[Jack-Devel] AES67 / SMPTE ST 2110-30

Philippe Bekaert philippe.bekaert at uhasselt.be
Tue Oct 3 16:47:29 CEST 2017

The correct link for linuxptp seems to be

Anyways, happy musicmaker : you may just want to try first with your current network adapter lacking hardware time stamping. 
ptpd reports clock synchronisation accuracy in the order of microseconds. 
Others report up to 100 microseconds accuracy in absense of hardware time stamping and on a loaded network.
Thats still only 5 audio samples and the latency of your audio card is probably a lot larger than that (miliseconds at least).
You’re probably not doing highly time critical work either.
No need to rush for that (web) shop right away …



On 03 Oct 2017, at 16:18, Chris Caudle <chris at chriscaudle.org> wrote:

> On Tue, October 3, 2017 2:19 am, happy musicmaker wrote:
>> Bugger, according to this, the I210T1 requires a PCI 2.1 slot. Mine is
>> just a 2.0.
> PCIe 2.1 was basically an addendum to add additional features, all
> compliant PCIe devices are required to be backwards compatible with older
> slots. The PCIe version listed on the specification is the highest version
> that it can support with full features, not a strict list.
> Note also that there seems to be a mistake in the specification, PCIe 2
> generation should be 5GT/s not 2.5GT/s.  Possibly the device supports the
> register set and software features of PCIe 2.1 but only runs at gen 1.0
> speed of 2.5GT/s, but that  would be unusual.
> I would check the list at linuxptp.sourceforge.com for recommended
> adapters.  The linuxptp project takes advantage of the latest linux kernel
> features and does not limit itself to interfaces available in other OS
> like ptpd.   I don't know if that provides any performance advantage or
> not, linuxptp project claims that using linux specific kernel API is
> better than using generic posix API.
> This is the list of drivers which support hardware time stamping in the
> MAC layer, but you have to look at the details for the card you want to
> buy. For example, the tg3 driver supports hardware timestamping on
> Broadcom Tigon based cards, but I have a broadcom NIC which does not
> support hardware timestamping, only software.
> Note that if you have a Windows installation and want to use the ALC
> Windows virtual sound card you will need an adapater with an 82574L
> controller.
> I apologize for the poor formatting, I do not  want to use HTML email for
> the mailing list, see the linuxptp web page for an easier to read table
> format.
> 5.3.2 Hardware Timestamping - MAC
> Driver 	Hardware 	Version
> amd-xgbe 	AMD 10GbE Ethernet Soc 	3.17
> bfin_mac 	Analog Blackfin 	3.8
> bnx2x 	Broadcom NetXtremeII 10G 	3.18
> cpts 	Texas Instruments am335x 	3.8
> e1000e 	Intel 82574, 82583 	3.9
> fm10k 	Intel FM10000 	3.18
> fec 	Freescale i.mx6 	3.8
> gianfar 	Freescale eTSEC PowerPC 	3.0
> i40e 	Intel XL710 Family 	3.14
> igb 	Intel 82576, 82580 	3.5
> ixgbe 	Intel 82599 	3.5
> mlx4 	Mellanox 40G PCI 	3.14
> ptp_ixp46x 	Intel IXP465 	3.0
> ptp_phc 	Lapis EG20T PCH 	3.5
> sfc 	Solarflare SFC9000 	3.7
> stmmac 	STM Synopsys IP Core 	3.10
> tg3 	Broadcom Tigon3 PCI 	3.8
> tilegx 	Tilera GBE/XGBE 	3.12
> -- 
> Chris Caudle
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> Jack-Devel at lists.jackaudio.org
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