Codetaku

Nu intotdeauna socoteala din targ se potriveste cu cea de acasa. La fel si cu optimizarile: nu intotdeauna ceea ce ai calculat se simte si in viata reala.

Spre exemplu in linux poate parea ca fisierele sunt copiate dintr-o parte in alta cu viteza mare si desi este adevarat, viteza comparativa cu Windows poate nu fi asa mare. In linux nu avem progress bar pe cand in windows da. Cam asa este si cu Windows XP vs Windows Vista. Windows Vista care are un algoritm improvizat de copiere fata de XP de fapt copiaza mai rapid fisierele dintr-o parte in alta din 2 motive:
1. Au facut estimarea idioata a timpului de copiere (care dureaza 12 secunde) inainte sa se inceapa copierea
2. Progress bar-ul in Vista ramane permanent pe ecran pana cand se scrie ultimul bit pe cand nu asa se intampla si la XP unde progress barul dispare dupa cache-uirea (copierea in memorie, nu si pe hdd) ultimului bit.

Alt test interesant este acest studiu in care se ruleaza progress baruri care sunt afisate de catre functii diferite dar toate dureaza au aceeasi durata de executie. Persoanele care au participat in acest test nu au stiut ca toate ruleaza la fel de mult si li s-au parut ca unul e mai rapid ca altul.

Mai multe puteti citi si de la Jeff Atwood.

Despre optimizarea performantei cu utilizatorii in gand este interesant acest articol. De aici exemplul cu lifturile mi-a placut foarte mult:

A classic example occurred in the 1930s in New York City, where “users” in a large new high-rise office building consistently complained about the wait times at the elevators. Engineers consulted concluded that there was no way to either speed up the elevators or to increase the number or capacity of the elevators. A designer was then called in, and he was able to solve the problem.

What the designer understood was that the real problem was not that wait time was too long, but that the wait time was perceived as too long. The designer solved the perception problem by placing floor-to-ceiling mirrors all around the elevator lobbies. People now engaged in looking at themselves and in surreptitiously looking at others, through the bounce off multiple mirrors. Their minds were fully occupied and time flew by.

This entry was posted on Monday, March 3rd, 2008 at 22:17 and is filed under Uncategorized. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.