What is the significance of a 'stepping code'?

petrolhead2003

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I have no idea what this is,could anyone enlighten me?

And what is a good/bad stepping code for A64 chips?



<P ID="edit"><FONT SIZE=-1><EM>Edited by petrolhead2003 on 01/17/05 04:06 PM.</EM></FONT></P>
 

fishmahn

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From what I know, a stepping code is a slight internal revision to the CPU. It's still (for example) a P4E Prescott, but they rearranged a few things, or laid a wire somewhere different, or maybe used aluminum instead of gold for something, or something else like that, to make it different, slightly, from a previous or future stepping code.

Each processor type has better/worse stepping codes, and I don't know what's good and what's not.

Mike.
 

jihiggs

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i think stepping codes usually include the date the cpu was made, maybe the fab it was made it, but mostly they tell you how close to the center of the silicon wafter the chip was.

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old_fart_again

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fishmahn has it about right. Steppings are minor changes to the device.
A stepping could be a shrunk version - to increase dies per wafer and thus reduce the cost per die (die is the silicon part of the device).
It could be to fix some errata (see the manufacturers web pages for lists of errata)
It could be to raise the performance,usually clock speed, of the average die on a wafer.
It might be to reduce power consumption.
It might not even be visible to the customer.
etc.
So, if you are an OC'r or care about power/heat, you would usually want to get the latest stepping. It would usually have the best overclocking capability and lowest power consumption.


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petrolhead2003

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I intend to enlighten myself by clocking my Sempron3100 upto 2.4 ghz.
Will this be enough wusy?

Or have i got to go for >2.5ghz?

Now,with my new Asus K8N NF3-250.
First things.
Lock the pci/agp.
knock my ddr speed down to 333 and ramp up the fsb to 250.
ddr will be 409-should be ok.That'll be 2250 cpu.
If all's ok.
Change ddr initial speed to 266,and up fsb to 270.
cpu=2430ghz,ddr at 374mhz.
possibly upping cpu voltage to 1.5(1.4 standard).

Is it really that easy?
my ddr400 is only vdata,generic/non performance stuff,so i don't intend on upping it's speed by much.

http://www.xbitlabs.com/articles/cpu/print/sempron-3100-oc.html
 

NEQX

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Stepping codes on CPUs are important for mostly people who want to add the 2nd cpu to their existing system.

If you originally bought the system with both physical processors in place, you do not have to worry about it. But if you are planning on adding the 2nd processor sometime in the future, you need to note the stepping code to match the one you already have. If you don't know what it is, you can go back to where you bought the original cpu from and tell them that you want to add the 2nd cpu. They'd give you something matching what you have. In some cases, you do not need to have the exact stepping number but a set of alternative stepping codes could be compatible...

In some cases stepping numbers indicate a newer, more energy efficient processors ie; newer generation.