Rod, at 04:57 on Jun 26 1996, you wrote to Bill Grimsley...

BG> The first batch of these CPUs was suffixed ADZ, and there were no
BG> problems running them with a 40MHz bus (i.e. CPU speed of 160MHz),
BG> whilst some reports from internet newsgroups had them running as
BG> fast as 50MHz/200MHz.  The later models, however, were suffixed
BG> ADW, and would flatly refuse to run at anything above their rated
BG> CPU speed of 133MHz, under any circumstances.

RS> Odd that they reversed the lettering sequence. Mine in an ADZ.

Might just be an in-house date code or similar.  You were lucky to get an
ADZ though, as yours will overclock just fine.

RS> Which newsgroups specifically ?

Dunno, Randall and Russell are the 2 involved here, not me.

BG> Given that AMD's 5x86-P90/160 was imminent at the time,
BG> it was suggested that AMD had intentionally put a brick
BG> wall in their 5x86, to prevent people from buying the cheaper
BG> 133 and running it at 160 (just as we're doing right now).

RS> Well, its certainly doable. Corse its also quite possible that they
RS> just made a change for other reasons and it had that effect too.

Sure, anything is possible, but it does seem rather strange that the only
observable difference is that the later version won't overclock.  I'm not
suggesting that it was intentional, just that it wouldn't surprise me.

BG> Mine was the first one purchased, back in early April,
BG> and it ran a treat at 160MHz, but by the time Russell
BG> and Randall bought theirs several weeks later, the deed
BG> had been done, and they would no longer run overclocked.

RS> I got an ADZ last week.

So did Randall, but it was the last one in stock.  All others were ADWs.

BG> Needless to say, they were both ADW suffixes, and once
BG> we had theorised about what AMD may or may not have done
BG> to their CPUs, it was by then a simple matter of changing
BG> them for ADZs, and now everybody is happy again.

RS> Dont believe if, its like a drug, they wont be happy for long |-)

True.  Is yours running overclocked, BTW?  :)

BG> Although we have no specific proof that the later CPUs have been
BG> crippled to prevent overclocking, it still sure looks that way to us.

RS> Dunno, I have heard that so often and have seen the particular cpu actually
RS> used at the higher speed later that I'll wait and see on the theory. There
RS> have been similar storys about some of the pentiums lately too.

Given the limited life of a CPU these days, it's hard to imagine that
they'd bother, but nothing would surprise me these days.

BG> These CPUs are now selling for a fucking incredible $89 inc tax, BTW.

RS> Yeah, sure cant complain about the price, or the price of the motherboard
RS> either.

At under $200 all up, it looks like 486 technology ain't quite dead yet.

RS> What are you doing motherboard chipset wise ?

Had to buy a later board, as the Soyo wouldn't run the AMD as a quadrupler.
 The current one uses a SIS chipset (which I don't mind at all), with an
AMI WinBIOS (which I happen to think are pieces of shit).  The Award is the
current pick of BIOS chips at the moment, IMO.

Regards, Bill
@EOT:

--- MsgedSQ/2 3.30