Esata (for Laptop) Go W/ It Or Usb2-ide?

[luumak]

Yet another 'technological flavor of the month' has washed ashore - eSATA.

Would you go for it assuming your laptop has built in port or just go for the usb2 gig?

i could see possibility of a need to hook it up to another machine.

the speeds look comparable to usb2, not so impressed. maybe lik efirewire its a "through-put thing", ah yes...throughput :-)

[dave_boo]

Yet another 'technological flavor of the month' has washed ashore - eSATA.

Would you go for it assuming your laptop has built in port or just go for the usb2 gig?

i could see possibility of a need to hook it up to another machine.

the speeds look comparable to usb2, not so impressed. maybe lik efirewire its a "through-put thing", ah yes...throughput :-)

eSATA has actually been around for awhile now. It's much better than USB, simply because you don't feed anything else through the bus other than the external drive, whereas with USB you'd have mice, keyboards, etc. Also, similar to a USB hub, you can hook up a port multiplier to eSATA for multiple drives on one connection.

Another issue is that a USB device has to convert the SATA (or IDE) drive signal into a usb signal and eSATA doesn't. Straight shot through. USB 2.0 has a maximum speed of 480 Mb/s versus SATA 1.5-3.0 Gb/s. So theoretical bandwidth is slower by ~3-6x. CPU usage is higher in USB. etc.

[cali]

It's much better than USB, simply because you don't feed anything else through the bus other than the external drive, whereas with USB you'd have mice, keyboards, etc.

That is not true anymore. Each USB connector on motherboards these days are on completely independent channels. Plug in 2 disk drives and they each get 480mbps.

eSATA has disadvantages. It can't power the device. You need an AC power adapter for that and then you have 110 vs 220V issues and the associated clutter. But a new eSATA spec is coming which allows bus power, but you can't benefit from that at all with todays systems. eSATA is also not as widespread. If you want something that works everywhere you go, you want USB.

Edited February 7, 2008 by cali

[dave_boo]

It's much better than USB, simply because you don't feed anything else through the bus other than the external drive, whereas with USB you'd have mice, keyboards, etc.

That is not true anymore. Each USB connector on motherboards these days are on completely independent channels. Plug in 2 disk drives and they each get 480mbps.

eSATA has disadvantages. It can't power the device. You need an AC power adapter for that and then you have 110 vs 220V issues and the associated clutter. But a new eSATA spec is coming which allows bus power, but you can't benefit from that at all with todays systems. eSATA is also not as widespread. If you want something that works everywhere you go, you want USB.

Newer computers do have multiple USB controllers. But how many people actually take the time to spread their connectors out on them? Also, every USB controller I've seen has been plumbed through the PCI bus versus the usual PCI-E of the SATA.

USB does power the device, an option that does put it over on eSATA for attaching 1.8-2.5" disks. However, it can not provide enough for a 3.5" device, and that's really what you'd want to put on eSATA. Plugging in a normal 2.5" drive into eSATA is like using a water cannon to get rid of the geckos on your ceiling.

Ubiquitiness of USB is a major point in its favour, but the hypothetical question posed by the OP was "Would you go for it assuming your laptop has built in port or just go for the usb2 gig?" Followed up by a statement that the speeds look to be the same. If it was my money(and I have), I would get an eSATA enclosure. Nobody else has to use my personal drives!!!

[cali]

Newer computers do have multiple USB controllers. But how many people actually take the time to spread their connectors out on them?

What are you talking about? You plug your devices into whichever connectors you want on the motherboard. You can't go wrong because you get a dedicated, independent hi-speed USB channel on every one of them.

Also, every USB controller I've seen has been plumbed through the PCI bus versus the usual PCI-E of the SATA.

Usual? Systems I have seen implement USB in the same chip as SATA and they are both on Southbridge.

Plugging in a normal 2.5" drive into eSATA is like using a water cannon to get rid of the geckos on your ceiling.

