
IBM unveils z-series with 5.5 GHz CPU and hardware transactional memory. - TallGuyShort
http://www-03.ibm.com/press/us/en/pressrelease/38653.wss
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breckinloggins
Can anyone who works with big iron regale us with tales of modern mainframes?
These days it seems the term "mainframe" is associated with the 70s and 80s
(and COBOL!), but I'm pretty sure the contemporary mainframe market has a
bunch of cool stuff that we mere mortals hardly get to hear about.

~~~
underplank
I used to develop software for system-z(2 years ago). As someone else said, if
you are already using mainframes, get another one. If you arent, pretty much
you can ignore them. Their hardware is of higher quality, but I think their
uptime has more to do with the hermetic seal of human process that exists
around the installations. You can't get anything changed in production, ever.
And thats fine, because banks have been doing the same thing for the last 30
years.

I don't actually think performance wise they have anything on a cluster of x86
servers. But its hard to benchmark things like that accurately.

From a developer point of view, its not a great technology stack to work on.
Its old and out dated, and is pretty incompatible with other platforms. EBCDIC
is a pain, 3270 terminal is a pain. Having to allocate files manually is a
pain. Having actually about 7 different types of files is a pain.

Its really all a pain. Just dont go there.

Also, I found that guys who had been working on mainframes for a really long
time have a pretty outdated view of what the "distributed" world has to offer.
A lot of the time they dont understand what "web Scale" at the level of
google, facebook et al are operating at.

As an additional funny annecdote, the I/O that a lot of people have been
talking about is now conventional if high end disk array's AFAIK. But
internally the disks are emulated for the OS to look like the disks it was
using back in like 1975. Thats how it gets backwards compatibility, just dont
change anything.

~~~
breckinloggins
As a technologist I'm always excited about new stuff, but there's another part
of me that thinks it's really neat that some of the world's most important
software was written 30 - 50 years ago and still works just fine.

Can you imagine a time 1000 years into the future where software written today
might still be in use? How cool would that be?!

~~~
Nerdfest
Most of that software is still in use because it's very poorly written using a
combination of COBOL and assembler and people are afraid to touch it.

~~~
glhaynes
Very poorly written _and it works_ , at least.

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lotharbot
The actual system information can be found at
[http://www.redbooks.ibm.com/redbooks.nsf/RedpieceAbstracts/s...](http://www.redbooks.ibm.com/redbooks.nsf/RedpieceAbstracts/sg248049.html?Open)

As someone who never has need to touch a mainframe, it's quite strange to look
through this. It's not the 120 processor cores and 3 TB of RAM that surprise
me; it's things like the cooling system and the I/O system that are so
different from what I'm used to from working on a desktop system.

~~~
lallysingh
There's also the fact that the 120 cores are all in one cache-coherent
domain...

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jacques_chester
The funny thing is that IBM and other major DP firms have had cloud servers
for years. Decades, even. You just can't get to it with a credit card.

I've sometimes thought that a cloud provider backed onto z/VMs could be a
nifty business model. Sure, you'd be priced above even the "expensive"
providers like AWS; but then ... it's a mainframe. At the very least your
customers would get hipster cred, which tends to attract a massive markup.

~~~
EwanToo
I'm struggling to find it, but I'm certain a germany company said they would
launch a service to access Linux VMs running on zSeries.

The IBM SmartCloud Enterprise+ Service (what amazing names IBM comes up with)
does incorporate zSeries machines.

<http://www-935.ibm.com/services/us/en/managed-cloud-hosting/>

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carlesfe
I work with supercomputers.

Mainframes are very, very extended nowadays. Researchers use them, the
government uses them, some big business use them.

From my point of view, there are four "mainframe" concepts, and one of them is
not a monolithic mainframe _per se_ :

1\. Supercomputers: thousands of CPUs, each with access to a few gigabytes of
RAM, which can run massively parallel jobs

2\. Shared memory machines: 64-256 CPUs, each of them can access to 0.5-2TB of
memory

3\. GPUs: Hundreds of CPUs, each with access to 1-4 GPUs and a few gigabytes
of RAM, to run highly parallel vector jobs

4\. Clusters: Commodity hardware (either racked or workstations) connected by
a network which uses a queue system

The first three belong to the modern implementation of the mainframe, the last
one is a "supercomputing"-like facility, built with regular hardware.

This brings us to OP's article, and to my main point. There are many research
centres, business and government which use them, but there is a trend towards
using regular Intel processors instead of mainframe-like vector processors.

Why? Because they're easier to program for. Us at the Barcelona Supercomputing
Center have worked with ppc, ppc64, cell, ia64, i686 and x86_64 architectures,
and here's what happened.

Some of these architectures don't have debugging/profiling tools available.

I joke with my colleagues about how it has been 10 years from the first CPU
with hyperthreading and we still don't have fully automated tools to take
advantage of parallelism on legacy code. We know it's difficult to do, but
that has to be taken into account when planning to buy a new machine. Old code
might run slower on the new machine because of the highly parallelism but
lower raw speed.

Others (cell) are just so difficult to optimize that we needed 2 postdocs
working 2 years only to make a matrix multiplication take about 80% of the
full computing power. I'll only say that our next machine was going to be a
Cell supercomputer, but that idea was dropped after a scientific panel advised
against it.

