Odd Observation re Barton 2500+

[jmichna]

The following may help someone out:

I happened to acquire an unlocked Barton 2500+ some months back. I originally had it in my main PC, but ... having replaced it with a Barton 3000+ @ 2340mHz... I put the old 2500+ in my daughter's PC.

Trying to overclock, I noticed that I really couldn't get past 2083mHz with this particular CPU (and it really wasn't stable at that speed), no matter how much I up'ed the vCORE. Cooling is not the issue (I'm using a ThermalRight SLK900A HS/92mm fan... temps remained in the mid-30's... even at 100% CPU output... SETI@home). The mobo is an EPoX 8K5A2+... good overclocker board.

I tried an experiment and dropped the vCORE back to default (1.65v) and, lo and behold... the CPU is stable!

For some reason, any voltage increase just killed overclocking... but returing to default voltage worked (she's running right now at 12.0 x 171mHz... can't get 13.0 X 167 to work... sheesshhh).

I hope this might help someone out.

[Dooin' it]

Good info.......(the kind of stuff people rarely post back about so good to know).

FWIW, I usually step up on speeds/bus ***before*** playing w/ voltage as I try to get away with the lowest common denominator before changing too many things at once. Though, I know most of the o/c folks take voltage as a heavily weighted variable. I'm no o/c guru so my luck in processes are simply due to *basic* and innocent intentions.

Now, where do I put all this freon????

[Upgrader1]

I have a 2500+ barton and can OC to a 3200+ by changing FSB to 200 in BIOS. This is with the V-Core @ 1.65 V. I tried the 13x166 and couldn't get there. I have found that the most stable setting for this chip was to leave the FSB alone and set the multiplier @ 12.5 x 166 which gives 2.075 Ghz with no rise in Temp. This also was with leaving V-Core @ 1.65 V. I also changed the memory from the PC2700 to HyperX PC3000 that runs @ 370 Mhz. When changing to the 12.5 x 166 the cpu should read @ 2800+ . Temp range was the same as what it ran @ 2500+ (47C ~49C) where as when changing to 3200+ speeds it ran (56C ~ 58C) Also you should leave V-Core alone unless you start running unstable and even then I wouldn't change V-Core over 1.75 V

[jmichna]

Originally posted by Upgrader1
I have a 2500+ barton and can OC to a 3200+ by changing FSB to 200 in BIOS...

Unfortunately, the motherboard used in my situation (EPoX 8K5A2+) is a Via KT333 chipset... 200FSB means the PCI slots are at 40mHz, and some of my h/w components don't like that. I know some folks who run KT333 boards at and above 200mHz, but I've also got a RAID-0 array that gets flakey when bus speed gets too high.

I have experimented with all different combinations of multiplier, FSB, vCore... this particular chip is not a great overclocker... and adding vCore does make it unstable.

The intent of my post was to call attention to the possibility that sometimes NOT over-volting may help an overclock situation, and is one more thing to keep under consideration.

[Upgrader1]

So I take it that you can at least clock @ 2800+ speeds on said EPox. ... Which is still a good clock speed of 2.083 Ghz. I also know that all 2500+ Bartons are not equal. I have one of the earlier chips that seem to OC well. I use the K7N2 Delta and hve had good luck w/both the 333fsb and the 400fsb. I have found that changing the FSB down around 394 to 398 helped stablize things a bit. I beleive this could be that my memory runs @ 370Mhz. Either that or its the luck of the draw on that Barton Chip. Then again I never had to raise the voltage over the defualt setting.

[unknown9]

I bought a Barton 2500+ AMD late last year. How do I know if my CPU came unlocked? I checked my bios, and it gives me the option to change my multiplier from 11.0 to upwards. But I'm not sure if it would actually work. I didn't want to try it just yet incase I screwed something royal. Should I try to change the multiplier from 11.0 to 11.5 ? Could that cause serious heat or other problems?

Thanks,
Unknownguy

[jmichna]

Originally posted by unknown9
I bought a Barton 2500+ AMD late last year. How do I know if my CPU came unlocked? I checked my bios, and it gives me the option to change my multiplier from 11.0 to upwards. But I'm not sure if it would actually work. I didn't want to try it just yet incase I screwed something royal. Should I try to change the multiplier from 11.0 to 11.5 ? Could that cause serious heat or other problems?

Thanks,
Unknownguy

Did you happen to look at and record the stepping code printed on the label? The Bartons were unlocked until Week 41 (some say Week 43) of last year.

My EPoX mobos' BIOS has a 'fail safe' setting that restores the multiplier and clock speed to the previousd working setting in the event I do something stupid and exceed my PC's capability. You may have that feature.

Even if you don't, it is a relatively simple procedure to reset BIOS to default settings if your OC doesn't work. Just disconnect the power cord from the wall socket, remove the CMOS battery for a few minutes, replace the battery, plug the power cord back in, and boot into BIOS and set things where you want them.

Changing the multiplier from 11.0 to 11.5 will boost CPU speed by 83mHz (assuming 166 FSB) or 100mHz (assuming 200 FSB)... this is fairly modest and should not cause you any issues.

[unknown9]

Alrighty, well I suppose I'll try raising it to 11.5 and see what happens

Wish me luck !