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Old Feb 23, 2013, 05:19 AM   #26
VirtualRain
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Originally Posted by nigelbb View Post
USB2 will only deliver 30-40MB/s. A single hard disk can only sustain a maximum of about 120MB/s while many are much less. An external disk connected via the CalDigit combo card will be faster than an internal disk in a drive sled. What's not to like?
I was hoping to use it with SSDs.
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Old Feb 23, 2013, 05:47 AM   #27
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I was hoping to use it with SSDs.
I already have an SSD on a Velocity X2 using one PCIe slot. A 2-port USB3 card & a 2-port eSATA card using the other two slots. I want to add a 3rd monitor but my GTX570 only supports two so I need to free up a PCIe slot to put in a GTX120 that will also give me a boot screen. For my situation the CalDigit card will give me at least equivalent performance to what I have now.
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Old Feb 23, 2013, 11:35 AM   #28
Tesselator
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Prefaced to say that b=bits and B=bytes - (as always).
--

Part of what the CalDit guy said is true but some of it is BS too. He's just not up on the current state of things is all. Remember the internal SATAII ports offer 300MB/s each.
SATAI ~ SATAIII
  • SATA revision 1.0 - 1.5 Gbit/s - 150 MB/s
  • SATA revision 2.0 - 3 Gbit/s - 300 MB/s
  • SATA revision 3.0 - 6 Gbit/s - 600 MB/s
But we should really be using GT/s because of the same 8/10 encoding that PCIe uses is present here as well. Thus for every 10 bits of data sent only 8 of them are data we care about as users. Multiplying the above numbers with 0.8 is not as much fun as just dividing by 10. So for actual throughput the list looks like this:
SATAI ~ SATAIII Speeds (each direction)
  • SATA revision 1.0 - 1.5 Gbit/s - 120 MB/s
  • SATA revision 2.0 - 3 Gbit/s - 240 MB/s
  • SATA revision 3.0 - 6 Gbit/s - 480 MB/s
And it's a complete misnomer to think that "Real World" performance is any different at all. There are factors downstream and data treatments both upstream and downstream that can affect these speeds both positively and negatively. And of course there are also some natural physics that come into play - like rotational media seek speeds being affected by the weight of the drive heads, signal lag, and EM energy transference rates, etc. However for transfer sizes between ~300KB and 64MB (which describe 98% or our files these days) various protocols such as PTP/STP, NCQ etc., and inline subsystem components such as cache memory, overcome most of these impositions and can even lend in surpassing the manufacturer specified maximum rates by as much as 5% to 8% (typically!) and 10% to 15% in some cases. In a similar way the actual buss specifications can be exceeded by similar amounts as well. So this is to say that the common presumptions of thinking we will always get less than spec due to something no one can define, which we all call "Real World", is just wrong! If you're getting less than spec. for typical file sizes (mentioned above) there is likely one or more addressable bottlenecks causing it.


USB 2.0 - single connection, single rotational drive.



USB 2.0 - single connection, single rotational drive.



2-Drive RAID0 Internal 3TB Segate Barracuda, System caches disabled.



The situation is also similar when we begin discussing PCIe specifications and speeds. We need to match device specs across the board in order to maximize performance tho. Let not any user selectable component be a bottleneck.
Capacity Per Lane (each direction):
  • v1.x: 250 MB/s (2.5 GT/s)
  • v2.x: 500 MB/s (5 GT/s)
  • v3.0: 985 MB/s (8 GT/s)
  • v4.0: 1969 MB/s (16 GT/s)

For other lane multiples just use multiplication to determine throughput.

16 Lane Slot (each direction):
  • v1.x: 4 GB/s (40 GT/s)
  • v2.x: 8 GB/s (80 GT/s)
  • v3.0: 15.75 GB/s (128 GT/s)
  • v4.0: 31.51 GB/s (256 GT/s)

GigaTransfers are kinda nice because you can just divide by 10 for the rate in Megabytes per second. Like so:
  • 100 GT/s = 80 Gb/s = 10 GB/s
  • 200 GT/s = 160 Gb/s = 20 GB/s
And I'm old so I'm not sure what's happening with the v3 and v4 spec that it's not actually 8/10 as v1 ~ v2.x is. Perhaps someone with more current knowledge can clue us in. I got the rates for those off of Wiki.
The Caldigit multi-port cards are just that too - crippling bottlenecks! Just by looking at the card I can tell they’re using a port-multiplication scheme (or VERY strange VLSI packaging) and I would be willing to bet they only call for a x1 buss. Port-multiplexing is bad. Bad bad PM! PM is basically how your USB hubs work. One connection, one line speed, multiple devices fighting each other for that single line’s bandwidth. Bad bad fighting devices.

Remember there are four potential bottlenecks ("door-ways" or "volume controls" or "pipe spigots" or whatever metaphor you like) that the data must pass through before it enters our central system.
  1. The media device itself.
  2. The SATA to USB adapter the media is placed in,
  3. The interface card we place in the PCIe slot,
  4. And the PCIe controller.
But fear not you rouge lot, for someone sane is on the job. Notice that this maker requests 4 lanes for a 4-port card with a design offering four individual dedicated 5Gb/s USB Ports capable of delivering 2.5GB/s in total.

