4 ms·

PCIe 4.0 is double the bandwidth of PCIe 3.0, which is about 1 GB/s per lane, or 16 GB/s for PCIe 3.0 x16. PCIe 4.0 x4 would be ~8 GB/s, and x16 would be 32 GB/

PCIe 4.0 is double the bandwidth of PCIe 3.0, which is about 1 GB/s per lane, or 16 GB/s for PCIe 3.0 x16. PCIe 4.0 x4 would be ~8 GB/s, and x16 would be 32 GB/s. Unfortunately, the spec won't be finalized for another couple years. http://en.wikipedia.org/wiki/PCI_Express#PCI_Express_4.0 http://en.wikipedia.org/wiki/PCI_Express#PCI_Express_4.0

comex 13y ago
> PCIe 4.0 x4 would be ~8 GB/s That's what I said, 64 Gbps. :)
- WiseWeasel 13y ago
  Oh wow, yeah... didn't realize it was 20 Gbits/s for TB2 and not GB. It's not even close to as fast as currently shipping PCIe 3.0 x16, at 2.5 GB/s versus PCIe's 16. I guess external video cards are not really much of an option. Even using up all six TB2 ports won't get you as much bandwidth as a single PCIe 3.0 x16 slot.
  - Sammi 13y ago
    Notice that Thunderbolt 1/2 are full duplex. With Thunderbolt 2 you get an independent 20 Gbit/s channel in each direction. http://www.anandtech.com/show/7049/intel-thunderbolt-2-everything-you-need-to-know http://www.anandtech.com/show/7049/intel-thunderbolt-2-every...
- seanp2k2 13y ago
  I feel like Apple is betting the farm on Thunderbolt being the future, and I don't see that future materializing. How many Thunderbolt peripherals have y'all even seen in real life that weren't the Apple external monitor or a mini displayport display adapter? I feel like this is even less prevalent than Firewire was back in the 1394 glory days (it was/still is an excellent bus for running audio, due in no small part to the fact that it's not USB; separate controller, doesn't crash if your USB bus gets wonky, etc.).
  - beedogs 13y ago
    They're not "betting the farm" on it: they're locked into Thunderbolt because Intel sold them an end-to-end platform, from CPU to chipset to everything in between. That "everything in between" includes Thunderbolt; it's the reason you haven't seen the latest USB on a Mac in forever. Even in spite of a dearth of options, Thunderbolt was the only way to go on a Mac because Intel said so.
    - mikeash 13y ago
      "it's the reason you haven't seen the latest USB on a Mac in forever." Do I misunderstand what you mean by this? USB3 is rolling out on Macs and available on most of them today. (I think the Mac Pro is the only one currently lacking it.)
      - beedogs 13y ago
        Right, you can get it on the very latest Macs, most of which are just rolling out now and none of which have been out for more than a year. USB 3 is old at this point; most manufacturers started shipping devices and computers with USB 3 ports in 2009. But because Intel didn't adopt USB3 until their Panther Point reference platform in 2012, Apple really didn't have much of a choice. (Intel really, really wanted people to use Thunderbolt, even though there weren't any Thunderbolt devices available.) It took four years from when the standard was finalized for Macs to finally start shipping with USB 3.
  - ithkuil 13y ago
    one of the mistakes with Firewire is that they underestimated the royalties issue, which afaik wasn't repeated with Thunderbolt (but I might be wrong)

comex 13y ago

> PCIe 4.0 x4 would be ~8 GB/s That's what I said, 64 Gbps. :)

WiseWeasel 13y ago
Oh wow, yeah... didn't realize it was 20 Gbits/s for TB2 and not GB. It's not even close to as fast as currently shipping PCIe 3.0 x16, at 2.5 GB/s versus PCIe's 16. I guess external video cards are not really much of an option. Even using up all six TB2 ports won't get you as much bandwidth as a single PCIe 3.0 x16 slot.
- Sammi 13y ago
  Notice that Thunderbolt 1/2 are full duplex. With Thunderbolt 2 you get an independent 20 Gbit/s channel in each direction. http://www.anandtech.com/show/7049/intel-thunderbolt-2-everything-you-need-to-know http://www.anandtech.com/show/7049/intel-thunderbolt-2-every...
seanp2k2 13y ago
I feel like Apple is betting the farm on Thunderbolt being the future, and I don't see that future materializing. How many Thunderbolt peripherals have y'all even seen in real life that weren't the Apple external monitor or a mini displayport display adapter? I feel like this is even less prevalent than Firewire was back in the 1394 glory days (it was/still is an excellent bus for running audio, due in no small part to the fact that it's not USB; separate controller, doesn't crash if your USB bus gets wonky, etc.).
- beedogs 13y ago
  They're not "betting the farm" on it: they're locked into Thunderbolt because Intel sold them an end-to-end platform, from CPU to chipset to everything in between. That "everything in between" includes Thunderbolt; it's the reason you haven't seen the latest USB on a Mac in forever. Even in spite of a dearth of options, Thunderbolt was the only way to go on a Mac because Intel said so.
  - mikeash 13y ago
    "it's the reason you haven't seen the latest USB on a Mac in forever." Do I misunderstand what you mean by this? USB3 is rolling out on Macs and available on most of them today. (I think the Mac Pro is the only one currently lacking it.)
    - beedogs 13y ago
      Right, you can get it on the very latest Macs, most of which are just rolling out now and none of which have been out for more than a year. USB 3 is old at this point; most manufacturers started shipping devices and computers with USB 3 ports in 2009. But because Intel didn't adopt USB3 until their Panther Point reference platform in 2012, Apple really didn't have much of a choice. (Intel really, really wanted people to use Thunderbolt, even though there weren't any Thunderbolt devices available.) It took four years from when the standard was finalized for Macs to finally start shipping with USB 3.
- ithkuil 13y ago
  one of the mistakes with Firewire is that they underestimated the royalties issue, which afaik wasn't repeated with Thunderbolt (but I might be wrong)