Subject: Re: Different speed CPUs show up as same speed
To: None <rmk@rmkhome.com>
From: Ken Seefried <ken@seefried.com>
List: tech-smp
Date: 06/14/2002 00:44:40
Rick Kelly writes:
> Perry E. Metzger said:
>
>>Yes there is. The locking protocols on the two processors are not
>>guaranteed to have compatible bugs if the processors aren't the same
>>stepping. I'm pretty surprised that this is working for him --
>>everything I know for x86 says if you do SMP, you need identical
>>processor steppings.
>
> Sequent got away with it on their 386 boxes, but the 486 machines did
> use uniform processor speeds, as I remember.
>
AFAIK...the Sequents were closely coupled SMP on a given board (and always
had the same CPU speeds on a given board), but between boards it was a
loosely coupled MP affair. Thus it was easier to have boards of different
speeds, as stepping issues, etc., didn't come into play.
Of course, I could be wrong...
Anyone with really good memory remember if the Balances had different CPU
speeds?
Ken