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Re:New Mac Pro by chx on Monday June 03, 2019 @08:18PM (#20090483)
We are past that now, new PCIe 4.0 SSDs just have been showcased along with the new AMD chips and they can do 5GBytes/s read and a bit above 4GB/s write (AMD is rumored to have invested in the R&D of the controller). You'd need 40 GbE to match one -- and EPYC Rome, also scheduled for this fall, will have 160 lanes allowing for dozens of them. You could very easily reach 100 GByte/s read which no network will match.
Re:New Mac Pro by justinclift on Tuesday June 04, 2019 @02:01AM (#20092315)
> You could very easily reach 100 GByte/s read which no network will match.

High end networking gear already has higher throughput:

http://www.mellanox.com/page/ethernet_cards_overview

https://www.servethehome.com/mellanox-connectx-6-brings-200g...

A SAN/NAS using the same PCIe 4.0 SSD's you mention could probably fill the pipes too.

... and it would probably need a bunch of network stack tuning. ;)

Re:New Mac Pro by ti_ranger on Tuesday June 04, 2019 @03:38AM (#20092770)
>> You could very easily reach 100 GByte/s read which no network will match.

> High end networking gear already has higher throughput:

100GB/s > 200Gbps

You would need 4x 200Gbps ports to reach 100GB/s, so 2x MCX653105A-ECAT (each 2x 16-lanes) at > $700 each, and pay for 1/10th of a ~$30 000 switch, IOW 100GB/s would cost you ~ $4400, before paying for the storage.

Sure, it could be done, but it wouldn't be cheap, and you'll have used most of the PCIe lanes.

Re:New Mac Pro by justinclift on Tuesday June 04, 2019 @03:41AM (#20092801)
Agreed. Higher end network gear is $$$. :(

EPYC servers (128 PCIe lanes) would probably be the go too, not Xeons.

This is just Imagineering though. ;)

With the specifics, wouldn't it be 4 cards needed? Each card has 2x 100Gb/s ports, so 8 ports in total.

Re:New Mac Pro by tigershark on Tuesday June 04, 2019 @03:26AM (#20092696)
The 200 gb/s network adapter that you linked are 4 times slower than 100GB/s. The parent comment wrote explicitly 100 Gbyte/s.
Re:New Mac Pro by justinclift on Tuesday June 04, 2019 @03:36AM (#20092760)
Oops. Didn't spot that, sorry. :)

That being said, after re-reading the comment they're talking about adding multiple PCIe cards to a box to achieve 100GB/s of local total throughput.

That would be achievable over a network by adding multiple PCIe 200Gb/s network cards too. :)

Re:New Mac Pro by chx on Tuesday June 04, 2019 @05:47AM (#20093439)
Nah, a motherboard with enough M.2 connectors could easily exist. Or, U.2 or OCuLink. We have already seen 1P EPYC servers with six OCULink connectors...
Re:New Mac Pro by justinclift on Tuesday June 04, 2019 @07:22AM (#20093883)
Sure. My point is just that whatever bandwidth you can do locally, you can also do over the network.

As a sibling comment mentions though... the cost difference would be substantial. :(

Re:New Mac Pro by __d on Monday June 03, 2019 @10:17PM (#20091166)
Twin ConnectX6 adaptors, gives you 800Gbps, or ~1GB/s, at an absolute theoretical max.

It's good to see that local storage has finally returned to the reasonable state of being faster than network storage. SATA / SAS was a long, slow period ...

Re:New Mac Pro by tigershark on Tuesday June 04, 2019 @03:28AM (#20092711)
If it’s 800 gbps then it’s 100GB/s, not 1...
Re:New Mac Pro by __d on Tuesday June 04, 2019 @09:10PM (#20100682)
You're right. Brainfade.

So, even with protocol overhead from all the stack layers chewing up maybe an order of magnitude, that'd still leave 10GBps.

So .. I guess it's still possible, if impractical, to outperform a good PCIe SSD with the latest network interface.

Re:New Mac Pro by justinclift on Wednesday June 05, 2019 @02:29AM (#20101976)
... ~10GB/s can be done by a single 100Gb/s adapter.

More 0's needed? :)

Re:New Mac Pro by justinclift on Monday June 03, 2019 @11:06PM (#20091410)
cough 1GB/s can by done by 10GbE.

Maybe a slight typo there? Need to add a few zeros? :)

Re:New Mac Pro by __d on Tuesday June 04, 2019 @09:11PM (#20100684)
You're right, doh. See above.
Re:New Mac Pro by shaklee3 on Tuesday June 04, 2019 @01:20AM (#20092148)
Pcie 3 was not the bottleneck for SSD. They typically are only 4 pcie lanes, when they could go up to 16 for 4x the bandwidth.
Re:New Mac Pro by Tepix on Tuesday June 04, 2019 @01:56AM (#20092293)
But the standard M.2 NVMe interface happens to only have 4 lanes. PCIe4 will double the available bandwidth for these very common SSDs.
Re:New Mac Pro by mseidl on Tuesday June 04, 2019 @12:07PM (#20096310)
The new x570 motherboards will have them soon the pci 4.0 soon