{"id":1035,"date":"2019-11-27T15:41:29","date_gmt":"2019-11-27T07:41:29","guid":{"rendered":"http:\/\/149.129.74.185\/?p=1035"},"modified":"2019-11-27T15:41:29","modified_gmt":"2019-11-27T07:41:29","slug":"%e8%ae%a1%e7%ae%97%e6%9c%ba%e4%bd%93%e7%b3%bb%e7%bb%93%e6%9e%84week-11-note","status":"publish","type":"post","link":"http:\/\/www.magicmipamipa.com\/?p=1035","title":{"rendered":"[\u8ba1\u7b97\u673a\u4f53\u7cfb\u7ed3\u6784]Week 11 Note"},"content":{"rendered":"<p>Tag = address &#8211; index &#8211; offset<\/p>\n<p>\u5185\u5b58\uff1a<strong><span style=\"color: #ff99cc;\">\u8003\u8651\u6d41\u6c34\u5316<\/span><\/strong>\uff0c\u6ca1\u6709\u8bbf\u5b58\u9002\u914d\u65f6\u7684\u7406\u60f3CPI = 1.1<\/p>\n<p>\u6d41\u6c34\u7ebf\uff1a<span style=\"color: #ff99cc;\"><strong>\u6ca1\u6709\u6d41\u6c34\u7ebf\u7ade\u4e89<\/strong><\/span>\u7684\u5f71\u54cd\u7684\u7406\u60f3CPI = 1<\/p>\n<p>&nbsp;<\/p>\n<p>Example 1 :<\/p>\n<ul>\n<li>Clock Rate = 200 MHz( 5ns per cycle )<\/li>\n<li>Ideal(no misses) CPI = 1.1<\/li>\n<li>50% arith\/logic<\/li>\n<li>30% ld\/st<\/li>\n<li>20% control<\/li>\n<\/ul>\n<ul style=\"list-style-type: circle;\">\n<li>Suppose 10% of memory oprerations get 50 cycle misss penalty<\/li>\n<li>Suppose 1% of instructions get same miess penalty<\/li>\n<\/ul>\n<p>\u6c42 CPU time \u548c AMAT\uff08\u5e73\u5747\u7f13\u5b58\u65f6\u95f4\uff09\uff1f<\/p>\n<p>CPI = ideal CPI + average stalls per instruction<\/p>\n<p style=\"padding-left: 30px;\">= 1.1 + 0.3*0.1*50 + 1 * 0.01 * 50 + 3.1<\/p>\n<p>CPU time = CPI * IC * Clock Cycle<\/p>\n<p>AMAT = 1\/1.3 * [1+0.01*50] + (0.3\/1.3)*[1+0.1&#215;50]=2.54<\/p>\n<p>&nbsp;<\/p>\n<p>Example 5:<\/p>\n<p>MPI = 1.5<\/p>\n<p>CPI = 2<\/p>\n<p>CC = 1.0ns<\/p>\n<p>cache = 64K<\/p>\n<p>block = 64B<\/p>\n<p>direct-map miss rate = 1.4%<\/p>\n<p>two-way miss rate = 1.0%<\/p>\n<p>Average memory accesstime<sub>direct<\/sub> = 1+(0.014*75%) = 2.05 ns<\/p>\n<p>Average memory accesstime<sub>2-way<\/sub> = 1*1.25+(0.01*75%) = 2.0 ns<\/p>\n<p>CPU time<sub>direct<\/sub> = IC*(2*1.0 + (1.5*0.014*75)) = 3.58*IC<\/p>\n<p>CPU time<sub>2-way<\/sub> = IC*(2*1.0*1.25+(1.5*0.010*75)) = 3.63*IC<\/p>\n<p>&nbsp;<\/p>\n<p><code>AMAT = HitTime + MissRate * MissPenalty<\/code><\/p>\n<p>\u63d0\u5347AMAT\u7684\u6027\u80fd -&gt; \u964d\u4f4eAMAT<\/p>\n<p>&nbsp;<\/p>\n<ol>\n<li>Reduce the miss penalty<\/li>\n<li>Reduce the miss rate<\/li>\n<li>Reduce the miss penalty and miss rate via parallelism<\/li>\n<li>Reduce the time to hit the cache<\/li>\n<\/ol>\n<p>&nbsp;<\/p>\n<h5><span style=\"font-family: 'trebuchet ms', geneva, sans-serif;\">Reduce the miss Penalty\u00a0<\/span><\/h5>\n<p>Multilevel Caches<\/p>\n<p>Critical Word First and Early Restart \u5173\u952e\u5b57\u4f18\u5148\u548c\u5c3d\u65e9\u91cd\u542f\u52a8<\/p>\n<p>\u5148\u4f20\u5757\u91cc\u60f3\u8981\u7684\u5b57\u8282\uff0c\u518d\u4f20\u6574\u4e2a\u5757\u3002<\/p>\n<p>\u8bfb\u5230\u5173\u952e\u5b57\u5c31\u542f\u52a8\uff0c\u800c\u4e0d\u662f\u8bfb\u5b8c\u6574\u4e2a\u5757\u624d\u542f\u52a8\u3002<\/p>\n<p>Giving Priority to Read Misses over Writes \u7ed9\u8bfbmiss\u9ad8\u4f18\u5148\u7ea7<\/p>\n<p>Merging write Buffer \u5408\u5e76\u5199\u7f13\u51b2<\/p>\n<p>\u628a\u8fde\u7eed\u7684\u5730\u5740\u53d8\u6210\u4e00\u4e2a\u5757\uff0c\u4e00\u6b21\u6027\u5199\u5165<\/p>\n<p>Victim Cache \u727a\u7272Cache<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Tag = address &#8211; index &#8211; offset \u5185\u5b58\uff1a\u8003\u8651\u6d41\u6c34 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[21,16],"tags":[],"_links":{"self":[{"href":"http:\/\/www.magicmipamipa.com\/index.php?rest_route=\/wp\/v2\/posts\/1035"}],"collection":[{"href":"http:\/\/www.magicmipamipa.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.magicmipamipa.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.magicmipamipa.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.magicmipamipa.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1035"}],"version-history":[{"count":1,"href":"http:\/\/www.magicmipamipa.com\/index.php?rest_route=\/wp\/v2\/posts\/1035\/revisions"}],"predecessor-version":[{"id":1037,"href":"http:\/\/www.magicmipamipa.com\/index.php?rest_route=\/wp\/v2\/posts\/1035\/revisions\/1037"}],"wp:attachment":[{"href":"http:\/\/www.magicmipamipa.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1035"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.magicmipamipa.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1035"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.magicmipamipa.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1035"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}