Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!zaphod.mps.ohio-state.edu!pacific.mps.ohio-state.edu!linac!convex!swarren From: swarren@convex.com (Steve Warren) Newsgroups: comp.sys.amiga.advocacy Subject: Re: Blitter vs. 040 (was: Computer Architecture question Message-ID: <1991May10.180908.29565@convex.com> Date: 10 May 91 18:09:08 GMT References: <1991May9.070349.15151@neon.Stanford.EDU> <3496.tnews@templar.actrix.gen.nz> Sender: usenet@convex.com (news access account) Organization: CONVEX Computer Corporation, Richardson, Tx., USA Lines: 24 Nntp-Posting-Host: neptune.convex.com In article melling@cs.psu.edu (Michael D Mellinger) writes: [...] >Hmmm. So, how well can the NeXT perform animation? The 68040 is >definitely faster than 2 68030s. In an 040 A3000 does the blitter >become a bottleneck. Meaning could things be done faster if the CPU >was used instead? The blitter must offer some functionality that a >"normal" CPU doesn't. In the A3000, the 68030 can update display memory faster than the blitter can. This does not mean that there is no advantage to using the blitter (and the blitter does not loose by *that* much). The fact is, if the blitter is used to manage the display and the '030 is able to stay out of display memory, then the '030 will be able to "multiprocess" in parallel with the blitter. So if you have calculations that need to be performed then, it is advantageous to use the blitter to offload graphic manipulations from the CPU. What is the avg. available bandwidth from the NeXT '040 directly into display memory? The performance of the CPU chip is not as important as the availability of the display memory bus to the CPU. -- _. --Steve ._||__ Warren v\ *| V