
Ask HN: Inexpensive dedicated servers for testing Skylake? - nkurz
I have some SIMD algorithms that I&#x27;d like to check for performance on recent Intel chips.   In particular, &quot;gather&quot; performance is reputed[1] to be much better on Skylake than earlier processors.
Are there any cloud or dedicated server providers offering these yet?<p>I found http:&#x2F;&#x2F;www.reliablesite.net&#x2F;dedicated-servers&#x2F;quad-core-server&#x2F;intel-core-i7-6700k starting at $99 month.    But I&#x27;d prefer something by the hour rather than by the month, as it&#x27;s really just proof of concept testing at this point, and I can probably do all the testing I need in several hours spread over a couple days.<p>I&#x27;m surprised Intel doesn&#x27;t go more out of their way to make instances on these available to researchers and software developers.   The potential of these newer chips is not reached by existing software, and it would seem to be in Intel&#x27;s interest to encourage more research in to how to take full advantage of them.<p>[1] See &quot;Fig 11-4 Throughput Comparison of Gather
Instructions&quot; in
http:&#x2F;&#x2F;www.intel.com&#x2F;content&#x2F;dam&#x2F;www&#x2F;public&#x2F;us&#x2F;en&#x2F;documents&#x2F;manuals&#x2F;64-ia-32-architectures-optimization-manual.pdf
======
cjbprime
> and it would seem to be in Intel's interest to encourage more research in to
> how to take full advantage of them.

This seems a little overstated -- we're talking about CPUs that are widely
publicly available for around $300 USD, not some big iron.

~~~
nkurz
I don't think it's overstated: Intel would benefit from published research
that plays to the strength of their newer processors, and there is a lot of
published CS research based on older processors because the researchers don't
have access to the newer machines.

The CPU is several hundred dollars, but since it requires a different
motherboard and DDR4 RAM, it would be over $1000 to put together a test system
to meet our needs. The norm is that it just doesn't happen, and that people
publish using a single machine that they replace every couple years.

Consider the plethora of articles published for the last couple years of
showing the very modest improvements in processor performance running existing
software. Then consider the value of just a couple high profile cases of
people showing 2x-4x gains on newer processors using algorithms that target
them.

I think that value would be much higher than the cost of providing access, and
that the absence of such articles is because the hassle and cost of testing on
newer processors is still quite high. Consider the innovative project I just
posted here:
[http://cglab.ca/~morin/misc/arraylayout-v2/](http://cglab.ca/~morin/misc/arraylayout-v2/)
Great project, legitimate research, but no numbers for any Broadwell or
Skylake processors. Or Power8 for that matter.

~~~
jonah
Some time back I was working at a company that made very popular cutting edge
graphics software. Some of the key developers had beige-box machines labeled
"Property of Intel" and "Confidential". Inside were Intel motherboards
populated with pre-release Pentium III CPUs - also etched "Intel
Confidential". These were Katmai machines which the engineers were using to
implement SSE instructions[1] in the software.

So, yes, Intel does supply hardware to key developers. I have no idea what the
criteria is, but next time, talk to your connections and see if your company
or research group qualifies.

[1]
[https://en.wikipedia.org/wiki/Streaming_SIMD_Extensions](https://en.wikipedia.org/wiki/Streaming_SIMD_Extensions)

------
sandGorgon
One way which could work out is to post on /r/gaming and request anyone who
has a Skylake machine to run an Ubuntu liveusb (with openssh-server) and give
you access for a couple of hours. In exchange you could buy them a Steam game.

~~~
firloop
/r/buildapc may be receptive to this as well.

~~~
greenknight
or /r/pcmasterrace

------
twotwotwo
Note Intel said Skylake server chips would introduce AVX-512 instructions, but
Skylake consumer chips don't have those. That could mean the server chips will
have a different vector unit with different performance.

That may not be a huge deal if the gather improvements are all you care about
and they're present in both consumer and server chips. But worth knowing.

~~~
nkurz
Intel coincidentally officially launched the first Skylake Xeon's today:
[http://ark.intel.com/products/family/88210/Intel-Xeon-
Proces...](http://ark.intel.com/products/family/88210/Intel-Xeon-
Processor-E3-v5-Family#@Server)

Interestingly, despite being Skylake server chips, it looks like none of them
support AVX-512. Do you happen to know which models actually will have
support?

Or for that matter, what are all the differences between the "server" E3v5
Xeons and the "consumer" Skylake chips? Support for ECC RAM is the only one I
see at a glance: [http://ark.intel.com/products/family/88392/6th-Generation-
In...](http://ark.intel.com/products/family/88392/6th-Generation-Intel-
Core-i7-Processors#@Mobile)

~~~
twotwotwo
Haha, I saw that and asked the same thing at Anandtech.

These server chips are slight tweaks to consumer chips. They work with server
chipsets [and ECC RAM as you caught!]; don't know what else differs. There
aren't yet "large" Xeons (E5 or E7) on Broadwell or Skylake, only Haswell.

