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It will be Nikon Sony and Canon who set the fate of USB3 vs TB on Apple products
Does anyone seriously think they will go with TB?
 
USB 3.0 should be faster than a *single* spinning hard drive, but it can be a bottleneck if you have many devices or if some of them are RAID-0 or SSD.

You also have an issue of increased latency with cache reads - with single drives showing up with 64 MiB caches, reads that hit in the cache will be slowed by USB 3.0, even with a single drive.

TBolt should be fast enough for single drive cache reads, but if you have a number of drives it could become noticeable. People who say that "you need an SSD to really use TBolt" aren't thinking about running multiple drives at once.
My 5400RPM 2TB WDC Elements hard drive tops out at 26MB/s, according to the Activity Monitor.
bildschirmfoto20110626uf.png

This equals 208MBit/s, times two = 416MBit/s. Let's add some overhead and make it 480MBit/s (as it was a little faster when it was empty). So two of those cheap, slow drives saturate USB2.0. A Mac Mini has four of those ports, which equals in a total RAID of 8 of those drives.

AFAIK, a Caviar Black would go more in the direction of 100-110MBit/s. One of them saturates FW800 by itself, without even touching the topic of caches. As most Macs only have one FW800 port, that's the end of the story.

Enter USB3. Let's have a quick quote from the "canonical source of all knowledge", Wikipedia:
Universal Serial Bus 3.0 Specification said:
A new feature is the "SuperSpeed" bus, which provides a fourth transfer mode at 5.0 Gbit/s. The raw throughput is 4 Gbit/s, and the specification considers it reasonable to achieve 3.2 Gbit/s (0.4 GB/s or 400 MB/s), or more, after protocol overhead.
So, what's to say about USB3 goes more or less for FW3200 as well (as FW is more efficient than USB3), may it or may it not been superseeded by Thunderbolt.
A four-drive RAID0 or little more than half a SATA-III SSD saturates one of those ports. I don't think that the cache on those disks is much faster in terms of transfer speed, but in terms of latency.

Again, AFAIK, if you don't hook up a display to your Thunderbolt port, it features 2x10GBit/s full-duplex. For me, this equals a 25-disk RAID0 of those 7200RPM disks, or 6.66 SATA-III SSDs. For that kind of bandwidth, you need 4 USB3 ports.

From that point of view, I conclude this:
USB2: 5400RPM hard drives and USB sticks.
USB3: 7200RPM hard drives and 2 drive RAIDs like the MyBook II Studio, as well as SandForce-1 SSDs.
ThuBo: SandForce-2 SSDs and RAIDs > 2 drives.

Unless the ThuBo chip costs like $1, it just isn't economically feasible to put it in the other categories I mentioned, because you could go ahead and buy something that is faster by default without RAID0-ing it. Then USB3 and ThuBo make sense.

74718088.gif
 
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My 5400RPM 2TB WDC Elements hard drive tops out at 26MB/s, according to the Activity Monitor.
Image

Seriously flawed test - the disk is bottlenecked by USB, so you conclude USB is good enough?

On my Dell Studio XPS mini-tower system (24 GiB, Core i7 940, x58), I have
Code:
                                                     Cache
Disk ###  Status  Size     Type         Maker   RPM   MiB  Rd MB/sec
--------  ------  -------  ------------ ------- ---- ----- -----------
Disk 0    Online   120 GB  Vertex 2     OCZ     SSD         230
Disk 1    Online   750 GB  ST3750630AS  Seagate 7200  16    101
Disk 2    Online   750 GB  ST3750640AS  Seagate 7200  16     80  (older)
Disk 3    Online  2000 GB  ST32000542AS Seagate 5900  32    120
Disk 4    Online  1500 GB  ST31500541AS Seagate 5900  32     92
Disk 5    Online  1500 GB  ST31500541AS Seagate 5900  32     91
Disk 6    Online  2000 GB  ST32000542AS Seagate 5900  32    110
Disk 7    Online  2000 GB  ST32000542AS Seagate 5900  32    115
Disk 8    Online  2000 GB  ST32000542AS Seagate 5900  32    121
Disk 9    Online  1500 GB  ST31500541AS Seagate 5900  32    110
Disk 10   Online  1500 GB  ST31500541AS Seagate 5900  32    106
Disk 11   Online  2000 GB  ST32000542AS Seagate 5900  32    110
Disk 12   Online  2000 GB  ST32000542AS Seagate 5900  32    110

Read speed for spiral outer track raw I/O, 512 KiB buffers, two threads (double-buffered). The 5900 RPM disks are Seagate "Green LP" drives.​


From that point of view, I conclude this:
USB2: 5400RPM hard drives and USB sticks.
USB3: 7200RPM hard drives and 2 drive RAIDs like the MyBook II Studio, as well as SandForce-1 SSDs.
TBolt: SandForce-2 SSDs and RAIDs > 2 drives.

