*OT* WD Demos 12Gbps SAS SSD *OT*

Just thought I'd pass on this little tidbit from one of my VAR Newsletters:

http://www.crn.com/news/storage/232...hgst-to-demo-12-gbps-sas-ssds.htm?cid=nl_stor

12Gbps - that's a full 1080P HD movie transferred in a second (4.8 Gigabytes per second). Yummy.

mnem
Can I get that with Chocolate RAM sauce?

 

Can't wait for you senior wizards of tb's hacking this into our machines!

 

Thats cute!

 

maybe we'll get that 12Gpbs (~1.5GBytes/s) speed in a SATA4 interface in a couple of years...
you can buy today a PCIe SSD drive, with that read speed, and ~1TB capacity, for a bit over 3k.
Newegg.com - OCZ RevoDrive 3 X2 series RVD3X2-FHPX4-960G PCI-E 960GB PCI-Express 2.0 x4 MLC Internal Solid State Drive (SSD)

 

Pssst... they're suggesting 4.8GBytes/sec... sustained. BIG difference.

mnem
TSSSSST... Smokin'!

 

re-reading the article:

this new Hitachi SSD has 2 x 12Gbps ports, so using link aggregation it has a 24Gbps connection to the controller.

One port has 12Gbits/8 = 1.5GBytes/s (excluding signaling overhead)
because SAS, as well as SATA use 8b/10b encoding, the maximum theoretical speed is even lower, 1.5*8/10 = 1.2 GBytes per second.

It has 2 ports, so that's 2.4 GB/s.

IF (as it seems from the article) we count total port speed read and write (FULL-duplex) than we could have 2 x 2.4 = 4.8 GB/s.

But when you write a movie to the SSD you're only transferring data one-way,
so only 2.4GB/s. that's considering the SSD can sustain that speed.
i.e. there are WD Caviar Green HDD's with SATA3 (6Gbps) interface, that would never reach even 200MB/s read speed, let alone 600MB/s as the interface supports.

But, as current SATA SSDs exceed 500MB/s, I wouldn't be surprised to see one soon doing 2.4GB/s sustained speed.
That OCZ Revo Card is close, double the number of parallel channels and it's even faster.

so it seems, we were both wrong...

 

Well, you should know that SATA is pretty well capped at 6 Gb/s. In order to use 12Gb SAS, you have to add (somehow) a SAS host adapter, which does not exist today in any form for a laptop (and likely never will). Getting the dual port feature to run in order to use it to stripe data across the two ports would be a huge further challenge. In addition to the electronics problem the OS driver would have to support the striping. I don't think that MS does this at all. Dunno about LINUX.

It is nice to dream, though.

Dave

 

i'm sure there won't be any SAS (an enterprise server standard) controller on a laptop(consumer), it doesn't make any sense.
However, SATA versions seem to follow the SAS versions, at least they did untill now (regarding speed).

What has already appeared (Macs from 2011 and a few other laptops) is a Thunderbolt port (Intel Light Peak) which is a 10Gbps interface, some sort of external universal PCI Express combined with DisplayPort on a miniDP connector.

Hope the some of the new models from Panasonic would include that.

 

Why not a bootable drive for the PC/Express slot? They have adapters that will take a PCI card.

 

Though there is not a completed PCIe interface for drives yet, I agree that is a likely future drive interface.

Dave