Path: utzoo!utgpu!water!watmath!clyde!att!rutgers!rochester!cornell!batcomputer!gould!steinmetz!uunet!portal!cup.portal.com! From: thad@cup.portal.com (Thad Thad Floryan) Newsgroups: comp.sys.amiga Subject: Re: CRETIN MANOR MAIL Message-ID: <10062@cup.portal.com> Date: 16 Oct 88 01:25:20 GMT References: <7699@gryphon.CTS.COM> <3220@hubcap.UUCP> Organization: The Portal System (TM) Lines: 79 Gary, J.Dow's insults don't bother me; you should see what transpired on BBS-JC when I posted the following in response to a posting by the VP Marketing of a well-known Amiga 3rd party hardware manufacturer (names masked with "***" (but the correct length) to protect the guilty): ==================== `` Re: the claims made by ******* for the ***** interface (re: "500K per second"), that sounds more like 500 K *BITS* (not bytes) per second. Why? Per the stats accompanying the DiskPerf program, a Sun 3/50 moves data from the disk around 230 Kbytes/second, and writes to the disk around 182 Kbytes/sec. These figures are independently corroborated by various tests published in UNIX REVIEW magazine. Also from UNIX REVIEW (Vol.6, No.9, Sept. 1988) page 96, we see (for reads): Altos 386 Compaq 386/20 NCR Tower IBM PS2/80 IBM PC RT Series 2000 MS/DOS 32/400 SCO Xenix 386 AIX UNIX 16MHz 80386 20 MHz 80386 16MHz 68020 ESDI ESDI ST-506 ESDI 122 Kbytes/s 200Kbytes/s 52 Kbytes/s 54 Kbytes/s 269 Kbytes/s From UNIX REVIEW (Vol. 6, No.7, July 1988, page 96), we get disk reads for the Sun 4/260 in the range 500 KBytes/sec to 700 KBytes/second (depending on the block size). This is with an SMD interface. From the DEC catalogs, the performance of the RA81 on a large VAX is around 230 KBytes/second. Do you still wonder why I doubt *****'s veracity? The point I wanted to make is that many better designed disk subsystems on generally acknowledged "good" computers are NOT capable of performance in the realm that ******* claimed. We're speaking here of SMD, ESDI and Micro-channel systems, with DMA, disk-cacheing, etc. As an example, the Altos has a separate CPU solely to manage the disk. The ONLY way I could believe the (undocumented (e.g. test environment NOT stated, what disk, etc.)) alleged 500KBytes/second would be if the system has multi-tasking shut down, the interface was having its registers read in a busy wait loop, *AND* the disk was capable of providing sustained data transfer onto the bus at 500Kbytes/second. This is NOT the way any sane person is going to use the Amiga for doing anything "real." The claim of 500Kbytes/second implies that a 10MByte FILE can be read into the Amiga in 20 seconds. Or let's make it easier: a 2MByte can be read into RAM in 4 seconds. As I said before, if it CAN do that (read a 2MByte file into RAM in 4 seconds), then this should be touted. ******* stated ***** was NOT going to be demo'ing at AmiEXPO, so who can verify the claim? That Sun 4/260 is the RISC-based SPARC processor at 16MHz rated at 10 MIPS (by Sun) with a highly optimized SMD disk channel, and IT is reading at "only" 500 Kbytes/second. If the Amiga (with *****'s interface) is outperforming that, then why hasn't this been publicized other than here in an "in passing" comment by *******? '' ==================== I mean public replies such as "GOD DAMN YOUR ASS THAD" were posted in direct response to the above. Nothing like objective "Point : CounterPoint" ! :-) Thad Floryan [ thad@cup.portal.com (OR) ..!sun!portal!cup.portal.com!thad ]