SATA and ATA
in [Storage]
|
Prev: Continued problem with the ARGOSY - HD363N - Network Storage
Next: ARGOSY - HD363N - Network Storage Manual
From: J. Clarke on 14 Apr 2005 22:15 Derek Baker wrote: > "J. Clarke" <jclarke.usenet(a)snet.net.invalid> wrote in message > news:d3mpah02j6a(a)news4.newsguy.com... >> Carlos Moreno wrote: >> >>> Rod Speed wrote: >>> >>>>>>>>>Transmiting data in parallel is much more complicated than in >>>>>>>>>serial. >>>>>>>>>That's why Sata is faster. >>>> >>>>>Yeah, the shortcut was a bit short, but ultimatly, that's the reason >>>>>why. >>>> >>>> Fraid not. >>> >>> Care to give some reasons to support your argument? >>> >>> From what I've read, what Nick was claiming is true. From >>> the fact that PCB layout gets much too complicated at high- >>> speed parallel transmission to the fact that electro-magnetic >>> interference between bits is a problem, and also to other >>> circuits, mainly when several of the (parallel) bits change >>> from the 0 to 1 or from 1 to 0 simultaneously (making the >>> radiated EM pulse much stronger)... It all seems to point >>> in the direction that Nick said. >>> >>> I'm eager to hear arguments against or in favor of the above, >>> as I myself have been curious about this issue, and recently >>> found myself reading some technical literature on it (I got >>> to it from http://www.serialata.org, IIRC) >> >> The simple argument can be summed up in one acronym. "SCSI". >> >> The transfer rate on the SCSI bus, despite allowing 15 devices and an >> order >> of magnitude longer cabling, is still 20 MB/sec higher than that of >> SATA-II. >> >> Sorry, but SATA is faster than PATA for one and only one reason. The >> people >> who write the specs decided that they wanted it that way. > > More likely they decided it was easier - read cheaper - to make SATA go > faster. Unlikely given that the necessary technology was several generations old at the time. I suspect that the decision was driven more by fashion and marketing considerations than by any technological issue. >> And I do wish that that particular bunch of idiots had given some real >> thought to the connector design before they finalized the spec and stuck >> us >> with one of the most fragile connectors ever made. >> > -- --John to email, dial "usenet" and validate (was jclarke at eye bee em dot net)
From: Nick on 15 Apr 2005 01:41 On Fri, 15 Apr 2005 15:15:42 +1000, "Rod Speed" <rod_speed(a)yahoo.com> wrote: >It isnt an 'argument', its just pointing out >that Nick's claim is just plain wrong. > >The most obvious problem with his claim is that >SCSI parallel does better than SATA speed wise. And FC does fairly good compared to SCSI, even copper FC http://custom.lab.unb.br/pub/x/docs/t10/t11/document.03/03-025v2.pdf >And while serial can certainly be faster than parallel, >particularly with optical serial, its rather silly to claim >that optical serial is less complicated than parallel. Sure. Nick
From: Rod Speed on 15 Apr 2005 02:24 Nick <no-email(a)published.nul> wrote in message news:1kku51lh76ff9riqv0c8o1j90rp54n992f(a)4ax.com... > Rod Speed <rod_speed(a)yahoo.com> wrote >> It isnt an 'argument', its just pointing out >> that Nick's claim is just plain wrong. >> The most obvious problem with his claim is that >> SCSI parallel does better than SATA speed wise. > And FC does fairly good compared to SCSI, even copper FC > http://custom.lab.unb.br/pub/x/docs/t10/t11/document.03/03-025v2.pdf Sure, but there clearly isnt anything too COMPLICATED about the fastest SCSI. Yes, serial does have real advantages in the cable and connectors. >> And while serial can certainly be faster than parallel, >> particularly with optical serial, its rather silly to claim >> that optical serial is less complicated than parallel. > Sure.
From: J. Clarke on 15 Apr 2005 07:13 Nick wrote: > On Fri, 15 Apr 2005 15:15:42 +1000, "Rod Speed" <rod_speed(a)yahoo.com> > wrote: > >>It isnt an 'argument', its just pointing out >>that Nick's claim is just plain wrong. >> >>The most obvious problem with his claim is that >>SCSI parallel does better than SATA speed wise. > > And FC does fairly good compared to SCSI, even copper FC > http://custom.lab.unb.br/pub/x/docs/t10/t11/document.03/03-025v2.pdf And when SATA starts running at fibre-channel speeds, then maybe that will have some relevance. But in point of fact it's running slower than parallel-SCSI speeds, which clearly demonstrates that it was not needed for any technological reason. >>And while serial can certainly be faster than parallel, >>particularly with optical serial, its rather silly to claim >>that optical serial is less complicated than parallel. > > Sure. > > Nick -- --John to email, dial "usenet" and validate (was jclarke at eye bee em dot net)
From: Folkert Rienstra on 14 Apr 2005 18:46
"J. Clarke" <jclarke.usenet(a)snet.net.invalid> wrote in message news:d3mpah02j6a(a)news4.newsguy.com > Carlos Moreno wrote: > > Rod Speed wrote: > > > > > > > > > > Transmiting data in parallel is much more complicated than in serial. > > > > > > > > That's why Sata is faster. > > > > > > > Yeah, the shortcut was a bit short, but ultimatly, that's the reason why. > > > > > > Fraid not. > > > > Care to give some reasons to support your argument? > > > > From what I've read, what Nick was claiming is true. Not in the words he said it. The potential for SATA 'to be' faster than PATA (in being the next faster interface), is higher. PATA is at it's end, SATA is at it's start. SATA-150 and PATA-133 are probably equally fast data wise after all overhead is corrected for. > > From the fact that PCB layout gets much too complicated at high- > > speed parallel transmission to the fact that electro-magnetic > > interference between bits is a problem, and also to other circuits, Not to speak of maintaining compatability with older modes of transfer. > > mainly when several of the (parallel) bits change from the 0 to 1 or > > from 1 to 0 simultaneously (making the radiated EM pulse much stronger)... Yeah, it may blow up the whole computer. > > It all seems to point in the direction that Nick said. > > > > I'm eager to hear arguments against or in favor of the above, > > as I myself have been curious about this issue, and recently > > found myself reading some technical literature on it > > (I got to it from http://www.serialata.org, IIRC) > > The simple argument can be summed up in one acronym. "SCSI". > > The transfer rate on the SCSI bus, despite allowing 15 devices and an order > of magnitude longer cabling, is still 20 MB/sec higher than that of SATA-II. Utterly clueless allover again. Fast-320 transfer rate is 340MB/s higher than that of SATA-II. And that type of comparison of course is completely flawed in multiple ways. SATA-II 's clockrate is 'magnitudes' higher than Fast-320's. > > Sorry, but SATA is faster than PATA for one and only one reason. No it's not. You just can't compare the two just on clockrate. > The people who write the specs decided that they wanted it that way. And sensible people they were, not to try defining another (parallel) kludge but cutting the rope completely and go for serial. > > And I do wish that that particular bunch of idiots had given some real > thought to the connector design before they finalized the spec and stuck us > with one of the most fragile connectors ever made. The connector is probably fine for what it was designed for: Backplanes. They should have gone for an alternative for drives used with cabling. |