THE Sydney Islamic school Malek Fahd has swept into the top 10 HSC performers this year, joining James Ruse Agricultural High, which has maintained first position for the 12th consecutive year.

State selective schools hold seven positions in the Herald's list of top HSC performers.

The private boys' school Sydney Grammar, which is also selective, and Ascham School for girls, are also in the top 10.

Although Malek Fahd Islamic School is not selective, like some other private schools, it has been known to encourage underperforming students to repeat a year or consider another school.

James Ruse, which selects the cream of the state's academic talent, has bettered the success it had last year. The proportion of its year 12 students who scored 90 or above rose from 65 to 74 per cent, the Herald's analysis shows.

Larissa Treskin, who replaced Michael Quinlan as principal of the school last year after he served 15 years, said students had lifted their overall performance in the HSC this year.

"We had a great improvement across the board in the percentage of students in band six [a score of 90 or more]," she said.

"Their teachers are thrilled that all the hard work by everybody has resulted in such great achievements."

Of the school's 48 year 11 students who completed their HSC agriculture exams this year, 45 scored 90 or above, including James Sin, who topped the state.

Hornsby Girls' High School

relinquishes its No.2 position on the Herald's HSC league table, to drop into fifth position in this year's results.

North Sydney Girls' High is ranked second this year, followed by Sydney Girls' High in third position and Baulkham Hills High in fourth.

The first private school to appear on the table is Ascham, in sixth place, swapping the position it held last year with seventh-placed Sydney Grammar.

Malek Fahd is ranked ninth this year and was 15th last year. Sydney Boys' High School is 10th in the table this year and was eighth last year. Malek Fahd and Sydney Boys' High are each ranked in the top five schools for their performance in maths, but close to 40th in English.

The president of the NSW Board of Studies, Gordon Stanley, said there was a record number of all-rounders this year - 1035 students achieved 90 and above in at least 10 units of study. (Most subjects are worth two units, some are worth one and advanced courses are worth three or four.) Last year 800 students scored 90 or more in 10 units.

Professor Stanley said the increase might be the most significant aspect of this year's result.

"The standards are the same but the performance with respect to those standards is up this year," he said.

Professor Stanley partly attributed the increase to a rise in the number of HSC candidates.

He said more students achieved 90 or more in English this year.

Four of the top six schools in the Herald's table are girls' schools.

The first academically non-selective school on the Herald's table is the Conservatorium High, in 39th position, followed by Killara High, in 56th place.

Schools are ranked in this way: the number of credits (90 or more in a subject) a school earns is divided by the number of HSC examinations students at that school sit. It removes the natural advantage had by larger schools.

Raw data, based on the number of credits each school receives, still ranks James Ruse, with 167 year 12 students and 804 credits, in first place and North Sydney Girls' High, with 161 students and 625 credits, second.

If the raw data were used in the Herald's table Baulkham Hills High, with 186 year 12 students and 624 credits, would have displaced Sydney Girls' High, which had 161 students and 533 credits, in third position.