Tim Rowledge wrote:
> 
> On Tue 09 Feb, Markus Kohler wrote:
> 
> > RDRAM ( Rambus memory) supported by new chips from Intel and AMD will
> > support more than 1GByte/second this year.
> Ah, I wish; unfortunately, so far as I understand it, RDRAM does a great job of
> improving _streaming_ performance but not much for random access.

What I know is that the first RDRAM had a high latency. The newer
generation (Direct
RDRAM) should improve latency. It think there needs to be some support
from the processor
to get the  full speed of Direct RDRAM. 

>  This is good
> for cache line filling, but not so helpful as one might hope for Smalltalk.

Do you have any idea why ?
Could it be improved ?

> Smalltalk's locality of reference is _terrible_. Is Mario W. still reading this
> list? If so, he might be able to correct me, but I remember him asserting that
> simulations shewed that you could really do with a 128MB cache. Yes, MB, not
> KB. Still a little expensive....
> 

RDRAM will also be more expensive than SDRAM. This is because it's a bit
more
difficult to produce and there's a license fee to pay to RAMBUS (the
company that ownes the patents). 
So don't expect it to appear in low end systems first. 
AMD's K7 might be the cheapest way to get it. It also supports a 200 Mhz
bus ( I think only for 
L3 cache). 


Markus

-- 
Markus Kohler  mailto:markus_kohler at hp.com