eSATA: Five Times Faster Than USB
External Serial ATA drives will transfer data five times faster than USB 2.0, according to a demo at Intel's Developer Forum.
Source: TechWorldeSATA II is capable of 300Mbit/s while USB 2.0 crawls behind with 45Mbit/s and even the first SATA spec manages 150Mbit/s. Seagate, with the help of NetCell, demonstrated the new technology yesterday with its marketing VP Jeff Loebbaka saying it showed eSATA's "ease of use and fast data transfer rates".
The demo was at SATA I speed, 150Mbit/s, and used two Seagate eSATA 160GB, 7200-rpm, 8MB cache external hard drives with a NetCell eSATA PCI RAID card. Such eSDATA drives could be used to build an external RAID array for servers.
An eSATA backup to an external disk could complete in 10 minutes instead of 50. Some vendors have used internal SATA ports but outside the box. However that "pointing-out" of an internal SATA port is not compliant with the eSATA spec and doesn't supply the robust and easy-to-use connectors that the eSATA spec designates, or the shielded cables that preserve signal integrity.
The SATA I/O organisation "owns" the external SATA specification. It was developed because SATA drive vendors realised that, although SATA was intended as an inside-the-box specification, there was no reason why it couldn't be used to connect external SATA drives to a PC or server system. The specification was released in mid-2004 and details the shielded round cables, connectors and signals.
Shielded cables up to 2m long are used to connect drive and system via robust and easy-to-use connectors. The eSATA devices are hot-pluggable so it is perfect for connecting external drives used as backup or file transfer devices.
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Being able to slot an external eSata array into a low cost server would be kickass!
SAN & NAS setups could really, really use that kind of bandwidth
Mhhhhhh!!!!!!!!!!!!!!. Here we go again try to beat the wd 10,000 rpm sata with another abortive attempt. No thank you, I am happy with western digital
One drive, one slot. See a connection? One drive, one slot. Just more ports on a controller card.. which you can have when the connectors are as small as SATA
Oh yeah?
How about 20 channels of MPEG-2 video at 15 Mbps? (20 x 15 = 300 Mbps.) My company sells multi-channel MPEG-2 decoder circuit boards and video servers. I have customers who are doing 20 channels of 8 to 10 Mbps who are using a striped SATA RAID who would love to be able to use just 1 hard drive instead of 2, and get higher throughput as well. Plus they can still have the second SATA drive mirrored instead of striped.
Or how about 8 channels of High-Def MPEG-2 video at 35 Mbps? Or 16 at 18 Mbps? I have customers who would love to be able to do that with SATA instead of SCSI, they'd save loads of money.
Dexter...
Though I am kind of curious how exactly this can be compared to USB 2.0. When you think about it, USB 2.0 is a lot more convienient given the size of the drives. Granted the space is not nearly as large as 160gb it still seems that this tech won't be used by the "common person" like USB is.
If anyone could give me a pretty simple clarification of any uses outside of what has been given I would be appreciative
Given the choice of copying files to an external USB drive at 45 Mbps, or an external SATA drive at 150 to 300 Mbps, which would you prefer? Assuming that you are charging the customer a set fee for the service, not the time spent on it. With eSATA, you could back up data 6 times as fast, then move on to your next customer.
There's one use.
Dexter...
One of the beauties of SCSI is it's EXTERNAL capabilities as a extremely fast interface. Take a unit like the EXP400 for X series IBM servers. 14 10K 74G SCSI drives in an expansion chassis. That's connected externally to a controller in the X series. Expanding the storage capability of the server by 14 drives at no performance hit
You attach a USB2 hard drive to that server, it's not going to compete with the SCSI interface (or even the IDE!)...
eSata is an offshoot of standard SATA allowing for LOW-COST scenarios and performance that matches INTERNAL controllers. eSATA theoretically gives outstanding throughput and brings it up to almost SCSI arena for EXTERNAL devices. This means low cost SANs can built using eSATA instead of SCSI... and benefit from storage capacity of SATA
To attach more than one SATA drive you need as many ports externally as the numbers of drives you want to connect. Good thing they are freakin small and can fit a few ports on the back of the PCI plate.
USB2.0 is 480Mbps,i.e. 60MB/s. However, there is a throughput limit on a single USB device which is seldom mentioned. I forgot the exact value. It seems to be 20MB/s. Besides, there is 10% system reserve bandwidth and overhead used for "control code". I have no idea whether it is true for the thrival read/write action over the USB-to-IDE(controler) having legacy and drawing the CPU cycle to drop the overall performance. Think about the SCSI and Ultra-DMA make use of the DMA channel to faciliate the high throughput. FYI, my USB2.0 8X DVD-writer run at 11xxx Byte/s stably.
IEEE1394a(firewire) is 400Mbps, i.e. 50MB/s. Unlike the USB standard,it was designed for DV and high transfer rate demand. The bus architecture is similar to SCSI. Is seems that no throughput limitation on IEEE1394. Of course, the overhead will draw some bandwidth, which also appeared in USB. I guess the transfer rate may be up to 40MB/s.
Well, another use of eSATA would be the HDD extention of Notebook computer or high speed DVD-writer(16x or above) in future.
Note that, the bandwidth of PC Card interface:
CardBus (32 bit burst mode)
* Byte mode: 33 Mbytes/sec
* Word mode: 66 Mbytes/sec
* DWord mode: 132 Mbytes/sec
132*8~=1056Mbit/s.
Compared with SATA1.0 1500Mbit/s, the bandwidth of CardBus interface is much less than SATA1.0 . So, we should consider this limitation when do upgrade.