Adventures in Computer Buying and the Curious Case of Safe Mode

In recent days I have advised QRS II users on the purchase of new computers. Sometimes my advice conflicts with IT managers at public agencies. These IT managers have mainly four objectives:  protect the integrity of the network; adhere to purchase protocols and contracts; increase standardization to make life easier for themselves; and reduce costs. A QRS II user has just one objective: get runs done as quickly as possible.

You may have noticed a trend is CPU technology lately.  Chips are not running much faster, as measured by GHz’s, than they did 10 years ago, but they have many more cores, each core being more efficient and cooler. My advice is simple: buy a computer designed for gamers. Gaming computers are optimized for the very sort of computation done by QRS II, and since they are stock items they are reasonably priced. The great graphics capabilities on these computers are mostly unimportant, so it is possible to save a few hundred dollars by downgrading the graphics option to the lowest available. More specifically, get a gaming computer with a CPU having close to the highest benchmark score on the PassMark web page and within your budget. Gamers favor computers with 8-12 GB of highest-speed RAM and a solid state “hard” drive, and these will also help QRS II run well. IT managers may not be totally comfortable buying a computer with an extraterrestrial on the case, but true beauty lies inside the shell. Alternatively, you might be able to configure a conventional computer to match these gaming specifications within whatever vendor contracts that may already be in place.

Personally, I do all of my software development on a laptop computer. I recently replaced my 6-year old Dell with an ASUS mid-level gamer laptop. Previously, I could not run some of the largest travel models on my development computer, but now I can.  The ASUS, weighing about 4 pounds, is almost as fast as my 5-year old Alienware Area 51, weighing 100 pounds, at the University. Using published benchmarks at this time, the best i7 computer should be roughly twice as fast as my ASUS.

The key to fast QRS II runs is the number of threads on the CPU. QRS II tries to use all the threads available. An Intel chip with 4 cores and 2 threads per core will run approximately 4 times faster than a chip with a 2 cores and no hyperthreading at the same CPU speed. However, there will eventually be a point of diminishing returns, which I have not yet observed. Theoretically, with a lot of threads the computer will be unable to serve all the requests for data from memory, since each thread is trying to access the same data arrays simultaneously. Also, the operating system imposes overhead on each new thread it is trying to manage.

I am a little worried about heat, as you should be. I would prefer not to melt my shiny new computer. A few years back I did indeed melt the GPU on an HP laptop, for which HP grudgingly agreed to replace the motherboard.

When working with WisDOT on a computer purchase a few months ago, we discovered a curious aspect of Windows 7. It seems that computers run QRS II almost twice as fast in safe mode than in normal mode.           This speed decrease in normal mode does not seem be caused only by virus checking and indexing, since we tried to defeat both of these services on the test computers. The comparison is not as stark on my new laptop running Windows 10, where runs take about 33% less time in safe mode. I can only guess at the cause. Windows 7 likely loads many services that are inhibiting performance, but I have no idea which services are doing the most slowing. When I look at the Task Manager while QRS II is running, it shows QRS II getting up to 98% of the CPU. How can the other 2% be causing so much damage?

So during a recent conversation I suggested to a QRS II user to try running in safe mode. Not possible, he responded. You see the IT folks in his agency will not allow him to boot the computer into safe mode. Apparently, such a situation makes the computer intolerably less secure. Sigh.

Alan Horowitz, Whitefish Bay, January 3, 2016