[Info-vax] Alpha Personal Workstation question

[Keith Parris]

On 8/9/2012 5:10 PM, Michael Kraemer wrote:
> Well, considering all the fuss back then about the Alpha being a
> 64-bit CPU and thus superior to all others, it would have been
> a much better marketing argument if already entry systems
> would have allowed to use RAM in excess of 4GB.

I recall Alpha being promoted because it had the fastest clock rate, but 
it seems to me there were other chips that were 64-bit at the time.

> Of course system design was limited by RAM availability and pricing,

Exactly. Memory wasn't anywhere near as cheap in the early-to-mid '90s 
as today. So to find even an 8 GB system would have been rare, and 
excessively expensive for a single individual's engineering workstation.

> but this means that there was not much differentiation between
> 32bit and 64bit systems at the bottom line.

64 bits applied to several things:
- Physical address, as you mentioned
- Virtual address (here Alpha could have way more than 4 GB)
- Register size (allowing 64-bit arithmetic operations instead of having 
to break them up into multiple 32-bit operations)