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Cost comparison: Solaris/SPARC vs Linux/x86

I ran into a little story on siliconrepblic.com last week which started like this:

Cost drives firms from UNIX to Linux

28.11.2007 - Almost two thirds of Irish IT experts say the main motivation for migrating to the Linux operating system from UNIX for use in servers is cost, according to a recent survey from Novel's Open Enterprise Summit in Dublin.

While cost may be a key driver, 48pc of those surveyed felt that hardware obsolescence and modernization issues were contributory factors, while 39pc felt that support issues relating to UNIX was a concern.

Now, in reality, Linux is exactly what it set out to be: "a free Unix for the 386" - the distinctions this story appeals to got started as a cynical Red Hat strategy aimed at exploiting the ease with which people could port from one Unix to another to make sales against Sun instead of Microsoft, and have no basis in reality.

In reality, the cost/performance balance for Linux and Solaris on x86 today is exactly what it was in 1995: they're both free and if you run them on the same hardware there's no cost difference.

Still, perception can become reality and everyone knows what Novel means here: that Linux on Intel is cheaper than Solaris on SPARC - and that raises a question: is what they mean any closer to being true than what they say?

There are four main cost groups to look at: OS licensing, hardware, application licensing, and long term operating costs.

Here's what Sun blogger Jim Laurent had to say about the OS licensing side of this:

Those who have seen me speak to customers, know that I have a "mantra" when asked to compare Solaris to various Linux distributions.  It goes like this:

As a result, one FAQ I get is, "How much less does Solaris 10 cost?"  According to our Sun site and the Red Hat site list price comparisons for support and licenses are:

   Standard service
1 year
(5 x 12)
Premium service
1 year
(7 x 24)
Solaris 10 (up to 2 sockets)
 $720 $1080 
Solaris 10 (unlimited sockets)
$1320 $1980

Red Hat Enterprise Linux 5 (up to 2 sockets)

 11-20% more than Solaris
Red Hat Enterprise Linux 5 (unlimited sockets)
$1,499$2,49913-26% more than Solaris


Hmmmm....  So much for the idea that "Linux is cheap or free." 

He's talking about Red Hat, but what he says is broadly true for other Linux releases, including SuSe: you can run either Linux or Solaris for free, but if you choose to pay for support, Linux costs more.

The hardware side of this isn't much harder to figure out. First, there's obviously no cost difference in the x86 world - your hardware costs don't change whether you choose to run Solaris or Linux because you can choose your OS after you get the hardware.

Compare x86 costs to RISC costs and you run into a scaling problem - but in the specific case of current generation UltraSPARC versus x86, the entry point for x86 is considerably below that for UltraSPARC, but get into the UltraSPARC performance range and it's significantly cheaper than x86.

Check out Sun's benchmark page for their coolthreads line and you'll see they own every price/performance comparison in their weight class - usually by margins comparable to that achieved in the notesbench test I mentioned yesterday.

So the bottom line on hardware is comparable to that on software licensing: for comparable performance levels, UltraSPARC is cheaper than x86.

The software licensing comparison is somewhat similar. First, if you're dealing with open source software the costs are the same - so the question comes down to cost comparisons across licensed products ranging from little known stuff like Maple and FrameMaker to widely licensed products like Oracle's database and applications.

Most specialty product makers, including Maplesoft, are retreating from OS based pricing - meaning that the base cost is the same regardless of run-time environment. Others, like Adobe, continue to support their Solaris customer base but don't yet have a Linux release.

In both cases, however, a Solaris network license delivered via Sun Rays costs significantly less per user than wintel per client licensing (for Adobe) or Lintel per client licensing (for Maplesoft).

Something similar is going on with enterprise class software. Look at Oracle, and the UltraSPARC has a significant pricing advantage over Lintel. There are two components to this: first, for standard edition products both the T1/T2 and Intel multi-core chips count as one processor and so pricing is the same - but since the CMT/SMP machines rather handily outperform the Xeons you get more bang for the same bucks with UltraSPARC.

Secondly, for enterprise and related products Oracle charges per core - but CMT cores count for 0.25 processors while x86 cores count as 0.5 each. As a result a four core x86 license costs the same as an eight core CMT license - and, again, the performance advantage makes the UltraSPARC cheaper - provided your performance needs put you into the hardware range where the benefit applies.

Long term costs generally come in three forms: staffing, space, and power. On the SWaP metric (Space, watts, and performance) the UltraSPARC CMT machines typically beat x86 servers by factors of two to eight (depending on your cost mix) - meaning that as long as your performance needs get you into the low end of the CMT/SMP range, your space and power costs for UltraSPARC will be significantly below those for comparable Lintel capacity.

The staffing issue is the hardest to settle. Workloads are significantly affected by user desktop choices - companies using Sun Rays don't need help desks and and get improved user productivity by shifting application help to key users - but not by Unix server OS choices.

Notice, however, that the issue here is bottom line significance, not FTEs. A Solaris/CMT data center will unambiguously need fewer FTEs than one running Linux on x86 simply because there are fewer machines to administer and Solaris includes a range of powerful administrative tools - from ZFS to the systems management framework and hardware predictive self-healing - that are not available on Lintel. However, the numbers involved are small and many people believe that competent Linux staff can be had for less than comparably competent Solaris staff. We don't know, therefore, which is really cheaper staffing for Lintel or staffing for Solaris on UltraSPARC - all we can say with reasonable certainty is that for data centers needing at least two sysadmins, the Solaris/CMT choice will require fewer FTEs.

So what's the bottom line? That Unix vs. Linux thing is a lie on its own but investigate what's really meant and you find that Solaris on UltraSPARC is generally cheaper than Linux on x86 on licensing and support, on tools and applications licensing, on hardware, and on SWaP while requiring fewer FTEs in the data center - but because those FTEs may, or may not, cost more money individually we don't know if staffing costs are higher, comparable, or lower.

Paul Murphy wrote and published The Unix Guide to Defenestration. Murphy is a 25-year veteran of the I.T. consulting industry, specializing in Unix and Unix-related management issues.