Onomatopoeic
Learning Storage Performance
LSI Logic is at it again, beating everyone else to the table with new technologies!
http://www.lsilogic.com/products/islands/sas_island.html
Serial Attached SCSI
- Thread starter Onomatopoeic
- Start date
LSI Logic is at it again, beating everyone else to the table with new technologies!
http://www.lsilogic.com/products/islands/sas_island.html
blakerwry
Storage? I am Storage!
2.4 GB's a second out fo a compaq? no way!
lol.. thos do look like compaq's though....
LSI seems to be doing well... good prices, new technology... maybe we'll get lucky and they'll put adaptec out of business.. or atleast make their prices competitive.
lol.. thos do look like compaq's though....
LSI seems to be doing well... good prices, new technology... maybe we'll get lucky and they'll put adaptec out of business.. or atleast make their prices competitive.
GIANT
Learning Storage Performance
blakerwry said:
Well, now that I'm looking at those CPU illustrations, yes they are Compaq boxen -- older DeskPro models.
Which Compaq are you talking about? If it's a generic "vomit box" with a Compaq badge stuck on it in Taiwan or China on an assembly line with *identical* E-Machines and whatnot coming off as well, I'd doubt you'd get much more than 100 MB/s. However, if you are talking about ANY Compaq, then they have a few server boxes with multiple PCI-X buses that might just do it or at least come close.
Besides, the 3 GB/s is really a theoretical (total) bandwith that will include all overhead along with data. The datalink rate will be 3 GB/s, even if it was connected to a Presario or E-Machines clone. Data throughput (read or write) would be a whole lot less for sure.
LSI Logic is undoubtedly putting the squeeze on high-priced Adaptec, and beating them to market as well. On a side note, Adaptec has Serial Attached SCSI hardware in the works as well.
Fushigi
Storage Is My Life
Folks, the illustration shows Gb/S, not GB/S. Kindly divide your enthusiasm by 8; 9 if you use parity. :lol:
- Fushigi
- Fushigi
GIANT
Learning Storage Performance
Fushigi said:
Actually, I meant to mention THAT, too, but fell into the bB trap due to sleep depravation here at work. :zzz: :erm:
cas
Learning Storage Performance
The physical layer of SAS is exactly the same as SATA II (which will be available around the same time), such that you will be able to plug SATA drives in to an SAS HBA. The advantages of SAS are additional features, like dual ported drives, rather than raw performance.
GIANT
Learning Storage Performance
cas said:
Yes, SATA2 <---> SA-SCSI compatibility is a fact that has been uttered occasionally around here during the past few months; with channnel rate starting off at 3Mbits per second, rising to 6 Mbits per second after a few years, etc.
Along with advent of cost-effective iSCSI and the fact that SA-SCSI and iSCSI products will all be compatible across vendor lines with a faster 3Mbit channel rate -- including the clever co-opting of SATA into the fight -- Fibre-Channel is beginning to get hit from every angle.
time
Storage? I am Storage!
I assume you meant G as in Giant rather than M as in Miant?
Pradeep
Storage? I am Storage!
cas said:
Does dual ported drives mean that daisy chaining will still be possible?
GIANT
Learning Storage Performance
Pradeep said:
In a nutshell, "dual-ported" refers to the physical communications interface. The SA-SCSI interface (Fibre-Channel included) can perform reads and writes simultaneously over the 2-each twisted pairs.
Notice how I said "interface," not mentioning what is actually going on with the drive heads. The steps of just getting past processing commands in the interface -- much less actually receiving and processing the blocks of data -- is a significant part of the battle in gaining device efficiency. The heads of a hard drive waste a fair amount of time doing nothing when they shouldn't be.
An interface capable of full-duplex communication is at the heart of a high performance interface. Serial ATA drives will not be able to perform full-duplex communication, just half-duplex. The channel bandwidth is yet another parameter, and there seems to be plenty of bandwidth at 3Gb per second for the years 2003, 2004, and part of 2005. By the end of 2005, we will all be complaining about the sluggish 3 Gb/s channel rate and beating the table with out fists screaming "I WANT MY 6 GEE BEE!"
Cliptin
Wannabe Storage Freak
GIANT said:
Money for nothin' and the chics for free.
GIANT
Learning Storage Performance
time said:
Indeed, I definitely Geant, I mean Meant, Gb/s up there earlier, which is starting to mean Gigglebytes Per Second at this point for Ge, I mean Me.
Also, I forgot to mention in my last post that a single SA-SCSI / SATA cable contains 2-each shielded twisted pairs.
I think I'm starting to lose it and don't quite realise it. These non-stop extended work days since ...er ...way the heck back towards the end of December are ongoing, unfortunately.
Cliptin
Wannabe Storage Freak
cas said:
Will SATA have full-duplex over only one of the two ports?
Dïscfärm
Learning Storage Performance
Pradeep
Storage? I am Storage!
Thanks for the info G 
Well, don't thank me, as it seems the double-entendre strikes again! :evil:Pradeep said:Thanks for the info G
After looking at yet more SA-SCSI (SAS) propaganda, apparently what some SAS marketeers are calling "Dual Ported" indeed means a SAS device such as a disc or tape drive with an onboard repeater circuit that will allow daisy-chaining of SAS devices on one Serial SCSI bus. Dual Ported is a word I wouldn't have used for this feature.
Also, this is a feature that will allegedly be phased in at some point in time AFTER the introduction of SA-SCSI in mid/late-2003.
Pradeep
Storage? I am Storage!
I was reading that SA-SCSI increases the cable length from the 1m of S-ATA to 6m. But how will this affect external devices that currently on LVD can be up to 12/25M depending on the number of devices attached? Or will SA-SCSI be pretty much an internal connection?