{"id":396,"date":"2026-02-04T14:37:04","date_gmt":"2026-02-04T14:37:04","guid":{"rendered":"https:\/\/server.ua\/en\/blog\/?p=396"},"modified":"2026-03-19T11:06:52","modified_gmt":"2026-03-19T11:06:52","slug":"how-an-incorrect-cache-size-leads-to-constant-website-delays","status":"publish","type":"post","link":"https:\/\/server.ua\/en\/blog\/how-an-incorrect-cache-size-leads-to-constant-website-delays","title":{"rendered":"How an Incorrect Cache Size Leads to Constant Website Delays"},"content":{"rendered":"\n
\"A
Incorrect caching settings affect site speed<\/figcaption><\/figure>\n\n\n\n

Page load speed is usually treated with radical fixes: upgrading to a more expensive hosting plan, compressing images down to pixels, or rewriting code. But often the problem lies in the layer that was supposed to speed everything up. We\u2019re talking about caching. When its size is set \u201cout of thin air,\u201d the site starts behaving unpredictably: sometimes it flies, sometimes it freezes on the spot with no visible reason.<\/p>\n\n\n\n\n\n\n\n

How the waiting mechanics work in practice<\/h2>\n\n\n\n

Cache is not just a temporary folder, but a strategic buffer in server memory. When a user opens a page, the server usually has to do a lot of work: query the database, pull settings, process PHP scripts, and assemble everything into a ready page. It\u2019s a heavy process. Cache allows doing this once, saving the result, and then the next 100 or 1000 times simply returning a ready \u201csnapshot\u201d from RAM.<\/p>\n\n\n\n

The problem is that this buffer has very real limits. If you allocate too little space for it, it turns into a bottleneck. If too much, it starts \u201ceating up\u201d the resources needed for the system itself.<\/p>\n\n\n\n

The \u201crevolving door\u201d effect when cache is too small<\/h2>\n\n\n\n

Imagine you have an online store with several thousand products, and the cache can only hold a hundred. As soon as the limit is reached, the system has to delete old entries to write new ones. This is called eviction.<\/p>\n\n\n\n

In practice, this creates chaos. Data that might be needed by a visitor a second later gets wiped, and the server is forced to run the full processing cycle again. This creates the illusion of a \u201cbroken\u201d site: one click responds instantly, the next makes you wait 3-5 seconds. Meanwhile, the CPU is working at its limit, constantly recalculating what it just removed from memory. For the site owner, it looks like constant lag, even though traffic hasn\u2019t really increased.<\/p>\n\n\n\n

When more does not mean better<\/h2>\n\n\n\n

There is a temptation to allocate a large share of RAM to caching, especially on a VPS<\/a>. But here another trap appears. The operating system also needs room to operate: for disk I\/O, network protocols, and the database itself.<\/p>\n\n\n\n

When cache takes almost all available memory, the system kernel has nowhere to go and turns on swap. This is when data from RAM starts being offloaded to disk just to free some space. Since even the fastest SSDs are dozens of times slower than RAM, the site\u2019s response time drops dramatically. At this point, the server is literally \u201cchoking\u201d on its own acceleration settings. Instead of a boost, you get a system that can barely move.<\/p>\n\n\n\n

Subjective perception what a person feels<\/h2>\n\n\n\n

For a visitor, technical details about megabytes or swap files do not exist. They see the result: the page loads, but images \u201carrive\u201d with a delay, or the add-to-cart button does not respond instantly. These micro-pauses of one or two seconds are the worst thing that can happen to a commercial site. They are not long enough to make a person leave immediately, but enough to cause subconscious irritation.<\/p>\n\n\n\n

When the interface behaves unevenly, a sense of instability appears. The customer starts worrying that the payment might fail or the order might get lost, because \u201cthe site feels weird.\u201d This is pure psychology, and it directly converts into lost revenue.<\/p>\n\n\n\n

The role of infrastructure and \u201ccold\u201d start<\/h2>\n\n\n\n

Caching efficiency strongly depends on what your project runs on. On powerful dedicated servers with plenty of memory, a misconfiguration can go unnoticed for quite a while. But on cloud hosting or budget plans, where resources are strictly limited, the wrong cache size shows its downside immediately.<\/p>\n\n\n\n

Another nuance is the so-called \u201ccold cache.\u201d After a server reboot or clearing settings, the site will work slowly at first, until memory fills again with \u0430\u043a\u0442\u0443\u0430\u043b\u044c\u043d\u044b\u0435 \u0434\u0430\u043d\u043d\u044b\u0435. If the cache size is chosen incorrectly, it will never become \u201cwarm\u201d \u2013 data will be evicted faster than it brings any benefit.<\/p>\n\n\n\n

How to recognize the problem without a programmer<\/h2>\n\n\n\n

The main indicator is illogical speed behavior. If the site \u201cflies\u201d at 2 a.m. but clearly slows down at 11 a.m., while the CPU is only a third loaded, most likely the issue is with memory and cache. Constant response \u201cjumps,\u201d when the same page loads fast one moment and slow the next, almost always point to a cache that is too small and constantly refreshing.<\/p>\n\n\n\n

Proper configuration is not a universal recipe, but a result of observation. An online store with a large catalog needs one approach, while a news site where people read only the last three articles needs a completely different one. Only by finding the balance between data volume and the real capabilities of the server can you achieve that \u201cseamless\u201d operation, where the user does not even think about speed, because it is simply there.<\/p>\n","protected":false},"excerpt":{"rendered":"

Page load speed is usually treated with radical fixes: upgrading to a more expensive hosting plan, compressing images down to pixels, or rewriting code. But often the problem lies in the layer that was supposed to speed everything up. We\u2019re talking about caching. When its size is set \u201cout of thin air,\u201d the site starts […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[189,53,112],"class_list":["post-396","post","type-post","status-publish","format-standard","hentry","category-servers","tag-cache","tag-server-configuration","tag-website-optimization"],"_links":{"self":[{"href":"https:\/\/server.ua\/en\/blog\/wp-json\/wp\/v2\/posts\/396","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.ua\/en\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.ua\/en\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.ua\/en\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/server.ua\/en\/blog\/wp-json\/wp\/v2\/comments?post=396"}],"version-history":[{"count":3,"href":"https:\/\/server.ua\/en\/blog\/wp-json\/wp\/v2\/posts\/396\/revisions"}],"predecessor-version":[{"id":479,"href":"https:\/\/server.ua\/en\/blog\/wp-json\/wp\/v2\/posts\/396\/revisions\/479"}],"wp:attachment":[{"href":"https:\/\/server.ua\/en\/blog\/wp-json\/wp\/v2\/media?parent=396"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.ua\/en\/blog\/wp-json\/wp\/v2\/categories?post=396"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.ua\/en\/blog\/wp-json\/wp\/v2\/tags?post=396"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}