I got a little frightened because I tether nikon D800 over usb3 on the new MP. But the article said as long as you only have one device on the bus it's ok. The tether is smoking fast btw
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USB 3 Slower on nMP
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I got a little frightened because I tether nikon D800 over usb3 on the new MP. But the article said as long as you only have one device on the bus it's ok. The tether is smoking fast btw
Not really. First off we are talking about limiting USB 3.0 to 80% of its theoretical max speed. Most storage solitons that use USB 3.0 will never come close to this max.
Second, it is not Apples fault that Intel did not include USB 3.0 Native support in their chipset if Xeon processors. Apple could have easily just not included USB 3.0 thus would have forced everyone to TB right? At least this way you have an option to use ISB 3.0 even if not at its fullest.
Third,there are only so many PCIE lanes on a motherboard. If they gave more bandwidth to USB 3.0 then they would have to take it from somewhere else or drop a feature altogether. Which would you do?
Apple has to live with the same limitations everyone else does. What would you give up?
I would have made the tube a little bigger, and included two CPUs. That would have provided enough lanes for everything.
Using Anandtech's image that was just quoted:
You have a 500 MB/sec link to a single GbE port - which needs 100 MB/sec.
You have a another 500 MB/sec link to a second single GbE port - which needs 100 MB/sec.
You have a third 500 MB/sec link to the WiFi card - which is maybe 100 MB/sec to 200 MB/sec.
Do you see that all three NICs could have been on a single 500 MB/sec lane, freeing lanes for the USB 3.0 controllers?
AidenShaw said:
Find me an electrical switch that can do what you believe they should have done and I will commend you. At present I know of Nothing that can do what you think they should have done. Also I am not aware of any chip that can combine all three NICs into one chip either. So again Apple can only do what is physically possible. They have a rediculous R&d budget I'm sure they had already thought of trying that.
I guess Apple engineers are just stupid and clueless.
A simple PCIe switch/mux would have made for a much better design, but in this case Apple was either cheap, lazy, or didn't think it mattered.
As a proud owner (future owner? Pseudo owner? Sigh.) of a hex nMP I am really bummed by this compromise. Upgrading from a 2008 mbp i was almost as excited for usb 3 as I was for thunderbolt. Guess ill be getting a dock for sure then.
Do you know of one? One that literally can share a single PCIE 2,0 land amongst 3 different chips?
Yes, these are common on computers that have oversubscribed PCIe lanes. Typical ASUS, Gigabyte, and other motherboards use these all the time to divide a limited number of PCIe lanes amongst a variety of different chips/functions on the main board for USB, networking, etc.
PLX is a common supplier of these kinds of PCIe switches/bridges...
http://www.plxtech.com/pcie
The PLX 8604 would have been perfect for sharing a single lane amongst the three networking chips (see page 2 of the product brief).
You may not know this but I believe the the top two slots in the old Mac Pro (4,1 and 5,1) use a PCIe switch/bridge like this to share the same 4 PCIe lanes.
According to Anand, Apple even used a PLX switch to divide PCIe bandwidth amongst the three TB controllers.
It's odd they didn't bother with a switch bridge for the networking/USB I/O. As I said, they were cheap, lazy, or didn't think it mattered. I suspect the latter. The thing is, it probably won't matter for a lot of people.
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Honestly, I don't understand why 10-20% difference in USB3.0 speed is so important.
If you need speed for storage, 6 TB2 ports are there.
I think, USB3.0 provides general peripheral connection and inexpensive storage connection and its speed covers the majority of single HDD (other than RAID).
I know some SSDs, like Samsung 840, are faster than 400 MByte/Sec, but again, if speed is critical, why don't you consider TB2?
If you need speed for storage, 6 TB2 ports are there.
I think, USB3.0 provides general peripheral connection and inexpensive storage connection and its speed covers the majority of single HDD (other than RAID).
I know some SSDs, like Samsung 840, are faster than 400 MByte/Sec, but again, if speed is critical, why don't you consider TB2?
True, but I think for the OP it is more a downgrade from his older Mac where USB3 is concerned. Not something you would expect to happen really so hoping there is some setting or he's found a bug?
Edit: 60MB/s slower is significant.
I do intend to get tb2 drives, now that ive got a machine coming that has it. The point is if you didnt yet have a machine with tb2/usb3 and/or had usb 3 drives and/or for whatever reason are working with usb 3, theres a chance performance could take a hit and on such an expensive "pro" machine thats not really optimal. Its not the end of the world or even cause for me to cancel my order but after spending so much i kind of expected 4 full fledged usb 3 ports. I knew the xeon line didnt yet have usb 3 but still reading anands review was quite a rude awakening.
i already have a few usb 3 drives, having bought them knowing there were in a sense future proof. I could use them now as crappy usb 2 drives and whenever I got a new machine theyd be nice and fast. more preferable to me than buying anymore fw800 gear. thankfully i have no usb ssds but still. Even as someone familiar to Apples attitude toward compromises the slight hobbling of usb 3 on nMP is surprising and saddening.
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I understand the feeling that OP feels why new MP is slower than rMBP on USB3.0 seed. But in reality, can we notice 10 to 20% difference on storage speed in every day's use? I think, if it is 50%, some people recognize the difference. If it is twice or half, most of the people recognize the difference. But 20%? I doubt.
Apple is trying to push Thunderbolt, so *of course* they don't care if they hobble USB3 in the name of, "Well, we had to take a shortcut somewhere..."
Apple knows that most people won't notice, know or care. That's why they say, "Ignorance is bliss." I'm sure you won't notice / care if someone takes 10-20% of your money when you're not paying attention, or if Starbucks puts 10-20% less coffee in your cup before snapping the lid on it.
Apple knows that most people won't notice, know or care. That's why they say, "Ignorance is bliss." I'm sure you won't notice / care if someone takes 10-20% of your money when you're not paying attention, or if Starbucks puts 10-20% less coffee in your cup before snapping the lid on it.
Apple has always had a hate relationship with USB. Their interface of choice was FireWire of course, and they resisted USB 2 for as long as they could. Then when they got it, the implementation sucked. They've egregiously had horrific bugs in the USB stack for years. My 2009 MP had USB problems from day one. First I had to use a Bluetooth USB Dongle because the inbuilt BT was so bad. Then it continually dropped connection. Imagine using your mouse to get WORK DONE and it drops out every hour. Guess when they fixed the last of these bugs? Last year. Amazing.
The nMP has limited PCIe lanes, but I'm surprised (or not) they only allocated one to USB, and one EACH to the three network interfaces, which won't use a fraction of that. Why not put the two ethernet on a single PCIe lane and reserve two for USB? Mystery ...
Though in my use case their choice was better actually. USB will just do light duty work for me.
A tad unfair I think cos they had to make a fudge and have a discrete USB3 chip as the chip set doesn't have one built in. Perhaps they did hobble it slightly but they favoured TB2 over it and that's the way they are pushing it.
If you need extreme USB 3.0 you will have to buy a one that bridges via Thunderbolt, or wait 18 months for the Haswell Xeon chipset 7,1 as that will have USB 3.0 baked in the chipset silicon.
If you need extreme USB 3.0 you will have to buy a one that bridges via Thunderbolt, or wait 18 months for the Haswell Xeon chipset 7,1 as that will have USB 3.0 baked in the chipset silicon.
Well.. this 4x card for the cMP uses 4 PCI lanes, 5Gbs per port, 20Gbs total:
But alas, won't fit in Oscar's new hangout, even if you add wheels.. lol
But alas, won't fit in Oscar's new hangout, even if you add wheels.. lol