The table of Haswell chips from Wikipedia is the best handle I can quickly get
on the how the server chip line works:

[https://en.wikipedia.org/wiki/Haswell_(microarchitecture)](https://en.wikipedia.org/wiki/Haswell_\(microarchitecture\))

\- E5 and E7 have more cores and L3 cache

\- They also support more sockets (the model numbers start 2, 4, or 8
according to how many sockets they support)

\- They're released a lot later: the first Haswell chip was in June 2013, but
all the E7s in the tables are listed as May 2015.

And Haswell is v3 so Broadwell is v4 and Skylake is v5.

If this roadmap is right, larger Broadwell chips will come next year and large
Skylake Xeons might not be until 2017(!):

[http://www.theplatform.net/2015/05/26/intel-lets-slip-
broadw...](http://www.theplatform.net/2015/05/26/intel-lets-slip-broadwell-
skylake-xeon-chip-specs/)

I was vaguely aware that architectures would mature before working their way
up the server line, but not of how long that pipeline was. Anyway, guess we
shouldn't hold our breath!

------
tadfisher
If you want to provide a USB-bootable image, I'd be happy to run whatever
you'd like on my 6700k system.

~~~
nkurz
Thanks for the offer. I'll see what else turns up. I'm looking both for an
immediate solution as well as a longer term one, so would prefer to find
something inexpensive that can be repeated easily for future tests.

------
voltagex_
Tweet Intel maybe? Stranger things have happened

------
kawera
Not by the hour but very inexpensive:
[https://www.hetzner.de/en/hosting/produktmatrix/rootserver](https://www.hetzner.de/en/hosting/produktmatrix/rootserver)

~~~
nkurz
I currently rent a Haswell server from Hetzner (and love them) but I'm not
seeing anything more recent than that. Am I missing them somewhere?

------
toast0
Intel server chips are usually about a year behind desktop chips. Broadwell
was delayed for desktop and will likely be delayed for server too. Most of the
providers advanced enough to offer hourly pricing are running server (xeon)
chips for their whole fleet, so expect a wait. Skylake Pentiums are supposed
to be in the market now (but aren't), so that might be a lower cost option.

------
ck2
Isn't a heavily virtualized environment not going to give you actual
performance or access to full cpu features?

------
vardump
Just buy a Supermicro Xeon v5 motherboard (when one becomes available!) and of
course a Skylake Xeon E3 v5. $300 motherboard and $300 CPU. Minimal whole
system should be about $1200.

Not affiliated with Supermicro, I just like their features and pricing.

------
codinghorror
The point of most cloud servers is to abstract away the kind of low level
architectural details you are looking at here, so kind of opposing goals.. why
not just build a little Skylake home desktop and try it there? It is not
expensive, maybe $800 tops and you get a nice development rig in the process.

~~~
nkurz
_Why not just build a little Skylake home desktop and try it there?_

Because I've already got a nice laptop, and several underutilized older
servers. I'd like to test on Sandy Bridge, Haswell, Broadwell, Skylake, ARM,
and Power8. The older Intel processors are easily available,
[https://www.runabove.com/](https://www.runabove.com/) gives me access to
Power8 (and supposedly ARM, although I haven't tried it yet), but I haven't
yet found inexpensive ways to test on Broadwell and Skylake.

For this particular case, I was hoping to just spend a few hours testing some
SIMD variants of this:
[http://cglab.ca/~morin/misc/arraylayout-v2/](http://cglab.ca/~morin/misc/arraylayout-v2/)
The Haswell performance is disappointing, but I think that's because the
Haswell AVX2 gather performance is poor but Skylake is supposedly much better.
See the link I gave earlier for details.

~~~
i336_
I checked RunAbove with great curiosity, but the site seems to be indicating
that the Power8 option is unavailable / "closed".

Does this mean all new projects are rejected, that they're trying to halt new
applications, or what?

Also, are you the author of the 2nd link? I tried it, my `free' doesn't have
`-h' (Slackware 14.1, procps 3.2.8, manpage says "Cohesive Systems / 20 Mar
1993").

~~~
nkurz
_I checked RunAbove with great curiosity, but the site seems to be indicating
that the Power8 option is unavailable / "closed"._

I'm not sure. I signed up during a Beta window last year, and don't know where
they are going with it overall.

Also, I haven't used it in a few months, and when I tried right now I got
errors on creating a new instance. I opened a support ticket.

 _Also, are you the author of the 2nd link? I tried it, my `free ' doesn't
have `-h'_

No, I'm not the author. Searching though, it looks like "-h" is a synonym for
"human readable" on some distributions, and just does automatic units.

~~~
nkurz
I fear that RunAbove is no longer a viable way of testing on Power8. The
response to my trouble ticket was so unhelpful that it did not even confirm
whether they still expect a Power8 instance to start. Instead, they just
referred me to the community support which consists of lots of unanswered
questions with the same symptoms. I would suggest avoiding RunAbove altogether
-- truly abysmal service.

