FRONTEND_MVC/views/_etc/header/header_comments.php

<?php
if(Yii::$app->deviceDetect->isMobile()) return "";
$query = \app\models\base\Comments::find()->andWhere(['visible'=>'Y'])->orderBy(['created_at'=>SORT_DESC])->limit(3);
$view = $this;
?>
<div class="header-center__comments">
    <div class="header-comments">
        <div class="header-comments__wrapper"><h2 class="header-comments__title">Комментарии в&nbsp;эфире</h2>
            <?= Yii::$app->cache->getOrSet("header-comments",function () use ($query,$view){
                $comments=  \yii\helpers\Html::beginTag("ul",["class"=>"header-comments__list"]);
                foreach ($query->all() as $model)
                {
                    $comments.= $view->render('_header_comments_item',['model'=>$model]);
                }
                $comments.= \yii\helpers\Html::endTag("ul");
                return $comments;
            },60);
            ?>
        </div>
    </div>
</div>