以上に details
more than; even more than — exceeds a stated or implied benchmark
今日の試験は思っていた以上に難しかった。
kyou no shiken wa omotte ita ijou ni muzukashikatta.
Today's exam was harder than I had expected. neutral
このラーメン、評判以上にうまいじゃん。
kono raamen, hyouban ijou ni umai jan.
This ramen is even better than its reputation, seriously. casual
Examples
more than; even more than — the outcome exceeds a stated or implied benchmark
今日の試験は思っていた以上に難しかった。
kyou no shiken wa omotte ita ijou ni muzukashikatta.
Today's exam was harder than I had expected. neutral
このラーメン、評判以上にうまいじゃん。
kono raamen, hyouban ijou ni umai jan.
This ramen is even better than its reputation, seriously. casual
今回のプロジェクトは予算以上にコストがかかりました。
konkai no purojekuto wa yosan ijou ni kosuto ga kakarimashita.
This project ended up costing more than the budget allowed. formal
Formation
{N}いじょうにattaches to nounplain clause + 以上にattaches to plain clause
Notes
often drops there too (引き受けた以上、やるしかない), so
the cue is the presence of に (comparison), not に versus は.
Related patterns
Similar
より is a bare comparison between two named items (AはBより高い); 以上に frames the compared item as a THRESHOLD the outcome exceeds, most often the speaker's own prior expectation (思っていた以上に), and reads oddly swapped onto a plain two-item comparison with no benchmark sense.
Lookalikes
The same 以上, but the particle changes the job entirely — 以上は (this file) draws a firm conclusion FROM an established fact; 以上に is the comparison-degree marker "beyond, more than" (想像以上に難しい) with no obligation or resolve involved at all.