Laptop comparisons

So after a bit more research, I’ve come up with a shortlist of laptops to consider. Most vendors (with the exception of HP and Microsoft) give you quite a few options to customise during the order process. For my own reference, I’ve also included the specs of my current laptop – the Dell XPS 1645 – to contrast how hardware has progressed over the last 5-6 years.

My mandatory minimum requirements:

• i7 CPU
• 8GB memory
• 512GB SSD
• Touch screen
• Lighter than 3Kg

Nice to haves:

• Xeon CPU
• 16GB memory
• PCIe SSD

Laptop feature comparison | | Dell XPS 1645 (Circa 2010) | Dell XPS 13(9350) | Dell XPS 15 (9550) | Dell Latitude E7450 | HP ZBook Studio 15 E3 Mobile Workstation

ThinkPad X1 Yoga - Core i7

Microsoft Surface Book

Intel Core i7-6600U Processor (up to 3.40GHz)

i7-6600U (2.6 up to 3.4 GHz)

4MB

4 MB

512GB Solid State Drive, PCIe-NVMe

Intel(R) HD Graphics 520

Intel® Integrated HD Graphics 5500

Intel HD Graphics 520

Intel HD Graphics 520 + Nvidia GeForce 940M GPU with 1 GB of memory

14” FHD (1920x1080), IPS, 10-point Multi-Touch

802.11ac Wi-Fi wireless networking; IEEE 802.11a/b/g/n compatible Bluetooth 4.0

4 Cell Li-Polymer Battery 52Wh

337 x 232 x 20

Notes

• Where choice was offered, maximum CPU and memory selected
• All prices in Australian dollars, including GST. Enterprise agreements or other arrangements/discounts/specials might give better prices.
• Enterprise and/or special business programs may offer additional hardware choices/customisations.
• Where offered, 3 year support was chosen
• No Office subscription was included
• Windows 10 Pro 64bit

Thoughts

I think I’ll forget about a Xeon CPU - can’t justify the premium price. Maybe one day!

Most of these devices have built-in batteries, so the option of buying a spare battery (like I did with my 1645) simply doesn’t exist these days.

Looking at that list, I think the models that stand out are the XPS 15, X1 Yoga and Surface Book. I’ve probably been looking most closely at the Yoga, but the XPS deserves some closer attention – especially as the price seems a bit more affordable. The Surface Book looks nice, but for me I think it’s in 3rd place behind the other two.

Let me know of any corrections or suggestions for other models that I should consider and anything I’ve overlooked.

Book review: Why

As part of their support for user groups, O’Reilly sent me a free copy of “Why: A Guide to Finding and Using Causes ” by Samantha Kleinberg to review.

Kleinberg is an Assistant Professor of Computer Science, so I was interested to see what she had to say about finding “causes”. It probably wouldn’t be the first book I chose if I was browsing, but I’m always interested in learning new things.

What I liked about this book was the use of written examples and illustrations. The first chapter opens with the story of Sally Clark. A tragic miscarriage of justice that resulted in Clark serving 3 years in prison for the murder of her babies. One of the significant pieces of evidence that was used to convict Clark was the suggestion that the probability of two babies dying of SIDS was 1 in 73 million. This is wrong, because the witness (a medical expert) didn’t understand statistics and probability. The expert witness believed Clark was the cause of death the two babies.

The Clark story isn’t the only one told. I’m glad for the generous sprinkling of those examples – without which it would be pretty dry going. It is very helpful to bring things back to something you can relate to.

A warning, this is a pretty in-depth book. I can’t say I found it an easy read, but there’s plenty of detail there.

Before reading this book I guess I assumed that finding the cause for something was a pretty straight forward. Turns out the correct method is “it depends”.

Trying to identify the real cause of an event is not always easy. Kleinberg takes us on a journey to better understand ways (and there are more than one) of finding causes – Beginnings (concepts), Psychology (how do we learn about causes), Correlation (correlation and causation aren’t the same thing), Time, Observation (watching to learn), Computation (automating the process), Experimentation (experiments and research), Explanation (this caused that), Action (making decisions).

The writer comes from the Computer Science field but she writes in a generally accessible (if a little bit academic) way. There are plenty of references (the notes and bibliography take up a not insignificant amount of the book). I noticed a lot of examples were medically-related, so if you work in the medical field, then I think you would get a lot out of it too.

Finally, a suggestion for the title of the sequel – “Just Because” 😀

Backwards compatible ignoring Roslyn Analyzer warnings

The “Roslyn” Analyzers are a great new feature that shipped in Visual Studio 2015. One nice thing about them, is you can still add them to a project even if the target platform for a project is not .NET 4.6. This makes sense, as the analyzers just run as part of the compiler – they don’t affect the generated code in any way.

This also means you can safely add analyzers to a project and get all the warnings/errors when using Visual Studio 2015, but you can still open the same project in an older version of Visual Studio and the analyzers are just ignored.

Sometimes you want to suppress a specific warning. It turns out there’s two ways to do this:

SuppressMessageAttribute

The first is the same that you would have done to suppress an old FxCop/Code Analysis violation – using the System.Diagnostics.CodeAnalysis.SuppressMessageAttribute attribute.

[SuppressMessageAttribute(“Microsoft.Performance”, “CA1811:AvoidUncalledPrivateCode”)]

It turns out, the only bit that Roslyn really cares about is the second parameter. As long as it starts with a valid CheckId, then that violation will be suppressed. My observation is that the first parameter (category) doesn’t seem to matter too much.

[SuppressMessageAttribute(“StyleCop”, “SA1514”)]

Pragmas

The new compiler is much more flexible in disabling warnings and errors. You can now use a compiler pragma to disable a particular warning or error code – and the code isn’t just for the C# language, it can be for an analyzer too. eg.

#pragma warning disable SA1514

One advantage to using pragmas is that you can re-enable them if you want to limit the scope of the pragma to just a particular block of code in a single file.

Backwards-compatible pragmas

The only problem with the pragma approach above is if you try and compile the source code with the older non-Roslyn C# compilers. They haven’t ever heard of this ‘SA1514’ that you’re referring to and will generate a compiler error. The workaround is to wrap the pragmas with a conditional block, like this:

#if VS2015

#pragma warning disable SA1514

#endif

The final part is to define ‘VS2015’. Do this by editing the .csproj file and adding the following block (insert it after the last configuration/platform-specific PropertyGroup)

<PropertyGroup>
  <DefineConstants Condition="$(VisualStudioVersion) &gt;= 14 ">$(DefineConstants);VS2015</DefineConstants>
</PropertyGroup>

This has the effect of defining a conditional constant only when we’re compiling with Visual Studio 14 (aka 2015) or above. For earlier versions, the constant is undefined and so the pragma is not visible to the compiler.