Using 2U, 4U servers vs. smaller-form factors

In this Server Month video, alternatives to 1U servers are highlighted, as well as characteristics of 2U and 4U servers.

1U servers pack a lot of computing power, but its technology and capabilities aren’t always the best fit for a company’s particular needs.

“1U servers are the building blocks of modern data centers, but there are instances when these smaller machines aren’t right for every task,” said Colin Steele, senior site editor.

Find out when you should consider smaller-form factors, when blade servers are appropriate and which 1U server alternatives you should be wary of.

Check out the rest of our Server Month tips and videos.

Read the full transcript from this video below:  

Using 2U, 4U servers vs. smaller-form 

Colin Steele: 1U servers are the building blocks of modern data centers, but there
are instances when these smaller machines aren't right for every task.
Hi, I'm Colin Steele, Senior Site Editor.

Steve Bigelow: And I'm Steve Bigelow, Senior Technology Editor.

Colin Steele: In this video, we're going to take a look at some other server options
to serve your data center needs. Steve, can you start us off by telling us when
1U servers might not be the best option?

Steve Bigelow: I sure can, Colin. 1U servers can really go a long way in a data center,
but the technology isn't always right for every circumstance. It really is a matter of
fitting the company's particular needs. The trick with 1U servers is expandability and,
while 1U servers can pack a lot of computing power into a small package, there
really is not much expandability in a 1U form factor. You can get two processors,
a large amount of memory and a small handful of hard drives into a 1U unit, but when
you require more computing resources than that, it's really time to think about moving
up to a larger form factor. The additional physical space just gives you the room you need.
It's the right move to make if you're looking to accomplish a higher level of consolidation,
putting more virtual workloads on the same unit.

Now, an alternative to that might be a smaller form factor server, in which case you're
trying to compress a lot more computing power into a smaller area, or smaller chassis.
A small form factor server will usually offer fewer computing resources than a comparable
1U server on the whole, but the idea is you're getting a lot more computing resources into
a small area, so there's greater efficiencies to be gained there. The trick is evaluation,
you really need to understand what workloads you're running and what the goals are
for the organization.

Colin Steele: What are some of the choices you have if you decide that a 1U server
isn't right for your specific workload or task?

Steve Bigelow: Colin, you actually have a few different choices when you are looking to move
beyond 1U. If you need larger, more powerful servers, really think about a 2U or 4U server.
A 2U server is twice the height of a 1U server; it's a matter of form factor. A 4U server is four
times the height of a 1U server, so that additional physical space really lets you concentrate
more computing power in that area than you might be able to find otherwise. If you need to
pack more computing power into less space, consider a blade server, a single blade shares
a lot of similarity to a 1U server but you're getting rid of some of the memory, you are foregoing
some of the hard drives and you are concentrating the processing power into a much
smaller area, so depending on what your needs are, once again, you can make a
determination as to which form factor or server type would best suit your needs.

Colin Steele: What are some of the characteristics that we can expect to find
in these 2U and 4U servers?

Steve Bigelow: Well, Colin, when you're talking about a larger form factor you have to be
careful. More space doesn't always guarantee more computing power. You can
find that larger boxes, larger physical form factors may, in some cases, offer less
computing resources than a comparable 1U server, so you need to pay attention to
what's in the box. But when you need more computing, more disks, more expandability
for expansion cards, the larger box can really go a long way towards meeting those needs.
The move from 1U to 2U servers is really about expansion options.

For example, a 2U server may very easily stick with two multi core processors and
maybe 192 gigabytes of RAM, but you may find six PCIE expansion slots instead of
one or two that you might find in a comparable 1U server. You may also be able to
get maybe 8, 10, 12 hard drives in a larger form factor box, as well. Definitely more
resources can be available depending on how you want to outfit your server.

A 4U server can provide you with maybe as many as 8 or 9 PCIE type
expansion slots and as many as 20 or 24 hard drives in the same box,
so it can bring considerably more computing resources to whatever workload
or workloads you need to be operating. The real bottom line there is to take your
time, show some caution and really evaluate what each particular product has to offer
before you make a final product decision.

Colin Steele: That takes care of the 2U and 4U servers, what are some of the
characteristics that we can expect to find with blade servers?

Steve Bigelow: Colin, when it comes to blade servers, the name of the game is processing
ability. Now, when you have a blade server, you generally won't have any hard drives,
you may only have 24 gigabytes or so of memory, depending on the particular
model of blade that you select, but you can have two CPUs, you may even have
four CPUs for any blade in particular, so what that gives you is a lot of computing
power in a very small package, and since you can pack blades together very densely
onto a specialized chassis, it's very easy to get a lot of processing power into a small
area very quickly and very inexpensively.

Don't expect any expansion slots you may, on a blade server be able to fit one,
perhaps two, small form factor hard drives, but don't count on it. Blades,
unlike rack servers, don't standalone, so if you do opt for a blade server, you're
going to need a specially designed chassis to insert those blades into and each
individual blade will get its power and connectivity from the chassis itself. Blade
servers are usually good for web applications or other workloads that require a
lot of computing power in a very small area.

Colin Steele: We're talking about a lot of different options here, the 1U servers, 2U,
4U, blades. Does an organization have to commit to a specific kind of server?

Steve Bigelow: No, Colin. Rack servers, they don't require very much commitment. You can
mix and match 1U, 2U, 4U boxes in the same rack, pretty much to your heart's content.
The place where you really need to be careful with rack servers, is in your management
tools. If you have rack servers that are from different manufacturers, the management
tool used for one type of rack server may not properly manage other vendor's products,
so you want to make sure that whatever management tools you're using for your rack
servers that they're heterogeneous across all of the different products that you select.

Blades do take a little bit more commitment on the part of the organization because
you may not fill the blade chassis entirely, right up front, you can, but you don't necessarily
have to, and once you purchase the blade chassis, it really doesn't make any sense to use
blades from different manufacturers where you have to buy unique chassis for each and
every one of those vendors. When you're talking about blades, if those suit your needs,
it's really a matter of picking the chassis, and then systematically filling that chassis until
you've reached maximum capacity.

Colin Steele: Thanks a lot for that insight, Steve. For Steve Bigelow, I'm Colin Steele,
thanks for watching this video.


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