Not so fast, 2.5" hard drives come in 7200RPM speeds, half a terabyte capacities, SSD, and RAID.

Ubiquitiness of USB is a major point in its favour, but the hypothetical question posed by the OP was "Would you go for it assuming your laptop has built in port or just go for the usb2 gig?" Followed up by a statement that the speeds look to be the same. If it was my money(and I have), I would get an eSATA enclosure. Nobody else has to use my personal drives!!!

Agree as long as he doesn't mind the extra cable mess, the power adapter works with the voltages in the countries he will use it in, and he doesn't need to carry the drive to an internet cafe or something like that.

Edited February 8, 2008 by cali

[dave_boo]

Newer computers do have multiple USB controllers. But how many people actually take the time to spread their connectors out on them?

What are you talking about? You plug your devices into whichever connectors you want on the motherboard. You can't go wrong because you get a dedicated, independent hi-speed USB channel on every one of them.

If that were true, what is the need for USB root hubs? Check your lspci output (or Device Manager on Windows).

Also, every USB controller I've seen has been plumbed through the PCI bus versus the usual PCI-E of the SATA.

Usual? Systems I have seen implement USB in the same chip as SATA and they are both on Southbridge.

I guess I mis-spoke on this one, because definitely if you're using an Intel chipset that doesn't have 'real' controllers on it you are correct(confirmed on my laptop). I am so used to using workstations where everything has its own chip that I forget consumer grade motherboards aren't as complex (nor as expensive )

Plugging in a normal 2.5" drive into eSATA is like using a water cannon to get rid of the geckos on your ceiling.

Not so fast, 2.5" hard drives come in 7200RPM speeds, half a terabyte capacities, SSD, and RAID.

Yes they do(although I haven't seen any 1/2 TB models), and Tomshardware just did a review of them. And an average speed of ~50 MB/s is not going to overwhelm a USB 2.0 port. An SSD would, as would RAID, but those are two different beasts from a typical laptop hdd that someone would put in a 2.5" enclosure that would be powered by the USB bus.

Ubiquitiness of USB is a major point in its favour, but the hypothetical question posed by the OP was "Would you go for it assuming your laptop has built in port or just go for the usb2 gig?" Followed up by a statement that the speeds look to be the same. If it was my money(and I have), I would get an eSATA enclosure. Nobody else has to use my personal drives!!!

Agree as long as he doesn't mind the extra cable mess, the power adapter works with the voltages in the countries he will use it in, and he doesn't need to carry the drive to an internet cafe or something like that.

I have absolutely no retort for that. Believe me, I tried to come up with something and you are correct. If sheer portability over speed and capacity is required, than by all means he should get a 2.5" enclosure.

[cali]

If that were true, what is the need for USB root hubs?

A hub is a required element in the USB topology providing communication between its ports and the USB controller. The key is each root hub nowadays has exactly 1 port. Go into device manager and view by connection. You should notice every single USB device gets its own dedicated USB controller & hub! This is because once upon a time there were sharing issues between devices that effected performance as you mentioned, but the hardware guys have fixed this years ago already.

[luumak]

thanks to you all, very informative. much i had read on the web already but arguments quite compelling. i totally forgot that eSATA needs independant power source. thats a deal breaker. with laoptops still 3 kilos plus all the clutter. last thing i want/need is an ac adapter to lug about (and to burn out and replace).

excellent - thanks!!

[RKASA]

When I found the need for more storage I picked up a spare HD for the Laptop and put that in a caddy.  It needs no power other then the usb and the drive can be put in the laptop if I need to.  So its a spare part as well.

[Veazer]

Keep in mind that S.M.A.R.T. will work over eSATA connection but not USB/Firewire.

I've also been told that the HD cache is not utilized when connected to USB/FW enclosures, but I have not been able to find any solid evidence to backup that claim. I have doubts since most pre-built enclosure & drive combos state the drive cache size.

