Researchers Sour on Vista Service Pack 1 Performance

Stony Stevenson passed us a link indicating that a group of researchers has described Microsoft's upcoming Windows Vista Service Pack 1 as basically a performance dud. Researchers from the Devil Mountain Software group is claiming that a series of in-house benchmark tests showed that users hoping to receive a speed boost from the update will be disappointed. "Devil Mountain ran its DMS Clarity Studio framework on a laptop Barth described as a "barn burner" -- dual-core processor, dedicated graphics, and either 1GB or 2GB of memory -- to compare performance of the SP1 release candidate that Microsoft released last week with the RTM version that hit general distribution last January. The Vista RTM was not updated with any of the bug fixes, patches or performance packs that Microsoft has pushed through Windows Update since the operating system's debut. 'One gigabyte, 2GB [of memory], it didn't make a difference,' said [CTO Craig] Barth. 'SP1 was never more than 1% or 2% faster.'"

Comments

Has it ever improved efficiency?

[Ckwop]

Without wishing to troll, when has a Window service pack ever improved the speed of a Windows OS?

In fact, and I'm sure someone on Slashdot has raw data on this (that perhaps even shows I'm wrong), Apple are the only company who has ever achieved this on a regular basis.

I've found in my rather short development career is something scarily similar to the first law of thermodynamics: "Bad code once created can never be destroyed." In most commercial situations, the risk of breaking a routine far outweighs the benefit the change brings.

We've built an entire area of study, refactoring, on trying to sell the importance of keeping code clean. I'm still not 100% convinced that the case for refactoring has been made. If you spend three months refactoring, is the simpler overall structure really going to speed up development sufficiently to justify the capital outlay? In all but the very worst code-bases, the answer is unclear.Bear in mind, refactoring my cause you to notice bugs that you can't fix because it would break an interface. Now your code has to be badly structured to support this bad business logic. This can be enough to render the effort useless.

This is why service packs rarely improve functionality or performance. Windows XP SP2 is a notable exception. The risk is simply too great.

Simon

Re:Optimization

[TheRaven64]

Most worthwhile optimisation is done by rethinking the design, and to a lesser degree hand-coding parts where you know the realities better than the compiler can guess, and just how to exploit that. Micro-optimisations in the right place (not even at the assembly level, just tweaking a few algorithms or data structures, or even the code layout) can give huge benefits. I got a 25% speed gain from some code I was working on a few years ago just be moving a couple of functions into a header and marking them as static inline so the compiler could inline them. Memoisation of frequently-called functions can also give some benefits.

The hard part is usually not the optimisation, it's working out where the optimisations need to go. This typically involves wading through huge amounts of data from profiling runs.