
AWS C4 Instances - kapkapkap
http://aws.amazon.com/ec2/instance-types/?sc_ichannel=em&sc_icountry=global&sc_icampaigntype=launch&sc_icampaign=em_130722160&sc_idetail=em_865952340&ref_=pe_411040_130722160_17#compute-optimized
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nissimk
In case anyone else was wondering what "ability to control P-States and
C-States" is about, I think this is a useful reference [1]. I guess with the
C4-8Xlarge you control the entire physical machine and you can enable
additional P-states to get more power out of the cpu while using more
electricity.

[1] [http://www.xenserver.org/partners/developing-products-for-
xe...](http://www.xenserver.org/partners/developing-products-for-
xenserver/19-dev-help/138-xs-dev-perf-turbo.html)

~~~
tedunangst
That's a strange feature to include on a machine I'm not paying the power or
cooling bill for. Why would I ever set it to anything other than 11?

~~~
dbarlett
From [https://aws.amazon.com/blogs/aws/now-available-
new-c4-instan...](https://aws.amazon.com/blogs/aws/now-available-
new-c4-instances/) :

    
    
      In some cases, your workload might not need all 18 of the cores (each of which
      runs two hyperthreads, for a total of 36 vCPUs on c4.8xlarge). To tune your
      application for better performance, you can manage the power consumption on a
      per-core basis. This is known as C-state management, and gives you control over
      the sleep level that a core may enter when idle. Let’s say that your code needs
      just two cores. Your operating system can set the other 16 cores to a state that
      draws little or no power, thereby creating some thermal headroom that will give
      the remaining cores an opportunity to Turbo Boost. You also have control over
      the desired performance (CPU clock frequency); this is known as P-state
      management. You should consider changing C-state settings to decrease CPU
      latency variability (cores in a sleep state consume less power, but deeper sleep
      states require longer to become active when needed) and consider changing
      P-state settings to adjust the variability in CPU frequency in order to best
      meet the needs of your application.

~~~
tedunangst
I question the real world utility/practicality of this, but thanks for the
explanation.

To elaborate: I start with (e.g.) a 2 cpu c4 instance. But my single thread
performance isn't fast enough. So I'm going to spend a king's random to
upgrade to a 36 cpu instance, just so I can disable 35 of those cpus? There
are several other options I'd probably investigate first.

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latch
Ran UnixBench

c4.2xlarge
[https://gist.github.com/karlseguin/a659ef87b3a4a5d590e9](https://gist.github.com/karlseguin/a659ef87b3a4a5d590e9)

c4.8xlarge
[https://gist.github.com/karlseguin/0f38b9ad87ebd54375da](https://gist.github.com/karlseguin/0f38b9ad87ebd54375da)

i7-4770
[https://gist.github.com/karlseguin/5a6a45ace2048545b6c3](https://gist.github.com/karlseguin/5a6a45ace2048545b6c3)

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wise_young_man
For those who prefer AWS blog posts over the product page:

[https://aws.amazon.com/blogs/aws/now-available-
new-c4-instan...](https://aws.amazon.com/blogs/aws/now-available-
new-c4-instances/)

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api
Still damn expensive compared to things like a dedicated server from here:

[http://www.kimsufi.com/en/](http://www.kimsufi.com/en/)

Amazon seems to offer more network bandwidth though, so they might have an
advantage for CPU-heavy and network-heavy loads. But from the testing I've
done Amazon comes in almost dead last for cost/performance on most metrics. I
suppose they could make sense if you make heavy use of all their services, and
maybe their cost/performance improves with scale?

~~~
meltedice
Most of the servers on that page aren't even running ECC RAM. The only one
listing ECC RAM is the E5504 which dates back to 2009 whereas C4 is running
the fastest Xeon model available today. The rest of the list is Intel Atom and
i5 and i7 desktop chips. 60% of the server types on that page are also
currently out of stock.

~~~
lsb
Where does EC2 say that they are running with ECC RAM?

