Translation:The performance of this computer is better than the performance of my computer.
Is the plural form preferable in this case or it possible to use here singular ביצוע as well?
Speaking of computers, the plural seems preferable, but the singular exists as well, especially in non-technical contexts: הָרַעֲיוֹן נָאֶה אֲבָל בִּצוּעַ אֵינוֹ קַל "The idea is fine, but the execution is not easy" or הַבִּצוּעַ הַמּוּסִיקָלִי שֶׁלוֹ טוֹב "his musical performance is good".
I got this sentence on the app (Android) in the "select words to translate" type of exercise and the full solution was already displayed.
Me too. But I guess that it isn't a big problem since it happens just few times.