So that's the card and busses sussed, now all ya need to do is select SATAII or SATAIII to USB adapter that's worthy, media devices that can keep the pipes populated, and you're in like Flint. There's a pretty good article at Tom's as usual that explains things and offers some suggestions. Check that out here:

http://www.tomshardware.com/reviews/...urbo,3215.html

Last edited by Tesselator; Feb 23, 2013 at 02:46 PM.
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Old Feb 24, 2013, 02:23 PM   #29
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I didn't realise that there was such a thing as a USB3->SATA adapter. Any recommendations as to one with good performance?
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Old Feb 25, 2013, 11:53 AM   #30
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Well, I am not going to need RAID, I have miniSAS for that, I really only need it for a highspeed CF card reader and reading portable usb3.0 HDDs, which probably can't utilize it's full capacity anyway. And I do like that you can hotswap eSATA drives, although that might just be a feature of all eSATA III ports.
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Old Feb 25, 2013, 03:16 PM   #31
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Originally Posted by bsbeamer View Post
have you looked at the CalDigit FASTA-6GU3? CalDigit support is stellar
http://www.caldigit.com/fasta-6gu3/
Since I was getting a CalDigit 4TB Raid anyway (2x2GB drives), I needed an eSata card; so I got the CalDigit you referenced. It works perfectly and now I have USB3 (two ports) and eSData-6Gb (two ports).

I have a MacPro 5,1 Hex.
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Old Feb 25, 2013, 03:55 PM   #32
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I don't like being the guy who goes "but . . . but . . . but," but I have to say I've had very bad luck with the CalDigit 2 port USB3 card. Maybe the card with the eSATA ports is differently configured and works properly, but the damn 2 port card totally sucks.

CalDigit support just now sent its form-letter email: uninstall, update OS X, repair permissions, reinstall drivers. I've done that any number of times. They asked for the console log even though I attached it to my email requesting support.

They may be nice people but they have been, for me, ineffectual. Same (useless) advice repeated over and over again. And I've been polite, although on Sunday I did say I was sorry that I'd bought their card (which is true, oh yes it's true).

I have an Orico 2 port card ( like Actionable Mango's) on hand and am waiting for the proper adapters, because it won't work at all without extra power.

If that's not so good, I'll try the Highpoint, now that they claim 10.8 support.
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Old Feb 25, 2013, 05:50 PM   #33
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Originally Posted by nigelbb View Post
I didn't realise that there was such a thing as a USB3->SATA adapter. Any recommendations as to one with good performance?
Well they come in all kinds and sizes. From a simple cable to multi-connection 4 or 6 bay RAID housing.

So it depends if you're going to RAID it, you want something sitting on your desktop as a semi-permanent external device, connecting on-the-go with your laptop, or using it to fill shelved HDDs storage units.

For me it's the later. And Tom's Hardware tested the ThermalTake brand as being worthy. As in nearly full spec USB 3.0 transfer rates. Here's the units looks and prices:

http://www.ebay.com/itm/Thermaltake-...item2327c5f290

http://www.ebay.com/itm/Thermaltake-...item53f2a3cbaf

Of course the dual cradle won't support full speed for both drives if simultaneously accessed - where said throughput would exceed the USB 3.0 spec.

I also think this device is extremely interesting: http://us.toshiba.com/accessory/PA3927U-1PRP (I think perfect for laptops!!!)

And USB 3.0 external video cards are here now too (which basically the one just above has). I watched some product demos of full speed super-cards playing the toughest games around just by connecting a 4 year old wimpy laptop to them via USB 3.0. Pretty awesome stuff!

So soon I guess we can expect to stop seeing questions in here about how to hack video cards for use in ancient MacPro machines.

Last edited by Tesselator; Feb 25, 2013 at 06:02 PM.
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Old Feb 26, 2013, 10:36 AM   #34
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I also think this device is extremely interesting: http://us.toshiba.com/accessory/PA3927U-1PRP (I think perfect for laptops!!!)

And USB 3.0 external video cards are here now too (which basically the one just above has). I watched some product demos of full speed super-cards playing the toughest games around just by connecting a 4 year old wimpy laptop to them via USB 3.0. Pretty awesome stuff!

So soon I guess we can expect to stop seeing questions in here about how to hack video cards for use in ancient MacPro machines.
While I can see the usefulness of that for a laptop, I must say that looks like a terrible bottleneck waiting to happen!
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Old Feb 26, 2013, 12:20 PM   #35
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While I can see the usefulness of that for a laptop, I must say that looks like a terrible bottleneck waiting to happen!
The Toshiba thing? Yeah, agreed! It would be OK for light use but if one was to populate all those ports and expect everything to work at full speeds --- LOL... no....

I guess the surround sound and the monitor and maybe a USB3.0 card reader would work all at the same time without too much lag. If one were also to try and connect fast HDDs to it I guess things could get pretty icky pretty fast.

etc.
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