Comment by belter | Hacker News Reader

Comment by belter | Hacker News Reader

Finding a bit strange the overall tone of this thread.

Running a mainframe comes with the challenges of finding specialists, relying on a single vendor, having to buy at least two in two different data centers for disaster recovery,etc...But purely from performance point of view, as in throughput, and also quality of service, the case is clear for the mainframe.

Spend some time reading the Z15 technical guide, and marvel at what is today the state of the art in computing. We are talking about sustained, full on 5.2 GHz, all the time. Massive IO bandwith, ECC memory everywhere, massive caches, native crypto co-processors.

All this, while your x86, most likely, spends most of its time waiting on memory...

"A Crash Course in Modern Hardware by Cliff Click"

https://www.youtube.com/watch?v=OFgxAFdxYAQ

IBM z15 (8561) Technical Guide

https://www.redbooks.ibm.com/abstracts/sg248851.html?Open=

https://www.redbooks.ibm.com/redbooks/pdfs/sg248851.pdf

What cloud vendors are doing is using, sometimes, custom hardware to create a mainframe at cloud scale. Its just due to the sheer incompetence of IBM management, that they were unable to leverage their mainframe technologies, and offer cloud offerings that would be competitive on a price per compute or storage unit.

But purely from performance point of view, as in throughput, and also quality of service, the case is clear for the mainframe.

No, it isn't clear. Show the benchmarks.

Please note I am talking about the mainframe as a platform.

We can start here:

"IBM z15 Performance of Cryptographic Operations"

https://www.ibm.com/downloads/cas/6K2653EJ

Can your x86 do this?

Edit: "Introducing the new IBM z15 T02"

https://www.ibm.com/training/pdfs/The_New_IBM_z15_A-technica...

==========

5.2 GHz core frequency

• On-chip compression accelerator (NXU)

• On Core L1/L2 Cache

• L2-I from 2MB to 4MB per core

• On chip L3 Cache

• L3 from 128MB to 256MB per chip

960 MB shared eDRAM L4 Cache

=========

Also a comparison of Z15 Java performance vs x86. The advantage for the mainframe comes from the additional computing capabilities like compression dedicated hardware and other components the x86 platform misses.

https://github.com/IBM/IBM-Z-zOS/blob/main/zOS-Education/Hin...

You still hadn't mentioned any relevant number.

"Linux Workload Performance on LinuxONE III / z15"

https://community.ibm.com/HigherLogic/System/DownloadDocumen...

Ok the benchmark is from June 17th, 2020 but it’s using a Xeon 6140 a Skylake chip from Q3'17. That gets crushed even by even a $125.00 E5-2670 let alone whatever your similar budget buys you.

So, I am guessing actual head to head benchmarks must be quite bad.

Yes. It has a Processor Base Frequency 2.30 GHz · Max Turbo Frequency 3.70 GHz

Your latest Intel® Xeon® E-2386G Processor, not available yet...has a base frequency of 3.50 GHz and a Max Turbo Frequency 5.10 GHz

So even with the latest...your Turbo frequency... is the base from the mainframe core...

And if you happen to be running a memory bound benchmark, with the massive caches in the mainframe, you will be crushed.

> Running a memory bound benchmark

I can easily write a memory bound benchmark that makes all CPU cache irrelevant. The only thing that actually matters is real world performance which is why actual benchmarks are so critical.

> Xeon® E-2386G Processor

That’s a chip from 2018. Anyway, you can talk about CPU clock speeds all day, but it doesn’t mean much between different CPU families.

Can't reply to response from Retric below so will do it here.

Wrong choice indeed the Xeon® E-2386G Processor its not what I was looking for. Instead of going for the latest lets review the latest offers from Intel:

https://en.wikipedia.org/wiki/List_of_Intel_processors

A few models that have a peak turbo frequency approaching the sustained frequency of Z core. Also, of course due to different architectures, internal caches, we should not be comparing purely on frequency. Although the mainframe is again wining here in frequency and cache sizes...

Also agree that what counts are real workloads with real commercial applications. I have so far posted at least three but here is another one:

"IBM MQ for z/OS on z15 Performance"

http://ibm-messaging.github.io/mqperf/MQ_for_zOS_on_z15.pdf

they appear to be bragging about 12GiB/s of aes-256-gcm per crypto accelerator. This is equivalent performance to about 2.6 cores of epyc milan, but let's be generous and say 3 cores. At retail, 3 cores of epyc milan costs $240-$360. How much does one of those crypto accelerators cost?

Can your epyc sustain this througput 24h a day ?

yeah, pretty easily, why wouldn't it? those are the post-heatsoak numbers on my desktop (running an epyc 7443p), sustainable indefinitely.

Is anyone reselling mainframe-backed VPSes then? If all this is true, they should work better and be more profitable.

Marist College does that for free. You can get a Linux VM from the LinuxONE Community Cloud that runs on a z15. You can have it for 6 months.

Not sure about that, but the idea I was proposing was use the technical capabilities that allow them to build the mainframe. I am aware of the usual challenges of distributed computing, eventual consistency, etc...

But they could have created a computing offer, using the pure core performance of the Z processors and the technologies that enable things like z/OS Sysplex and do it at cloud scale. They could then maybe be competitive on a price scale:

https://www.ibm.com/docs/en/zos-basic-skills?topic=sysplex-z...

This would be similar to AWS telling you could have your CPU core stretched across two availability zones.

Reply on news.ycombinator.com