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From: lindsay@gandalf.cs.cmu.edu (Donald Lindsay)
Newsgroups: comp.arch
Subject: Re: Segmented machines and per process memory limits.
Message-ID: <11871@pt.cs.cmu.edu>
Date: 9 Feb 91 19:42:27 GMT
References: <9101312359.AA07832@ucbvax.Berkeley.EDU> <1360007@aspen.IAG.HP.COM>
Organization: Carnegie Mellon Robotics Institute, School of CS
Lines: 20

In article <1360007@aspen.IAG.HP.COM> 
	huck@aspen.IAG.HP.COM (Jerry Huck) writes:
	[Zalman Stern, MIPS Computer Systems,writes:]
>>Of course you would think that
>>by now hardware designers would get the message that portable OS'es do not
>>use segmentation hardware and hence putting it on the chip is a waste.
>
>What do you mean here?  

I think he means that the IBM RS6000 and the HP-PA would have been
better architectures if they had just gone with flat 32-bit address
spaces, and left off the segmentation features. I agree with him.

As far as I can tell, the resulting systems aren't noticeably better
than systems using 32 bits + good software.  If marketing phrases
such as "52 bit address" or "64 bit address" promise something extra
- power, or software simplicity - then these segmentation schemes
don't really deliver.
-- 
Don		D.C.Lindsay .. temporarily at Carnegie Mellon Robotics