Perhaps you should rethink this. Virtually any current 2.5" or 3.5" spinning hard drive will overwhelm USB 2.0.

Anyone using more than one drive at once would want even higher bandwidth. The real advantage of TBolt isn't that it can drive RAID-0 SSD arrays, but that you can have several external hard drives and run a number of them at full speed without slowing down.
 
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You are wrong. Apple is guidde solely by profits. Since USB 3.0 support is not included in current Intel chip sets Apple is bulking at paying $3 extra for additional controller chip to add it to Mac computers.

And hurting their own reputation. This new 16-core Mac Pro is going to look pretty stupid without USB3. Spend $6000+ on a new computer and no USB3 for a lack of a $3 part in bulk? WTF.... :rolleyes:
 
Seriously flawed test - the disk is bottlenecked by USB, so you conclude USB is good enough?

On my Dell Studio XPS mini-tower system (24 GiB, Core i7 940, x58), I have
Code:
                                                     Cache
Disk ###  Status  Size     Type         Maker   RPM   MiB  Rd MB/sec
--------  ------  -------  ------------ ------- ---- ----- -----------
Disk 0    Online   120 GB  Vertex 2     OCZ     SSD         230
Disk 1    Online   750 GB  ST3750630AS  Seagate 7200  16    101
Disk 2    Online   750 GB  ST3750640AS  Seagate 7200  16     80  (older)
Disk 3    Online  2000 GB  ST32000542AS Seagate 5900  32    120
Disk 4    Online  1500 GB  ST31500541AS Seagate 5900  32     92
Disk 5    Online  1500 GB  ST31500541AS Seagate 5900  32     91
Disk 6    Online  2000 GB  ST32000542AS Seagate 5900  32    110
Disk 7    Online  2000 GB  ST32000542AS Seagate 5900  32    115
Disk 8    Online  2000 GB  ST32000542AS Seagate 5900  32    121
Disk 9    Online  1500 GB  ST31500541AS Seagate 5900  32    110
Disk 10   Online  1500 GB  ST31500541AS Seagate 5900  32    106
Disk 11   Online  2000 GB  ST32000542AS Seagate 5900  32    110
Disk 12   Online  2000 GB  ST32000542AS Seagate 5900  32    110

Read speed for spiral outer track raw I/O, 512 KiB buffers, two threads (double-buffered). The 5900 RPM disks are Seagate "Green LP" drives.​




Perhaps you should rethink this. Virtually any current 2.5" or 3.5" spinning hard drive will overwhelm USB 2.0.

Anyone using more than one drive at once would want even higher bandwidth. The real advantage of TBolt isn't that it can drive RAID-0 SSD arrays, but that you can have several external hard drives and run a number of them at full speed without slowing down.
Yeah, you comparing "Read speed for spiral outer track raw I/O, 512 KiB buffers, two threads (double-buffered)." to my real world data here. As it's the only drive connected to USB, I don't see any bottlenecking in the 37MB/s area.
bildschirmfoto20110627u.png

Well, let's call that a read speed of 40MB/s, 320MBit/s. I keep my opinion that USB2.0 is for one of these drives completely sufficient in real life.
If you see numbers above 100MB/s on 7200RPM drives, then you need USB3 - whose 3.2GBit/s will surely power at least 3, if not 4, of those per port.

IMHO, your benchmarks are flawed, as it looks to me like you're not even reading the outer track, but the cache. Your drives don't come with 2000GB of most outer tracks or cache, do they? Mine come with spinning platters, with outer and inner tracks and some two-digit MB of cache (except Momentus XT).
If we go by caches here, my USB2.0 5400RPM drive is capable of delivering over 800MB/s:
bildschirmfoto20110627u.png

Ramdisk cache (I assume), hard drive cache or read from whichever track wouldn't even matter.
But this image has nothing to do with real life applications, is not informative on this particular topic and actually BS.
All I see in real life are the 40MB/s I stated above, and for those, USB2.0 is sufficient - and conclude the same as before.

