
An Initial Look at the IBM POWER9 4c/16t CPU Performance on the Blackbird - MrRadar
https://www.phoronix.com/scan.php?page=article&item=blackbird-power9-4c&num=1
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neilv
The interesting thing about Raptor's Power9 boards is their emphasis on open
firmware.

But I'm disappointed that the Blackbird wasn't at a lower price point (such as
if IBM heavily subsidized it, to try to get more open source labor supporting
their architecture). It's hard to get excited about paying big bucks to
volunteer for IBM.

Personally, I'm now more interested in RISC-V boards that are even more open
than what Raptor has been doing with Power9. Something like the Raspberry Pi,
but RISC-V and more open, would be awesome.

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Crontab
> But I'm disappointed that the Blackbird wasn't at a lower price point

This sentiment is why I believe open systems, like the Raptor or RISC-V, are
doomed to never become truly popular. There are too many people more concerned
with cost and/or performance than freedom.

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neilv
There's a balance. For example, buying into a huge black box
component/architecture effectively controlled by IBM is limited freedom for
your dollar.

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robin_reala
Does having four threads per core cause more problems for speculative
execution attacks? I seem to recall that one of the fixes proposed for Spectre
was disabling hyperthreading.

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api
Those attacks can be mitigated. They're not fatal to hyperthreading. HT is a
great way to improve performance and is not going away.

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wahern
They're fatal in the sense that you can't mitigate all the side-channels. It's
intrinsic to HT/SMT that certain critical resources are shared without an
ability to mask the side-channels. What you can do is make sure that only
processes and threads with the same privilege (e.g. same UID) share a core.
But AFAIK such mitigations haven't made their way into OS schedulers.

You're almost certainly right that HT isn't going away, the performance
benefits are too great. But to fully minimize the security impact operating
systems in particular, but also some userspace applications (e.g. browsers),
will need to be aware of the problems. This is already the case more generally
for cryptographic algorithms and similar software--e.g. how memcmp can leak
passwords.

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admax88q
Unfortunately same UID is not sufficient, if my program is running some other
script or respnsing to input provided by an external user or attacker.
JavaScript is the easiest example of this.

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api
Am I missing something or were those benchmarks really as brutal as they
looked? It was beaten by a Core i3 and lower end first gen Ryzen chips.

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syn0byte
IBM advertise their "big iron" systems in Transactions Per Second. A measure
of the total system performance; IPC, Buses, caches, etc. They get shit
stomped in a traditional CPU bound benchmark. Remember Apples marketing using
"The Megahertz Myth" in their later PPC days because of how one sided
benchmarks (and clock speeds) were getting?

It's a fine arch with plenty to offer but a 1:1 comparison with an x86 desktop
is like saying that a 50 ton bulldozer just got wrecked in a race with a
Bugatti Veron.

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jacquesm
The bulldozer would even lose from a Fiat 500 or a bicycle if it came to raw
speed.

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theandrewbailey
Now that modern POWER hardware can be bought for roughly commodity prices, how
likely are optimizations to these workloads?

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metildaa
It is unlikely that significant optimization will happen outside of companies
payong for it to happen, most of the tinkerers that do this type of
optimization for fun are working on projects like Armbian, as a $15 SBC is a
more useful target than a piece of big iron.

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layoutIfNeeded
What is that black cube on top of the heatsink?

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pacetherace
Probably a piece of rubber that keeps some margin between the heatsink and the
cover of the server.

