---------- Original message ---------- Subject: Re: Flash only? WAS:Re: IS the world about to change ? Date: Montag 25 Oktober 2010N From: Dan <[email protected]> To: [email protected]
> At 1:12 PM -0400 10/25/2010, John Martz wrote: > >If you're going to discuss SSDs versus HDs then I suggest you also > >consider the relatively recent availability of hybrid SSD-HDs. > > Yea. sigh. IMO, a stupid stupid idea. … > Let's think about this. > > Instead of > interface <-> cache <-> HD, > you now have > interface <-> cache <-> big flash cache organized as a SSD <-> HD. > > Think about that. The firmware and hardware controllers, to drive > the simpler design, have been in the field for years and are > thoroughly debugged. So now they're adding a massive layer of > complexity... How many firmware updates will there be? … > Oh, but the performance of SSD! yea. heh. If this is a laptop > form factor, then you still have the power sucking HD behind things. I'm only guessing, but I read about these hybrid disk drives. Their intention is an honorable one, but I personally also think it will not be a market success – and I wouldn't buy one as I think of it as a bad idea. So, the performance of the SSD is mainly to make valued files, like startup files or files which are accessed very often, faster available through the SSD. This will speed up the startup process and, as the operating system learns (which files are often requested), the daily work. The wearing level will be not very high in such a scenario, as the files have to be updated only now and then, as the software gets updated (security fixes and such) or as the user changes his/her working behaviour. The other advantage is for mobile computers such as laptops, where the HDD is often stopped after a while if no access was required. This can be configured. If, while the drive is stopped, the user (or the Auto Save function) wants to write a file to the drive, the drive doesn't have to be started right away but is written to the SSD instead. This may also be configurable (i.e. only do this while on batteries) – AND the data will survive a complete system crash. So much about the theory. Problem is –as always with new technologies that require special treatment– it has to be supported by the operating system, and maybe also by some applications as well. Another example is the ATA TRIM command for flash memory i.e. also SSDs. Like older computers /may/ be able to also use a flash drive (even if it is only a CF-to-IDE kind of solid state memory), but without this TRIM command it will wear out ealier. I don't know if the TRIM command has to be supported by the controller chip (IDE/SATA) or if it is merly sent to the drive by the operating system's ATA driver. But what good is it anyway if the operating system supporting this new feature doesn't run on older hardware? FYI, for about the last two months I am now running my G3 B&W from such a CF memory card using an CF-to-IDE adapter. It is slower than with the HDD I used before, but the advantage is that I can leave it running all the time without fearing the hard drive will break down – the original HDD was 10+ years old. It is also much lower noise now. And, I couldn't find a new hard drive that was 40 GB or so, which I needed since I have a Rev.1 G3 B&W with the buggy IDE controller. So, running Mac OS X 10.4.11 Tiger – how about special flash drive support? No way! With now 1 GB of RAM my G3 B&W would handle cashing to the RAM very well, thus lowering the wear-out level of the CF card. Linux has such possibilities, like mounting all temporary directories to a RAM filesystem (RAM drive). But I'm not sure about the mentioned TRIM command, as it may not even be supported by the CF card itself. But even if it was, Tiger doesn't support it anyway! Cheers, Andreas aka Mac User #330250 -- You received this message because you are a member of G-Group, a group for those using G3, G4, and G5 desktop Macs - with a particular focus on Power Macs. The list FAQ is at http://lowendmac.com/lists/g-list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/g3-5-list
