What are Mainframes?
Techquickie
·Techquickie
·2017-05-06
·
980 words · ~4 min read
0:00
What comes to mind when you hear the words big iron? Heavy construction,
0:05
extreme laundry, my nickname in high
0:08
school. Well, it turns out that big iron
0:12
is none of those things and usually refers to mainframe computers, massive
0:18
machines that typically live inside of large cabinets. Okay, then Lionus. So,
0:24
you're talking about a supercomput, right? Actually, no. Mainframes are
0:29
defined a little differently. In our episode on supercomputers, which you can
0:33
check out here, we discussed how they
0:37
are great at number crunching to complete extremely complex tasks like
0:43
weather forecasting, medical research, and crypt analysis. But with mainframes,
0:49
the focus is more on throughput and
0:52
reliability. So what exactly does that mean? Well,
0:56
compared to something like a supercomputer, mainframes have a lot
1:01
more inputs and outputs or IO because
1:04
they're often deployed in situations where they aren't working on one massive
1:10
complex problem, but rather they have to
1:13
process tons of smaller, simpler
1:16
transactions extremely quickly. In fact,
1:20
even though there is a popular misconception that mainframes are relics
1:25
of a bygone computing era, to process
1:29
the up to millions of card swipes and account transfers that occurred daily,
1:35
96 out of the world's top 100 banks and
1:38
23 out of the top 25 US retailers
1:42
currently run mainframes from IBM, who has been the dominant player in the
1:46
industry for a very long time. Building
1:49
one though isn't just a matter of installing a whack ton of Xeons in a
1:54
box, plugging in lots of Ethernet cables, and calling it a day. Mainframes
1:59
use special CPUs, many of which are much
2:02
larger physically than even big desktop chips like 2011 socket CPUs from Intel,
2:08
as well as additional processors called system assistance processors or SAPs
2:15
that do almost nothing but move data
2:18
around as quickly as possible, like glorified traffic controllers rather
2:24
than general purpose number crunchers. And that's not all. On a modern
2:29
mainframe like the topend IBM Z13, each
2:33
individual IO card of which there can be
2:37
160 has its own processing cores up to two
2:42
per channel on the dual channel cards.
2:46
Meaning you could have over 600 processor cores just for IO. And that's
2:53
not even counting the SAPS. Whoa. Part
2:58
of the reason that modern mainframes are designed to support this much IO is to
3:03
ensure that they stay reliable. So many of the subsystems inside a mainframe,
3:08
like a modern airliner, would have redundancies built in. This means they
3:13
can be deployed in situations where zero
3:16
downtime is acceptable, such as the aforementioned credit card companies and
3:22
retailers, as well as airline ticketing systems. In fact, a common mainframe
3:27
operating system, IBM's proprietary ZTPF
3:32
was originally developed as transaction processing software for airlines. If you
3:37
want to see it in action, pay close attention next time you board a flight,
3:41
and you might just get a glimpse of the computer screen they're using to check
3:45
you in. An old school interface with green text indicates that it's probably
3:50
a terminal connected to a mainframe. just don't look uh too closely at it. So
3:56
this high level of redundancy means that it's common for mainframes to be built
4:00
in such a way where an administrator can
4:04
slide out one of the drawers that houses components and simply start swapping
4:08
them out. Whatever that drawer was working on is automatically transferred
4:13
over to the rest of the mainframe, making it easy to make necessary
4:17
hardware changes without any downtime. which is a good thing, too, because
4:22
high-end mainframes can run tons of virtual servers at once, up to 8,000 in
4:27
the case of the Z13. Meaning that taking down the mainframe could result in a lot
4:32
of transaction errors on Black Friday.
4:35
But before you start thinking, gee, I
4:38
should get myself a mainframe cuz I want to run Overwatch on like some kind of 50
4:43
monitor setup, mainframes and their operating systems aren't just absurdly
4:49
expensive. A single mainframe can cost hundreds of thousands, if not millions
4:54
of dollars. They also aren't designed to
4:57
run games or for high-end floating point
5:00
performance, which is important for rendering graphics. But even so, main
5:06
frames are still in the background powering lots of things you do every
5:10
day, which is pretty cool. That is, unless you've sworn off air travel and
5:15
you don't want Mastercard to know about all the weird stuff you buy on Amazon.
5:19
Speaking of uh having your online activities tracked, Tunnel BearVPN lets
5:25
you anonymize yourself on the internet and browse the internet and use online
5:29
services as though you are some anonymous guy in some other country.
5:35
They have easy to use apps for iOS, Android, PC, and Mac. They also have a
5:39
Chrome extension, and it's super easy to
5:42
use. You just press a button and boom, tunnel bear's on. Your connection gets
5:47
encrypted with AES 256-bit encryption and your public IP address gets switched
5:52
so you show up as though you are in a different country. Tunnel Bear makes it
5:57
easy by bypassing all the annoying details that typically come with using a
6:01
VPN. No DNS, no uh router configuration,
6:04
no port configurations, none of that nonsense. And they've got a top rated
6:08
privacy policy and do not log user activity. So try it out for free with no
6:14
credit card required at our link in the video description. And also by using our
6:18
link, you can save 10% when you sign up for a year of unlimited. So that's
6:23
tunnelbear.com/lininus.
6:26
So thanks for watching, guys. Like, dislike, check out our other channels,
6:29
comment with video suggestions, and subscribe. Don't forget to subscribe.
6:33
That's the most important part. That's why I said it at the end.