Barton multiplier unlock

[Marc1957]

Can the Barton 2500 go over the 12.5 x multiplier ? It seems that I could do it with the Abit NF7-S and not with the A7N8X : correct ?

 

[kylebisme]

i turned mine up to 13 on my gigabyte 7vaxp, didn't have to unlock it or anything.

 

[AnAndAustin]

Barton like all TbredB should be completely unlocked. What it does depend upon is the mobo NOT the CPU. It's all to do with the 5th FID bit which AMD introduced to cope with mults above 12.5x. Many mobos can't understand this 5th FID bit and that will limit them to adjusting between 5.5x and 12.5x on a CPU iin that range by default and may appear locked if a CPU uses a mult higher than 12.5x by default, although you can cut the 5th FID bit to drop the CPU back in to the lower mult table.

So YES Barton XP2500+ will be able to go over 12.5x IF the mobo can do it, b ut VERY few can. TheSnowman I thought GIGa 7VA* used switches on the mobo to adjust the FSB (actually PCI divider really) and multiplier speeds ... with only 4 switches how can you select a 13x mult? If the CPU is below 13x the 5th FID doesn't even exist on the CPU does it?

 

[johncar]

AnAndAustin wrote,
>If the CPU is below 13x the 5th FID doesn't even exist on the CPU does it? End quote.

Just a minor correction. Palominos/Tbreds/Bartons are all "5 bit" Multiplier Code CPUs. And even though some speed grades have Multipliers less than 13X, the 5th bit/signal circuit "does exist" in all of them...it just happens to be set LO by default when less than 13X.

But, as you say, the problem is that many mobos are unable to toggle that 5th signal circuit.
John C.

 

[kylebisme]

Originally posted by: AnAndAustin TheSnowman I thought GIGa 7VA* used switches on the mobo to adjust the FSB (actually PCI divider really) and multiplier speeds ... with only 4 switches how can you select a 13x mult? If the CPU is below 13x the 5th FID doesn't even exist on the CPU does it?

6 switches for the multipier so i get everything from 5x to 18x.

 

[pspada]

I just put a Barton 2500+ into my FIC AN19E, where the SPD automatically set the FSB to 166. It ran at the 166/333 speed for 5 or 6 hours with no problem, then the system rebooted, and it will not boot, even to dos (divide mulitplier crash) with the FSB set to 166. So I had to manually lower the FSB to 133/266, and then up the multiplier to 15x manually. So it is now running at 2000Mhz, acting as a 2600+, with a FSB of 266. The multiplier adjust is in the bios, not on the board.

Interesting? Oh, BTW, FIC makes the motherboard for Epox, so this m/b is an exact copy of the KT400 Epox m/b.

 

[kylebisme]

i'll bet your ram cannot take 333mhz pspada.

 

[pspada]

Originally posted by: TheSnowman
i'll bet your ram cannot take 333mhz pspada.

It's PC3200, and runs at 400Mhz CAS 2. So

a) how could it run fine for 5 or 6 hours at 333Mhz?
b) run now and previously at 400Mhz?

I suspect the BIOS does not really handle the 333Mhz properly. I'm going to borrow a NForce2 board and try the processor in it, and if it works correctly, then I know its the m/b or KT400 chipset. If not, then I RMA it. But understand that I think its a good value even considering that I'm running the FSB at 266, because I've set the multiplier to 15x, and it's running at 2004Mhz. I'll play with the multiplier to see if I can increase that without problems.

 

[kylebisme]

ahh if it ran good at 400mhz i would have to say i made a bad guess. ya maybe it was just the motherboard being funny, either that or the chip is just defective and can't take the fsb which would be odd too.

 

[pspada]

Yea, remember it ran fine at 166/333 for 5 or 6 hours, then started rebooting. I figure either some component on the board died, or perhaps the processor went funky. I'll update ya once I've tried the chip in a NForce2 m/b.

 

[Jeff7181]

There's an issue between nForce2 dual channel RAM and GF4 cards... does that apply to you maybe?

 

[pspada]

I do indeed have a GF4 Ti4600, but this AN19E uses the KT400 chipset, so it's not an issue now. I'll find out if it is when I get the NF2 m/b, and report back to that post. If so, I'll not be upgrading until they fix the issue, 'cause I sure as hell am not upgrading my video card yet again so soon.