Avoiding Computer Viruses

The first thing to note when discussing computer viruses is that viruses are just programs, sort of like how spam is just email.  Computer users demand the ability to run any program they want, without restrictions, not have any viruses, and also not be asked any questions before running a program.  That is impossible.  I’m going to discuss four common approaches to dealing with the problem of protecting computers from unwanted programs. Continue reading

HTTPS and Web Certificates

When you go to a website and the address says https instead of http or you see a little lock button in the address bar, it means the data being transmitted back and forth is encrypted.  Any other computer along the way on the internet cannot read the contents of the transmissions.  However, sometimes you get a warning about visiting an encrypted site that says your identity is being phished or that you cannot trust the connection.  I’m going to explain what that means and when you should bypass the warning anyway and when you should not. Continue reading

Dropbox Hashing

If you add a file to your Dropbox folder that already exists on Dropbox’s servers, you don’t have to send the file.  They just mark the existing file as also being owned by you.  In fact, Dropbox works on files in 4 MB chunks, so if you modify a large file and most of it remains unchanged, they only need you to upload any 4 MB chunks that changed and don’t already exist somewhere else on Dropbox.  A lot of people are amazed or confused by this technology.  How can Dropbox’s server and your computer know that two 4 MB chunks are the same without comparing them side-by-side? Continue reading

Dropbox International Performance

I recently attended this:

Dropbox: International Performance

Come hear about several recent and future improvements to Dropbox’s international performance. Dropbox Engineer, Nipunn Koorapati, will talk about the Dropbox server architecture as well as recent optimizations to the client-server protocol for small and large files focused on our high latency international users.

We face international performance challenges at Offroad too, with systems in Switzerland and the US.  We have fairly high bandwidth between the sites, but the high round-trip times (latency) leads to problems. Continue reading

Buy Computers This Year

This year’s CES offers some exciting developments in computing.  But first, isn’t it odd that all these products are released just after Christmas?  Maybe it’s because Christmas is more about stores clearing shelves of unsold inventory at the end of the year.  Obligatory gifting customs lead people to buy discounted junk for others.  Stuff that they wouldn’t otherwise want for themselves.

I’ve held off new computer purchases for a long time, waiting for the 14nm chips from Intel.  They’re over a year late, which is understandable considering how amazing they are.  One can only imagine the internal dynamics at Intel, where the management and marketing team want to adhere to a long-term schedule of improvements while the scientists and engineers can only guess how long it will take to develop cutting-edge technology.

Here are the reasons I think 2015 is a good year to upgrade computers:

  • 14nm chips offer reduced power consumption, which means longer battery life, less heat, quieter fans or no fans.  It seems like it’s just another size in a long progression, …45, 32, 22, 14. But this time the performance change will feel like a breath of fresh air, the same way that 64-bit chips alleviated maximum RAM issues or SSD’s solved storage seek times.  And note that a 15W quad-core chip compared to a 45W dual-core chip is going to use even less than 1/3 the power to run a single thread because the power rating is for all the cores.
  • Screens are finally being marketed in terms of resolution.  I even saw a laptop screen quoted in megapixels.  I’ve always said monitors should be evaluated on megapixels and camera sensors on size.  Maybe we just had to max out practical screen sizes and camera sensor resolutions before shifting attention to the other factor.
  • vPro will make remote management of computers much easier.  With it, I can reinstall an OS at the office from across the ocean.
  • The AES-NI (Advanced Encryption Standard New Instructions) should reduce processor workload.  Even if you don’t encrypt all your data, you probably use https, VPN’s, WPA, or something else that uses AES encryption.
  • The Intel Compute Stick is fun.  Imagine the possibilities offered by a computer so small, low powered and inexpensive.  You could have a solar powered computer on your roof.  A computer in your car.  A computer attached to each TV (for people who still use TV’s!).  Sure, all that was possible before with the Raspberry Pi or by turning a smartphone into a PC, but that required effort.

Last year, a new laptop made little sense when compared to a 4 year old laptop.  With similar weight and processor performance, you would get a worse screen, better battery life, and better video performance.  It made more sense to buy a used laptop, throw in an SSD and clean the dust off its heat sinks.  I’m using a 6 year old Precision M6400 and my only complaints are weight and fan noise under heavy load.

I’m recommending the new Intel NUCs with Broadwell chips and the Dell XPS 13.  Personally, I’m going to hold off on a laptop upgrade until the 14nm chips make it into a Precision mobile workstation since I want two hard drives, more built-in ports, and a 15″ or 17″ screen (yeah, screen size also matters a bit).