Re: Clarifications about AMD TLB L3 bug

The little lost angel <a?n?g?e?l@[EMAIL PROTECTED]
> wrote in
part:
> <rbmyersusa@[EMAIL PROTECTED]
> wrote:
>>What's the difference between this and Intel's botched
>>FDIV bug?  Very, very simple.  At the time of the FDIV
>>bug, x86 was for "peecees," and no one cared if Intel made
>>mistakes that IBM (or DEC or Sun) never would.  Now they do.
> 
> Actually, I think the real difference between the two is that
> nobody saw it was a mistake Intel couldn't recover from. However
> for AMD, this would look like a killing blow on top of the
> underwhelming performance against competition for a new product
> generation. While I vaguely remember outcry against Intel for
> that bug, I don't remember anybody saying that it's going to
> sink Intel. There just wasn't sufficient competition capacity
> to takeover a company with over 90% of the market share. Thus
> the difference in perceived impact.

In addition to this very valid commercial argument, there is also a
fundamental difference between this AMD "bug" and the Intel FDIV bug:
the AMD bug might slow machines a bit under unusual cir***stances.
The Intel FDIV bug gave erronious results in a few cases.
People worry _far_ more about data corruption than machine speed.  
The FDIV bug might well have sunk AMD.  This will not.

Actually, I find the continued harping on the AMD bug interesting
in and of itself.  No-one complains of things they don't consider
a threat.  AMD must be considered a serious threat. I'm not sure
why:  AMD milked past superiour performance into higher ASPs
which Intel first was happy to follow, then started to undercut
to recover market share.

I believe actual performance is increasingly hard to measure.
MHz hasn't cut it for a long time.  Intel has focussed on
bandwidth and cache.  AMD has worked on latency.  As a result,
each processor excels at some tasks and is only mediocre
at others.  There is no one "best" CPU.

-- Robert