Some months ago I took a course on GPU programming, and for those of you who
have never programmed on vector processors, it is like the Hello World in
brainfuck. My CS degree+masters wasn't just enough. It is overwhelming. The
guy teaching the course was a PhD with 3 year experience programming GPUs, and
he admitted that most of the times, if you compare the time it takes for you
to program on a GPU with the time you save running the software, it is just
not worth it. Hey, sometimes it is, and you save a lot of time. But not for
most cases. So we're back to regular Intel processors again.

What I'm trying to say is that nowadays we buy machines for different purposes
(large number of cores, large amount of memory, large throughput for vector
multiplication, etc) but _most of them are x86_64_. GPUs are an exception
because we buy software which has already been adapted to vector operations,
but somebody had to spend many days adapting the code.

We work with Intel and IBM and we have access to the most recent CPUs and
tools. IBM makes great hardware but they don't have anybody writing a
development framework for that hardware, so you never reach even 70% of its
peak throughput.

TL;DR: Yes, many companies use mainframes, but most of them try to put x86_64
processors in there, because they are easier to parallelise and there are many
tested programming tools available.

~~~
joshu
Nice rant, but not really relevant.

Unfortunately, none of these are mainframes. Mainframes are a fairly different
architecture and usually run OS/390 or z/OS these days. They really aren't
about performance computing and are more oriented towards databases and IO.

~~~
carlesfe
We also work with banks and process huge amount of data, but we don't use
those kind of mainframes.

I'm not saying nobody uses them, but rather that there is a trend to use a
NoSQL database on a regular Linux system rather than z/OS.

It's easier to find developers, more widespread support, and hopefully they
will be more compatible in the future.

Edit: chuckMcM's comment [1] provides more insight on this. I must admit I've
never worked with traditional mainframes myself, but I know of many research
groups who are trying to develop new high-troughput data channels for
commodity hardware (i.e. fibre-channel disks).

The current trend is going towards Intel+Nvidia+Linux. Anything else might be
a good investment for some, but generally a bad idea for most.

<http://news.ycombinator.com/item?id=4447122>

~~~
no-truth
Most of banks use linux boxes for downstream systems (reporting and so on) but
a mainframe is the centrepiece of it all, executing end of day batch jobs
(this can be anything from the feeds to the clearing house, or end of day
reconciliation) and processing trades.

You will be surprised, but it is due to the fact that banks were some of the
first people to start using computing decades ago, and some of the programs I
have seen in use at banks were older than me. Moving everything to a Intel
based platform removes that backwards compatability, but z/OS is made with
this in mind.

~~~
gadders
> Most of banks use linux boxes for downstream systems (reporting and so on)

I don't know - for regular client-server computing, I've seen a mix at the 6
banks I've worked at - some Linux, some Windows Server, some Solaris. Most
banks have a mix of all three, but have one that they "major" in.

Also, mainframes tend to be more of a Retail banking thing, for the core
banking platform.Some Investment Banks use mainframes for back office stuff,
but not many (in my experience).

Where I am working now, I have seen plaques in recognition for using a
particular mainframe program from VISA for 20+ years. Also, the recently-
retired core-banking platform from an acquired retail bank ran on mainframes,
but was written in assembler.

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carlic578
Putting these in place this weekend :)

~~~
breckinloggins
Just watched the intro video for the water-cooled EC12. I know nothing about
mainframes other than what I've learned reading this thread and scanning IBM's
website, but man that thing looks wicked.

I really like the "RAIM" stuff that's apparently new. It seems like a similar
idea not only to RAID, but also to this "lockstep execution" thing I just read
about. I suppose the idea is that you can configure all or certain memory
slots to be slaves such that all reads and writes are identical, or does this
RAIM stuff also have RAIM with parity for reconstruction plus storage size
increase?

Also, is the ability to install this thing on a normal (non-raised floor)
pretty new, or has that been an optional feature of larger mainframes for a
while?

Finally, the guy in the video mentioned some Java stuff. Do these things
typically see lots of Java use or are they mostly programmed closer to the
metal?

~~~
TallGuyShort
They used to be commonly programmed very close to the metal. The assembly
languages for the System 360 and 370 machines (40 - 50 years ago) were well
suited to processing records of data. These days, I believe using these as
hypervisors to hundreds of Linux VMs is more common. IBM has their own Java
implementation, but I don't know what it's adoption is like in the mainframe
industry.

~~~
Nerdfest
hey actually sell special processors that run Java for 'Free'. Most people
don't know that IBM charges you for 'MIPS'. They actually charge you for using
your computer. They have some other specialized processors as well ... all are
very expensive.

~~~
spitfire
I remember looking it up a while ago, for a processor to "run" Linux cost $28K
at the time. Not at all sure how many VM's you cuould support there.

~~~
noselasd
The previous generation could run up to 50000 VMs, I'd wager the new system
announced here could handle a lot more.

~~~
Nerdfest
They will only 'run' that number if they're not actually doing anything.

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wtracy
Can anyone comment on the implications of hardware transactional memory here?

~~~
ithkuil
I only found this [http://www.eetimes.com/electronics-news/4218914/IBM-
plants-t...](http://www.eetimes.com/electronics-news/4218914/IBM-plants-
transactional-memory-in-CPU)

any other info?

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islon
"curl <http://www-03.ibm.com/press/us/en/pressrelease/38653.wss> | grep -io
enterprise | wc -l" >44 This new CPU is very "enterprisey".

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zmonkeyz
Great hardware but we just upgraded to the z196. Maybe in a couple of years :)

