> -----Original Message----- > From: Alain M. [mailto:ala...@pobox.com] > Sent: Thursday, February 05, 2009 12:08 PM > To: freedos-user@lists.sourceforge.net > Subject: Re: [Freedos-user] dd for DOS? > > > David C. Kerber escreveu: > > > > I don't know; I've never looked for it. It's not just > theory, however; don't you remember the days of 5ns SRAM > caches on motherboards, when the DRAM had access times of 60 or 70 ns? > > 5ns is 200MHZ, that is so slow... > > :)
Of course, that was in the days when CPU speeds were 200MHz - 300MHz. I imagine it has sped up just like DRAM has in recent years. SRAM is still used in the L1 cache on many cpu chips, but is pretty much gone from from the motherboard. > >> In the same category: parlel is faster than serial. then > why is SATA > >> faster then IDE? > > > > The issue with parallel is that the bits must be reasonably > synchronized across all the data lines, which means you can't > drive them all that fast in an inexpensive flat cable. If > you were to build each bit's data line as a full-blown > transmission line (differential drivers, controlled > capacitance, etc) you could run it many times faster than it > goes now, and get overall faster speed. However, that gets > really expensive, and would require changes to the > electronics on each end as well. > > > > So, if you're going to change the electronics anyway, it's > overall cheaper to build high-quality tranceivers and serial > cables that only have a few wires in it, and drive it much > more than 8x faster than a parallel data cable, giving you > overall faster data transmission. > > I was just joking in making a point.... but you gave me the > ONLY inteligent explanation that I have EVER seen !!! I guess my EE degree has some use after all!!! :-D > Thanks, > Alain You're welcome, and take care! Dave > -------------------------------------------------------------- > ---------------- > Create and Deploy Rich Internet Apps outside the browser with > Adobe(R)AIR(TM) software. With Adobe AIR, Ajax developers can > use existing skills and code to build responsive, highly > engaging applications that combine the power of local > resources and data with the reach of the web. Download the > Adobe AIR SDK and Ajax docs to start building applications > today-http://p.sf.net/sfu/adobe-com > _______________________________________________ > Freedos-user mailing list > Freedos-user@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/freedos-user > ------------------------------------------------------------------------------ Create and Deploy Rich Internet Apps outside the browser with Adobe(R)AIR(TM) software. With Adobe AIR, Ajax developers can use existing skills and code to build responsive, highly engaging applications that combine the power of local resources and data with the reach of the web. Download the Adobe AIR SDK and Ajax docs to start building applications today-http://p.sf.net/sfu/adobe-com _______________________________________________ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
