А так делаются просто ограничения: "nTopCount":
$res = CIBlockElement::GetList(
$arOrder = Array("SORT"=>"DESC" ;) ,
$arFilter = array('IBLOCK_ID'=>1),
$arGroupBy = false,
$arNavStartParams = Array("nTopCount"=>4)
;) ;
$res = CIBlockElement::GetList(
$arOrder = Array("SORT"=>"DESC" ;) ,
$arFilter = array('IBLOCK_ID'=>1),
$arGroupBy = false,
$arNavStartParams = Array("nTopCount"=>4)
;) ;