I have a A7V and with the new price cuts on AMD’s, I was thinking of upgrading my Tbird form a 900 @ 1gig to 1.3gig. My questions are.
Will a 1.3 even work in my A7V or will it just run at a lower speed?
What’s the fastest CPU an A7V can take?
Do the multipliers go past 12.5?
How far dose an average 1.3 gig overclock?
Will I be able to overclock a 1.3 on my A7V?
Thx & Cya
<font color=green>Paranoia is just a higher awareness of reality.</font color=green>
A7V should work at 133 MHz FSB, but thats it. FSB overclocking is over as far as A7V is concerned. A7V133 also has the same limitation with onboard switches, but its circumvented with jumperfree mode and you can select higher frequencies with BIOS. you can select 1 MHz FSB increments in Jumperfree mode with A7V too, see whether it allows FSBs past 133.
as far as multiplier is concerned, the highest one 12.5 with 133 MHz FSB would give 1663 MHz, quite enough i guess. 12.5 is the highest multiplier you can get, which might increase with faster processors. basically there a 4 bit code for the multiplier on 4 CPU pins, 5 is lowest which wont be used anymore, so AMD might make it 6 or 7 so that a multiplier of 13~14 could be accomodated.
i wonder whether the A7V133 BIOS will work on A7V to get the jumperfree mode.
other method to overclock the FSB is to change the crystal, which is quite risky since you may kill the board hence I wont recommend it.
<font color=blue>die-hard fans don't have heat-sinks!</font color=blue>
Yeah, it's the same question all right. But it's not as simple as the FSB clock rate. I believe the critical factor is the clock multiplier. Look at it this way: I have a 1.2 GHz C-type CPU, this means it has a hard-wired multipler selector (courtesy of the AMD factory) of 9. If I had a 1.3 GHz C-type, it would have a multiplier of 10. Now, I put my chip in my A7V133, and the board automatically recognizes the chip as requiring the 9x. It uses 9x even if I set the FSB to 100, in fact 100 is the default for POST in the jumper-free mode. So the computer POSTs at 900 MHz on the CPU, loads the 133 setting from the BIOS, then switches to 1200 MHz but still using 9x as the multiplier. I do not know what would happen if I attempted to change the multiplier from within the BIOS, e.g. to use 10x instead of 9x. In theory, if I wanted to I could use 12x and leave the FSB at 100, and this would work with this chip -- the problem is, I don't know if it's possible to just override the CPUs factory multiplier with a BIOS setting, or whether a mod to the chip is required, see what I'm saying?
So now turning back to your situation, if you get at 1.3 B type with at 13x multiplier, there is first the question, what does the BIOS think about that and report, since supposedly the BIOS is limited to 12.5x on this board? Does it just barf and refuse to boot? Can you override the 13x with a BIOS setting (without making a chip mod like the above hypothetical) to force it to run 12X or even 12.5x? If so, then you're golden, set it to 12.5x and run at 100 MHz and you will get 1250 out of that 1.3 GHz chip.
I would be very interested to know the answer to two questions:
1. What does the BIOS see or do when confronted with a factory multiplier beyond its documented range?
2. Is it possible to override the multiplier through the BIOS setting alone?
For example, suppose the answer to the first question is, it won't POST, then you're screwed and it doesn't matter what the answer to the second question is. Or suppose the answer to the first question is it uses higher multiplier, or uses the maximum multiplier of 12.5x, then you're all set. Or suppose the answer to the first question is something strange, like it bit-wraps and thinks 13x looks like, say,
4x. Now the answer to the second question about manually setting the multiplier becomes relevant.
Or you can just say what the heck and go for the 1.2 that you know will work.