~~~
meltedice
here: [http://aws.amazon.com/ec2/faqs/](http://aws.amazon.com/ec2/faqs/)

~~~
lsb
Oh awesome, thanks!

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moe
Pricing still looks pretty far out there.

Their CPU has a passmark score of 16k[1] and they ask $1300 USD/mo for it.

Hetzner will rent you one with passmark 10k[2] for $60/mo...

[1]
[http://www.cpubenchmark.net/cpu.php?cpu=Intel+Xeon+E5-2680+v...](http://www.cpubenchmark.net/cpu.php?cpu=Intel+Xeon+E5-2680+v2+%40+2.80GHz)

[2]
[http://www.cpubenchmark.net/cpu.php?cpu=Intel+Core+i7-4770+%...](http://www.cpubenchmark.net/cpu.php?cpu=Intel+Core+i7-4770+%40+3.40GHz&id=1907)

~~~
meltedice
That assumes that there's only one chip in the server (unlikely with 36 vcpus
listed for C4), that you're happy with using a desktop chip with no ECC for
Hetzner, and your pricing doesn't consider reserved instance pricing for C4
which costs much less than $1300.

~~~
moe
The ECC version costs $81/mo at Hetzner.

3 years reserved c4.8xlarge costs $501/mo at EC2.

If you can commit for 3 years, why would you pay a 6x markup for "elasticity"?
(11x if you commit for only 1 year...)

~~~
zimfin44
Does that server also provide 36 cores, 60GB of RAM, 10Gbps network and the
fastest Intel CPU available anywhere? You're comparing a single low-end chip
vs a server with multiple cutting edge chips. Everyone knows you pay more for
the fastest chips. If budget is the only criterion then there are many less
expensive instances.

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lukego
Is the Enhanced Networking on a C4 instance a Virtual Function (ixgbev driver)
or a full Physical Function (ixgbe driver)?

The docs say that it is a VF but I wonder since they are offering the full 10G
of bandwidth.

We could relocate our Snabb Lab to AWS if we got PFs.
[https://github.com/SnabbCo/snabbswitch/wiki/Snabb-
Lab](https://github.com/SnabbCo/snabbswitch/wiki/Snabb-Lab)

~~~
smwht
It looks like it still loads the ixgbevf driver:

    
    
      # ethtool -i eth0
      driver: ixgbevf

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pantulis
What does "optimized specifically for EC2" means?

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ejdyksen
Here's the chip in question (Intel Xeon E5-2666):

[http://ark.intel.com/products/81706](http://ark.intel.com/products/81706)

I don't think anyone but Amazon has this specific model. I don't see it
available for sale anywhere.

~~~
api
Interesting trend. If you could spec out the whole thing including cooling for
use in a data center, you could probably do some _really_ damn fast many-core
chips that wouldn't be likely to sell much in the desktop and a la carte
server markets.

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matthewrudy
It's interesting that this new generation has moved away from onboard ssds.

The extra features of EBS SSDs are pretty useful (ie. snapshotting)

But having attached disks was super fast.

~~~
pwarner
I presume they will add storage optimized instances with local disks in the
future?

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matthewrudy
I guess so.

Last time we spec-ed up an ElasticSearch cluster the SSD EBS didn't exist yet,
so on-board SSDs was an obvious win.

I should revisit it again some time.

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otterley
SSD instance storage will always be significantly faster than EBS storage,
even if SSD-backed. I'm disappointed that Amazon dropped it from their C4
offering.

For Elasticsearch, we use R3 (memory-optimized) instances which still have SSD
instance storage. And boy is it ever fast.

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helper
Ugh, very disappointed to see these are EBS only.

~~~
meltedice
EBS disks are far more durable (and convenient with S3 snapshots).

~~~
helper
Besides my database servers, all of my machines are ephemeral[1]. I can lose
machines and spin up new ones automatically (and therefore scale elastically).

EBS adds an unnecessary additional point of failure that I want to avoid at
all costs.

Having run production systems in EC2 since 2010, I've survived numerous EBS
outages as other services have crashed and burned by sticking to this
philosophy.

[1]: I don't use EBS for my database servers either. I use a replicated DB
that can lose multiple machines simultaneously without loss of data (and is
backed up to S3 in case of a catastrophic event).

~~~
kxo
Specifically which database?

~~~
helper
Cassandra.

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pwarner
Should we expext R4 (ram optimized) or M4 (balanced) instances soon or is the
high cost of DDR4 going to delay things?

I am about to reserve some R3 instances so maybe that will speed it up :-)

