Because the motherboard I am messing with does not have built in overclocking features, I am having to use a wire mod to increase the VCore on a Barton 2500+ CPU to get it to 2.3 to 2.4 GHz, and because the stock VCore is 1.65, my only real option with a wire mod gives me 1.85... some of you I know have played with the wire mod thing changing bus speed, VCore and multiplier... I have done this several times... and this CPU is now modded to 200 bus, 11.5 multiplier, and 1.85 VCore.
On a side note, I just blew out the PSU running 3DMark03 today, though... Computer powered down with smoke coming from the PSU... actually the first time that has happened to me... I hope everything in OK... It was a cheap 420W psu that shipped with a new case. I knew better, but I wanted to get that cpu set up for my friend. Shopping for a psu on newegg as I type.
I have very good Thurmalright air cooling (SI-97A) on this Barton with a nice 80mm high speed fan, and I plan to keep the cpu below, say, 54C on a rare hot day twice a year in the summer when at full load, but at around 40 to 45c most of the time most of the year...
This is for a friend's computer... I am just worried about the high VCore... but unless I want to run it at stock, there is not much else I can do. People seem to be a mixed lot about the max volts on a CPU... I have been running my Mobile Barton at 1.82 for over two years now with no problems... but is 1.85 too much? And before the PSU failure, it was toggeling from 1.85 to 1.87 and freaking me out. I assume that with a new quality PSU, it would settle in at around 1.85. But is that too high? It is a budget gaming computer, so it the cpu dies after two years because of the high voltage, then that is fine... but I would like it to last longer than a few months...
"When you over-volt your CPU, you should normally be careful of how much you do. 1.65V to 1.7V should not be an issue with an Athlon XP mobile, and even 1.80V should not dramatically reduce CPU life. However, over-volts of 1.85V and above will likely reduce the life of your CPU, with the risk of a very quick death."
So how often can a Barton 2500+ have the bus changed from 166 to 200 and run fine with the stock 1.65 VCore? I just assumed it would need 1.75 or 1.775 or so to run at 2.2GHz. The motherboard does support a +5% or some such setting. That might get me to 1.725 VCore... HHmmmm that is the smart thing to attempt.... drop the multiplier back to the stock 11x and be content with 2.2GHz if it is stable...
Maybe there will be options to reduce the multiplier and runn it at 200x10 or something as well... I hate the trial and error process with the wire mods... every time you take the cpu out, there is a chance of #ucking it up...
That is more akin to the answer I was looking for... besides, that lame motherboard will more likely only offer a +1% to +3% to VCore after I get the new PSU in there... if the PSU smoking up did no perminent damage to other crap... If the VCore is already set to 1.85, perhaps I should throw caution to the wind and set the multiplier to 12x
Good news here... the motherboard actually supports a +10% to VCore, and althought it ended up being less than 10%, it gives me a 1.76 to 1.77 reading, and the cpu at 200x11.5 or 2.3GHz has been rock solid with no crashes.
My T'bred 2200+ needs a 1.8vcore in order to break 2180mhz, if it helps, but it puts out quite a substantial amount of heat, though it is just as stable with the increased Vcore and speed as it is at stock (just passing on some experience, it may help you). Mine was actually fluctuating above what it was supposed to (running at around 1.82 rather than 1.8) than below.
The only thing I would say about overclocking the Barton core is that in my experience the core become less tolerant of overclocking over a long period of time. I had a Barton running at 12x200 for about 18 months before it started to exhibit issues.
I swapped out memory and several other items not thinking that the CPU could be showing some signs of stress. In the end, after trying a new CPU in the same rig ( the new CPU worked fine at 2.4 again ), I backed the original CPU down to 11x190 (2090). And now it is fine again. This CPU has been running in a machine since April 2004, mostly on 24hrs a day, running seti@home, gaming and office apps.
Also from my experience anything over 55 degrees centigrade caused issues with my Barton. Good, solid and reliable cooling is a must. And don't be fooled by idle temps, once the Barton gets flying it gets HOT.
Now for anyone who says that this proves that overclocking reduces the lifespan of a CPU please remember that even at 2090Mhz this machine is still "well" overclocked and I have been absolutely amazed by the Barton Core. I have two budget work horse machines using these and they are still great PC's even after the passing of the Socket A.
FSB is overclocked to 200 by a wire in the cpu socket as well... as for the bios, yes, there is an option to go up, but there is no divider, and pci, agp go up as well... However, pushing the FSB up to 205 might work out just fine, and I will give that a try after this computer has proved itself over some time at its current settings... my friend is very happy to have it running at 2.3 GHz, and I am very happy to have the VCore to only 1.77
I too am amazed at the Barton. I have been running my 2500+ Barton mobile at 11x200FSB=2200MHz at stock VCORE for almost three years of 24/7 operation without any issues. Recently, instead of another upgrade I decided to see if I could push it any farther to get just a little more life out if it. I increased the multiplier to 12 and it runs stable at 2400MHz and 40 Deg C at idle. I only had to bump the VCORE up to 1.6V. I started to run some stress tests, but discovered that the +12V rail on my cheapo Ultra PSU was pulled down to 10.8V. Needless to say, I have ordered a new Antec supply, and will continue overclocking after it is installed. Still, I am very encouraged so far.