74718088.gif
 
So if you care, go buy a PCIx USB 3.0 card for $30?

People (the smart ones) will do just that. The real question though is about Apple. How smart are they not providing what's became the best available standard bus port out there? There is still a chance that new Mac Pro will have USB 3.0 ports.
 
Yeah, you comparing "Read speed for spiral outer track raw I/O, 512 KiB buffers, two threads (double-buffered)." to my real world data here. As it's the only drive connected to USB, I don't see any bottlenecking in the 37MB/s area.

Do you seriously believe that current SATA drives top out at under 40 MByte/sec?
 
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My WD Green 500 GB runs 60-100 MB/s. :confused:

The peak speed requires a lot of conditions to meet but it is faster than 40 MB/s,

And the "green" one, while "server grade" (sorry could not pass on this one) obviously is not a very fast drive.
 
And the "green" one, while "server grade" (sorry could not pass on this one) obviously is not a very fast drive.
No, I bought it 3 years ago on a Frys gift card. I still have about 100 GB left on it. It is perfectly fine for storage but I would not use it as a boot drive. (Personal experience.)
 
Latency is higher and you have to waste a slot. And for $6000, IMO it definitely should be on the motherboard in 2011 (USB3 has been out for some time now).

Unless I'm missing something my understanding is even USB 3.0 would interface to the south bridge, whereas PCIx is on the north bridge. I would think a pcix usb 3.0 card would run pretty much as fast as a southbridge-connected usb 3.0 chip.
 
Unless I'm missing something my understanding is even USB 3.0 would interface to the south bridge, whereas PCIx is on the north bridge. I would think a pcix usb 3.0 card would run pretty much as fast as a southbridge-connected usb 3.0 chip.
That depends on the board and PCH used. I have seen boards with PCIe x1 slots directly to the processor or IOH. Otherwise they are off of the PCH/FCH/SB.

So many sockets. So many acronyms. At I managed to confirm that X79 is a PCH. Sheesh!
 
That depends on the board and PCH used. I have seen boards with PCIe x1 slots directly to the processor or IOH. Otherwise they are off of the PCH/FCH/SB.

So many sockets. So many acronyms. At I managed to confirm that X79 is a PCH. Sheesh!

Is X79 finally PCIe 3.0 or 2.0? Intel has finally driven me to confusion.
 
Is X79 finally PCIe 3.0 or 2.0? Intel has finally driven me to confusion.
Supposedly the current LGA 1155 based Sandy Bridge processors have PCIe 3.0 support. Intel just decided not to enable it. (There was even a Z68 board with PCIe 3.0 at Computex. Do not ask me how that works.)

LGA 1356/2011 (SB-EN/EP) is going to be the PCIe 3.0 platform until Ivy Bridge ships bring it to the "mainsteam". 24-40 lanes of that goodness for workstations this year. I do know that X79 is a PCH connected over DMI 2.0 + PCIe to the processor.

I am expecting the usual 16 lanes (x8/x8) for PCIe 3.0 under Ivy Bridge mainstream and a possible bump to DMI's bandwidth. Panther Point (Intel 7 Series, except for X79) is bringing native USB 3.0 to the PCH. You might need an external controller for more ports but expect that to be limited to premium boards. LightPeak is still going to require an additional controller.
 
LightPeak is still going to require an additional controller.

I thought that "Light Peak" has been cancelled, and that there's a "Copper Peak" that has some of the features of "Light Peak".

I could be wrong though, since no "Light Peak" or "Copper Peak" peripherals are being sold yet....

But I have seen that you need an additional large chip (usually with a heat sink) on the mobo for "Copper Peak".

;)
 
I would buy a Pegasus tb drive if one was around. Announced in Feb, wrote Promise in April; they said mid May; June comes; They say mid June; June goes and four months latter there is just one piddly little LaCie tb drive to choose from. How is one supposed to adopt thunderbolt if it doesn't exist on anything? Why the incredibly slow uptake LaCie, and why the no show Promise? Apple must be non too pleased. Wait wait wait...I wish they had only adopted USB3 as well at least we'd be able to hook something up by now.
 
