Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!van-bc! From: lphillips@lpami.wimsey.bc.ca (Larry Phillips) Newsgroups: comp.sys.amiga.hardware Subject: Re: GVP Trade-in Message-ID: <1898@lpami.wimsey.bc.ca> Date: 25 Aug 90 22:59:08 GMT Lines: 42 Return-Path: To: van-bc!rnews In <02048.002057@thiger.UUCP>, skraw@thiger.UUCP (Stephan von Krawczynski) writes: >2. why is DMA so important for you? it is generally slower than the >processor-method (lets call it this way). you win nothing because you >have a whole lot of DMA going on already inside the system and processor's >running into heavy troubles sometimes, e.g. harddisk-performance is >very low while using overscan-graphics (just to mention an example). You are completely wrong in this. Not only is DMA faster, but it frees up the processor for other things. Do not confuse one particular implementation of a DMA controller, which did have a significant problem under heavy DMA conditions, for the entire spectrum of controllers. >well, how about "transfer rates up to 4MB/SEC synchronous" (gvp). in fact >i have never understood this one. what do they mean? 4MBytes/sec? No. they mean 4 MBytes per second, and that is indeed realistic. Of course you have to realize that they are not taking about sustained troughput, but about the actual data transfer rate as seen on the SCSI bus, from a Controller to Host Adapter. >i have never seen a controller/hd-combination reaching this. Several do it all the time. Note the difference between SCSI bus transfer rates and disk to destination throughput. >4MBits/sec = 512kBytes/sec. seems to be more like the truth, but is an >absolutely ridiculous value (ALF3 makes over 200kBytes/sec more in a >standard amiga - NO processor-card installed) >i think it's a reputable company, what do you think? Reputable probably. Slow, definitely. -larry -- It is not possible to both understand and appreciate Intel CPUs. -D.Wolfskill +-----------------------------------------------------------------------+ | // Larry Phillips | | \X/ lphillips@lpami.wimsey.bc.ca -or- uunet!van-bc!lpami!lphillips | | COMPUSERVE: 76703,4322 -or- 76703.4322@compuserve.com | +-----------------------------------------------------------------------+