whats limiting my overclock? (barton 2500+)

[apac]

The system boots up at 11x200 at 1.75v but prime95 always fails in under a minute.

Specs are:

Abit KV7 kt600 mobo
zalman AL/CU HSF @normal fan speed
2x512 corsair select cas 2.5 memory, default settings
CPU is <50C under load

 

[OnEMoReTrY]

Originally posted by: apac
The system boots up at 11x200 at 7.5v but prime95 always fails in under a minute.

7.5 volts huh? Be careful not to stare into the center of that thing.

 

[apac]

Whoops. Typo .

 

[xbassman]

You probably need to give it more voltage.
I have 3 Barton 2500+s and only 1 of them hits 11x200 (@1.775v)

 

[Toro 45]

Could be your H/S if it's the Zalman CNPS7000A-AlCu cooler it doesn't look like it's designed so much for overclocking as it is for quiet operation. You said you have your fan at normal fan speed,have you tried turning it all the way up while running Prime?

 

[someone16]

Mobo? Sure the AGP/PCI set to 66/33?

 

[charloscarlies]

Originally posted by: xbassman
You probably need to give it more voltage.
I have 3 Barton 2500+s and only 1 of them hits 11x200 (@1.775v)

 

[apac]

Originally posted by: charloscarlies

Originally posted by: xbassman
You probably need to give it more voltage.
I have 3 Barton 2500+s and only 1 of them hits 11x200 (@1.775v)

Hits, or is stable at? I can easily hit that FSB but prime95 fails.

edit- just ran prime95 at 190 FSB overnight and it apparently failed after an hour.

 

[WA261]

I would bet on vdimm and vcore voltages.

 

[Concillian]

This is a desktop 2500+ I assume?

Yeah, your CPU is limiting. More voltage and more cooling. The desktop 2500+ is just not a given at 2200. Older ones from before when there were mobiles were much more likely to reach 2200 without issue. I have an unlocked 2500+ that will do 2300+, and a more recent (locked) 2500+ that isn't even stable at 190 FSB and 1.75 volts.

At 190 I wouldn't be surprised if your mobo were causing problems, as I recall the KT600 has no AGP/PCI lock. Unless you can set the ratio such that it will underclock the AGP/PCI busses, I think some boards allowed that.

 

[apac]

Originally posted by: Concillian
This is a desktop 2500+ I assume?

Yeah, your CPU is limiting. More voltage and more cooling. The desktop 2500+ is just not a given at 2200. Older ones from before when there were mobiles were much more likely to reach 2200 without issue. I have an unlocked 2500+ that will do 2300+, and a more recent (locked) 2500+ that isn't even stable at 190 FSB and 1.75 volts.

At 190 I wouldn't be surprised if your mobo were causing problems, as I recall the KT600 has no AGP/PCI lock. Unless you can set the ratio such that it will underclock the AGP/PCI busses, I think some boards allowed that.

There is a ratio. I have it set at 6:2:1 FSB/AGP/PCI. I actually kicked it up to 1.8v and my CPU is at ~49C load with 200FSB but it still craps out in prime95. It seems to stay cool enough that it should be stable, so I don't think that's the issue.

 

[WobbleWobble]

I also think it's your CPU.

I've played with a couple desktop 2500+ and none of them were able to hit 2.2GHz and pass Prime95 regardless of the voltage.

I drop in a mobile and bam, I'm able to hit 2.4GHz and pass Prime95

 

[imported_bbomb]

Mine wont even hit 167. Piece of crap. :|

 

[dwcal]

I must've gotten lucky. I have a desktop Barton 2500+ that runs 2.2Ghz at stock voltage and even with the retail heatsink (although I have a SLK900U now). Good thing too because my cheap m/b has no voltage adjustments. If your temp is <50C and your memory is PC3200, the problem isn't cooling or RAM, but you can try running with one stick of RAM. I have one 512 stick of the same Corsair value select as you. I did get Prime95 errors when I combined it with a 256MB stick of generic RAM with Micron chips.