GRE or GPA: which matters more? (with a detailed analysis

The answer to this question is that both matter. You need a high GPA and you also need to get through the GRE. Your essays can help make up for weak spots to some extent. Of course, if there's no way left to fix your GPA, do everything you can to raise your GRE score.

Admissions officers will definitely, certainly, absolutely care about your GPA. If you failed a course in your major (and haven't made it up yet), or your GPA isn't great, it's best to explain why in your main essay or in an optional additional essay. Your essays can explain why your overall GPA is low. For example, some courses are genuinely hard and really do require a lot of papers and assignments. Some of those courses may also not be in your major, so you didn't give them enough attention. And as a new freshman you may not have adjusted to the learning environment yet, or you joined too many extracurricular activities and spread your energy badly.

You can also point out clearly that your grades in junior- and senior-year major courses were excellent, which shows your ability to learn and your foundation in the field. The way your GPA improved can also show problem-solving ability (proof that you can get better)

That said, the GRE really does reflect your English level. If time pressure means you can't raise your score any further, put real effort into polishing your essays to show your command of English indirectly.

To sum up, GPA and GRE are both very important. You can use your essays to explain a weak GPA and highlight your strengths and achievements in other areas. Essays can also show your English ability and problem-solving skills indirectly. Most important of all, prepare thoroughly for your own situation and make the most of your strengths to make your application more competitive.