Discussion in 'OT Technology' started by perfectgetaway, Sep 7, 2006.
can yuo put a scsi into a laptop? an sites with info would be great
external only, and that'll be through a pcmcia card, and that'll efectivly slow the data transfer down enough to make it not worth the effort
I'm wondering where it would fit
Get a laptop-sized Serial ATA hard drive with NCQ, and a laptop that supports NCQ. NCQ is the only thing SCSI has that IDE doesn't have nowadays, at least regarding anything you'd ever use in a laptop.
The new SCSI standard, called Serial Attached SCSI, is closely related to Serial ATA such that some of the better SAS controllers can use SATA drives as well.
The SCSI version of NCQ is called TCQ.
thanks for the info guys
Do any laptops have expansion slots?
They have RAM slots, Cardbus slots, a 2.5" hard drive bay, and sometimes they have an adapter to allow a second hard drive to fit in the place of the DVD drive. Most laptops have a single mini-PCI slot, but it's occupied by the wireless card 99% of the time. I suppose you could try to find a mini-PCI SCSI card and jigger it up to connect to the internal drive bay, but that would involve major surgery -- assuming mini-PCI SCSI cards and 2.5" SCSI drives even exist. I've never heard of them.
Heh...shows what I know. Here's a mini-PCI Ultra160 card.
I also got a few hits for 2.5" scsi drives, but they were either pitifully small or the links were broken or the drive wasn't the standard thickness. So I say it's still easier to just get a laptop with an SATA controller and use an SATA drive with NCQ.
Yeah no point - SCSI's entire advantage is based on its ability to run multiple drives faster - single drives don't have any advantage.
My SATA suggestion reminds me of a question I've had for a while, that I haven't really gotten a clean, consistent answer on.
Does NCQ require any hardware or software support, or could I plug an NCQ-enabled drive into any computer and have it work like it's supposed to?
From what I have read, the SATA drive controller also needs to support NCQ for it to work.
I've had people adamantly declare that NCQ absolutely does need hardware support, and other people adamantly declare that it doesn't. Has anybody actually used an SATA hard drive with NCQ, such that they know firsthand what's required to make it work?
The drive controller needs to know the requested data could come back in a different order than was requested. You would get all sorts of errors if the drive just started reordering the requests and sending the data back to the controller but the controller was expecting the data to come back in the original order. Things just wouldn't work right.
Hmm. So, between the reassurance and the Seagate whitepaper, it seems that indeed Jolly was wrong when he repeatedly told me that NCQ operated entirely within the hard drive, and that no other special hardware was needed.
That settles that. Now the question becomes, are there any laptops that support SATA with NCQ?
Is that even possible???
Well...I did feel a slight tremor as I was typing that.
Well, NCQ does sort of operate entirely within the hard drive. The hard drive makes its own determination as to what is the best order for the reads and writes based on the current location of the drive head in relation to the platter. So techincally, different manufacturers could see better/worse performance with NCQ compared to other manufacturers if there are flaws in their algorithms to determine what is the best order for the operations. The controller plays no part in deciding the order of operations. The only thing the controller really needs to to know the drive can reorder the reads/writes and be able to handle data being returned in a different order than requested. If the controller can't handle that, the drive can't use NCQ.
Didn't sun have SCSI laptops for a while?
Which, in short, means that NCQ-capable hard drives need NCQ-aware controllers.