drops. It's stable as all hell and I'm very happy with the speed.

I do the same thing to my G3/450, I use it as a fileserver so the 450MHz is totally wasted. I turned it down to 300MHz with less than 2% 'real world' performance difference from the client machines. It also generates less heat and uses less power now.

Any of you living on your own and paying electric bills would be well-served by underclocking, as the VAST majority of our CPU cycles go to waste anyway.

The biggest performance difference you can make?

[Moderation abuser]

The disc is the slowest point, add plenty of RAM as buffer, but nothing makes up for having a fast disc.

15,000 rpm, 3.6ms access time, 8Mb onboard buffer. And an HBA to match.

I find it ironic that people buy cheap systems with slow discs, slow network and insufficient RAM and then try to make it faster by overclocking the CPU.

Re:Fry?

[futuresheep]

Pan fried is an excellent way to cook your processor. After 24 hours in buttermilk, lightly coat it with some chili powder, granualted garlic and onion, a nice coating of flour, then into a cast iron skillet with a quarter inch of crisco at 325 degrees. About 10 minutes on each side, depending on the size of the CPU die should make for a tender and tasty meal. I like some mashed potatoes and gravy, and coleslaw on the side, with a pilsner to wash it all down.