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Re: abysmally low scp performance

On Fri, 8 Jul 2022, Edgar Fu? wrote:

A common good value is 920-940Mbit/s for TCP alone.
That's approximately what I'd expect.

ssh then depends on CPU performance.
But as long as all CPUs are significantly idle, all should be OK, no?

That's NetBSD-9 vs. NetBSD-current on 7-year old hardware.
For me, it's -8 on both sides and hardware from 2008/2012.

On the sending side, it's:
wm0 at pci2 dev 0 function 0: Intel i82574L (rev. 0x00)
wm0: interrupting at ioapic0 pin 17
wm0: PCI-Express bus
wm0: 2048 words (8 address bits) SPI EEPROM, version 1.9.0, Image Unique ID 0000ffff
wm0: ASPM L0s and L1 are disabled to workaround the errata.
wm0: Ethernet address [...]
makphy0 at wm0 phy 1: Marvell 88E1149 Gigabit PHY, rev. 1
makphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseT, 1000baseT-FDX, auto

And on the receiving side:
wm0 at pci0 dev 4 function 0: Intel i82541GI 1000BASE-T Ethernet (rev. 0x05)
wm0: interrupting at ioapic1 pin 8
wm0: 32-bit 33MHz PCI bus
wm0: 256 words (8 address bits) MicroWire EEPROM
wm0: Ethernet address [...]
igphy0 at wm0 phy 1: Intel IGP01E1000 Gigabit PHY, rev. 0
igphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseT, 1000baseT-FDX, auto

Anything suspicious about that?

That HPN patch is old, the current (patch, not NetBSD) one is better.
But for most people, disabling is much easier.
So I guess it should be disabled by default?

Ugh EOL Intel Ethernet controllers.

PCI is so old that when I was the performance guy at work it was already
EOL. And the 82574L was sold to be cheap, not to be performant. I'm
trying to remember if PCIE overhead got in the way of that one.

I think 1 lane of PCIE Gen 1 barely kept up with 1G. PCIE is very
chatty and there's way more overhead than you'd think. I'm not sure how
much traffic NetBSD puts on the PCIE bus but I'm pretty sure it's less
performant than Linux and that's where we were focused at work.

In any case, I don' t know what the PCI NIC could do but I bet you're
doing just fine with your numbers.

Hisashi T Fujinaka -
BSEE + BSChem + BAEnglish + MSCS + $2.50 = coffee

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