Usb3

I see a lot of kvetching about the lack of USB3 on the Mac side and the main reason we don't see it is that Intel hasn't really released their own chipset yet - the present USB3 chipsets are non Intel and since Intel are the ones dragging their feet producing a chipset (won't be out until next year) that's why you aren't seeing it. Macs use Intel motherboards so put two and two together.

Maybe there will be a Thunderbolt to USB dongle adapter someday.

And for me Thunderbolt would be important. Why? Because I do lots of audio using lots of disc I/O and bottlenecks are a total buzzkill.
 
I see a lot of kvetching about the lack of USB3 on the Mac side and the main reason we don't see it is that Intel hasn't really released their own chipset yet - the present USB3 chipsets are non Intel and since Intel are the ones dragging their feet producing a chipset (won't be out until next year) that's why you aren't seeing it. Macs use Intel motherboards so put two and two together.

Maybe there will be a Thunderbolt to USB dongle adapter someday.

And for me Thunderbolt would be important. Why? Because I do lots of audio using lots of disc I/O and bottlenecks are a total buzzkill.

Apple has been this way for a long time now when it comes to USB. They resisted adding USB for a long time and when they finally did put USB into Macs, PC's were using 2.0 and Apple only offered 1.1. I'm guessing that maybe USB is something that Steve Jobs isn't personally interested in? If other computer manufacturers can use Intel processors and give their users USB 3.0 then I don't understand why Apple couldn't do the same.
 
Apple has been this way for a long time now when it comes to USB. They resisted adding USB for a long time and when they finally did put USB into Macs, PC's were using 2.0 and Apple only offered 1.1. I'm guessing that maybe USB is something that Steve Jobs isn't personally interested in? If other computer manufacturers can use Intel processors and give their users USB 3.0 then I don't understand why Apple couldn't do the same.

What? Apple was the first to offer USB only on the iMacs. At the time that they did, USB 2.0 wasn't out, and while there were a few manufacturers that had started putting one or at best two USB ports on their computers, those ports were rarely used, since even keyboards and mice continued to be PS/2 on the PC. Apple pushed the USB standard to popularity, but they don't feel that adding USB 3.0 is worth adding an extra chip to their board at this time. I don't see the problem, really. Anyone who needs the speed is still going to go FireWire, for a variety of reasons, so the only advantage of USB 3.0 is getting to use certain peripherals for which a FireWire version isn't made at a faster speed than the dog-slow USB 2.0.

jW
 
What? Apple was the first to offer USB only on the iMacs. At the time that they did, USB 2.0 wasn't out, and while there were a few manufacturers that had started putting one or at best two USB ports on their computers, those ports were rarely used, since even keyboards and mice continued to be PS/2 on the PC. Apple pushed the USB standard to popularity, but they don't feel that adding USB 3.0 is worth adding an extra chip to their board at this time. I don't see the problem, really. Anyone who needs the speed is still going to go FireWire, for a variety of reasons, so the only advantage of USB 3.0 is getting to use certain peripherals for which a FireWire version isn't made at a faster speed than the dog-slow USB 2.0.

jW

Bravo Sierra! I had one of those early iMacs. Mine was a blue and white 500MHz G3. It had USB 1.1 when my friends had USB 2.0 on their computers. That G3 was my first Mac and my first computer, period. At that time I used to go to forums like this and read the threads in an effort to learn more about my new computer. And even back then people were complaining that Apple was only giving us crappy USB 1.1 while windows users were using USB 2.0. I will freely admit that my memory isn't as good as it used to be and I might be wrong about this, but I really don't think so. I can remember reading that Apple grudgingly gave Mac users USB, but it was FireWire that they were pushing as their standard. All I'm saying is this, Apple charges a very real premium for their machines and that's fine, but if they are gonna give us USB on our Macs then at least give us the most up to date hardware possible. We pay enough that we DO deserve that. And please don't give me any of that excuse that the only USB peripherals are X, Y, and Z and you only need blah, blah, blah. When I buy a brand new Apple computer I plan on using it for years. I still have and can still use that blue and white G3. I want the most up to date hardware because I can and will keep and use my computer for a long time. When I bought that original G3, I bought it because I was returning to college after being out of school for a long time. One of the friends I met was a woman whose husband was still making a living using a really old Mac with what she described as the first version of Photoshop. That was in ~ 2000 or 2001.
 
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