[nikster]

Has anybody actually tested their own USB 2.0 speed? Asking because I am consistently getting only 12MB/s or less - sometimes 10, sometimes 8, on the USB. And that's the ideal case, when transferring large files. Happens on both Mac and Windows, and on all three of my USB 2.0 enclosures. 2 mobile and 1 3.5" 7200 HD.

FireWire has the same nominal speed, but gives me 30MB/s consistently with large files. So that's a lot better. The 2.5" HD can do 50MB/s or so max., but in real life 30 is probably as good as it gets.

[dave_boo]

Has anybody actually tested their own USB 2.0 speed? Asking because I am consistently getting only 12MB/s or less - sometimes 10, sometimes 8, on the USB. And that's the ideal case, when transferring large files. Happens on both Mac and Windows, and on all three of my USB 2.0 enclosures. 2 mobile and 1 3.5" 7200 HD.

FireWire has the same nominal speed, but gives me 30MB/s consistently with large files. So that's a lot better. The 2.5" HD can do 50MB/s or so max., but in real life 30 is probably as good as it gets.

It would be interesting to know what type of file copying is going on when you get this speed. I.E., is it internal drive to external, or external to external? Or on all types of transfers?

While I've been stripped of the thought that USB shares a single controller (thanks to Cali ), I haven't heard anything about it still not using CPU cycles, almost exponentially as more devices try and access the bus. Perhaps this is the issue?

Also, dragging and dropping folders in Windows is not the quickest way to speedily send files. I also find Windows 'guesstimations' about speed and time remaining. The Mac on the other, not having used an Apple since ~][e days is a mystery.

Perhaps it's something as simple as bad USB cables. One thing you can try and do is download SiSoftware Sandra. It has a pretty extensive benchmarking suite that should let you determine what speed your external drives are actually capable of performing at (much easier on Linux cause you'd simply call "hdparm -T /dev/sd*). When I get back to my room, I'll give you the results of an external drive that I have....after I find the USB cable since I currently have it on Firewire.

I've also been told that the HD cache is not utilized when connected to USB/FW enclosures, but I have not been able to find any solid evidence to backup that claim. I have doubts since most pre-built enclosure & drive combos state the drive cache size.

I don't think that the buffer would be affected by being in an external enclosure. The controller built into the disk should be dropping the bits and bytes there for the OS, rather than the OS grabbing bits from the heads and dropping them there. Of course I could be wrong again!

[autonomous_unit]

I wish more people would benchmark their own system before claiming that USB speed is anything but laughable... I have also rarely seen better than 12-18 MB/s. It is meaningless to talk about the "theoretical" 480 Mb/s when actual usage gets nowhere close. Copy several full DVD images of data and time it. This should be an optimal case with large files.

On most systems I've seen, USB disk access is dog slow compared to an IDE or SATA connection. From what I've read, the problem is partly due to the USB storage protocol and partly due to the current software driver implementations. In either case, it hasn't improved any in the past few years so I wouldn't expect it to suddenly get better now...

So an answer really depends on how you intend to use it. USB is great for infrequent light usage, but if you were hoping to do lots of significant access (such as mirroring whole drives or moving many large media files while you sit tapping your fingers impatiently), an eSATA drive would be much better. A modern eSATA controller port will also let you access multiple hard drives in a single enclosure (if the enclosure implements port-multiplier functions), so it's not really a dead-end single drive solution either.

Years ago (before eSATA was popular) I gave up on having an external drive enclosure to use with my laptop. I found it was cheaper to build a whole PC with multiple disks and implement a Linux file server than to just put together a standalone RAID enclosure. I think this is still true today, until eSATA RAID enclosures get cheaper. Over gigabit ethernet, I can get far faster data transfers to the file server than I've ever seen over USB---up to 90 MB/s for direct access and 30-40 MB/s for disk-to-disk copies (since my laptop drive is the limiting factor). And for light usage, I can just go over the wireless LAN... I only drag out the ethernet cable when I am preparing to do some large transfers. I find that I also start running more tasks on the server itself, because it is faster than my laptop!